WO2015046545A1 - Method and device for measuring thermal diffusivity - Google Patents

Method and device for measuring thermal diffusivity Download PDF

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Publication number
WO2015046545A1
WO2015046545A1 PCT/JP2014/075968 JP2014075968W WO2015046545A1 WO 2015046545 A1 WO2015046545 A1 WO 2015046545A1 JP 2014075968 W JP2014075968 W JP 2014075968W WO 2015046545 A1 WO2015046545 A1 WO 2015046545A1
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Prior art keywords
temperature
temperature wave
wave absorption
heater
heat capacity
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PCT/JP2014/075968
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French (fr)
Japanese (ja)
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高弘 大村
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ニチアス株式会社
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Publication of WO2015046545A1 publication Critical patent/WO2015046545A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/18—Investigating or analyzing materials by the use of thermal means by investigating thermal conductivity

Definitions

  • the present invention relates to a method and apparatus for measuring thermal diffusivity, and more particularly to a method and apparatus for measuring thermal diffusivity by a periodic heating method.
  • a periodic heating method which is an unsteady method in addition to a guarded hot plate (GHP) method which is a steady method and a heat flow meter method.
  • GFP guarded hot plate
  • a temperature wave is propagated in a one-dimensional direction from the surface of the specimen to the inside, and from the amplitude ratio or phase difference between the temperature wave measured on the surface and the temperature wave measured inside. Then, the thermal diffusivity of the test specimen is obtained, and further, the thermal conductivity of the test specimen is obtained from the thermal diffusivity and the density and specific heat of the specimen measured separately (Patent Document 1, Patent Document 2, (See Non-Patent Document 1 and Non-Patent Document 2).
  • the temperature wave absorption surface is maintained in order to maintain the temperature of the temperature wave absorption surface at a predetermined constant value.
  • the output of the heater disposed opposite to the temperature wave absorption surface is increased to heat the temperature wave absorption surface, thereby increasing the temperature of the temperature wave absorption surface.
  • the heat from the heater is transmitted to the temperature wave absorption surface of the test body at once, so that the temperature of the temperature wave absorption surface rises rapidly and greatly exceeds the predetermined constant value. It may be difficult to maintain the temperature of the temperature wave absorption surface at the predetermined constant value.
  • the present invention has been made in view of the above problems, and an object thereof is to provide a method and an apparatus capable of measuring a thermal diffusivity with high accuracy.
  • a method for measuring thermal diffusivity by a periodic heating method in which a temperature wave is directed from a periodic heating surface of a specimen to a temperature wave absorbing surface. Measuring; a first temperature wave on the periodic heating surface; measuring a second temperature wave at a predetermined position inside the specimen between the periodic heating surface and the temperature wave absorbing surface; Obtaining a thermal diffusivity of the specimen from the amplitude ratio or phase difference between the first temperature wave and the second temperature wave, and at a position facing the temperature wave absorption surface, A temperature wave absorption heater having a heating element and a covering material covering the temperature wave absorption surface side of the heating element for maintaining the temperature at a predetermined constant value is disposed, and the temperature wave absorption surface and the temperature wave absorption Between the heater and the coating of the temperature wave absorption heater In a state where the arranging the high heat capacity member having a larger heat capacity heat capacity, and measuring the first temperature wave and the second temperature wave.
  • the high heat capacity member is disposed between the temperature wave absorption surface and the temperature wave absorption heater, and the temperature of the temperature wave absorption surface is maintained within a range of a predetermined value ⁇ 1 ° C.
  • the first temperature wave and the second temperature wave may be measured.
  • the high heat capacity member is disposed between the temperature wave absorption surface and the temperature wave absorption heater, and is formed between the temperature wave absorption surface and the temperature wave absorption heater. The first temperature wave and the second temperature wave may be measured in a state where a temperature sensor for measuring the temperature of the temperature wave absorbing surface is disposed in a gap surrounded by the members.
  • An apparatus for measuring thermal diffusivity by a periodic heating method, wherein the temperature from the periodic heating surface of the specimen to the temperature wave absorption surface is measured.
  • a periodic heater disposed opposite to the periodic heating surface for propagating waves; opposed to the temperature wave absorbing surface to maintain the temperature of the temperature wave absorbing surface of the specimen at a predetermined constant value
  • a temperature wave absorption heater having a heating element and a covering material covering the temperature wave absorption surface side of the heating element; a first temperature sensor for measuring a first temperature wave on the periodic heating surface;
  • a second temperature sensor for measuring a second temperature wave at a predetermined position inside the specimen between the periodic heating surface and the temperature wave absorption surface; a second temperature sensor for measuring a temperature of the temperature wave absorption surface;
  • the apparatus may include the third temperature sensor disposed between the temperature wave absorbing surface and the temperature wave absorbing heater and disposed in a gap surrounded by the high heat capacity member.
  • FIG. 1 is an explanatory diagram showing the principle of measuring the thermal diffusivity of a specimen by a periodic heating method.
  • FIG. 2 is an explanatory diagram showing an example of a temperature wave propagating through the test body in the periodic heating method.
  • FIG. 3 is an explanatory diagram showing a main configuration of an example of the present apparatus in a cross-sectional view.
  • This method is a method of measuring the thermal diffusivity by a periodic heating method, and propagating a temperature wave from the periodic heating surface 11 of the test body 10 toward the temperature wave absorbing surface 12; Measuring one temperature wave T1; measuring a second temperature wave T2 at a predetermined position 14 inside the test body 10 between the periodic heating surface 11 and the temperature wave absorbing surface 12; Obtaining the thermal diffusivity of the specimen 10 from the amplitude ratio or phase difference between the wave T1 and the second temperature wave T2.
  • the apparatus 100 is an apparatus for measuring the thermal diffusivity by a periodic heating method, and in order to propagate a temperature wave from the periodic heating surface 11 of the test body 10 toward the temperature wave absorbing surface 12, the periodic heating is performed.
  • Periodic heater 110 disposed opposite to surface 11; disposed to face temperature wave absorption surface 12 in order to maintain the temperature of temperature wave absorption surface 12 of test body 10 at a predetermined constant value.
  • a temperature wave is propagated in a one-dimensional direction (a direction indicated by an arrow D shown in FIG. 1) from the periodic heating surface 11 of the test body 10 to be measured on the periodic heating surface 11.
  • a temperature wave T1 temperature wave approximated by ⁇ 0 sin ( ⁇ t) shown in FIG. 2
  • a second temperature wave T2 ⁇ 1 sin ( ⁇ t + ⁇ shown in FIG. 2 measured at a predetermined position 14 inside the temperature wave T1.
  • the temperature T3 of the temperature wave absorption surface 12 opposite to the periodic heating surface 11 of the test body 10 (the surface of the test body 10 opposite to the periodic heating surface 11 in the one-dimensional direction in which the temperature wave propagates) is shown in FIG. As shown in FIG. 2 , it is assumed that the predetermined constant value ⁇ 2 is maintained.
  • the periodic heating method a one-dimensional heat flow from the periodic heating surface 11 of the test body 10 to the temperature wave absorption surface 12 is assumed.
  • the temperature of the origin (the temperature of the temperature wave absorption surface 12) is maintained at a predetermined constant value
  • ⁇ angular frequency [s ⁇ 1 ]
  • t time [s]
  • ⁇ an arbitrary phase [rad]).
  • the 1st temperature wave T1 is given to the periodic heating surface 11 of the test body 10, the 2nd temperature wave T2 reaches
  • k is represented by the following formula (III), and i is an imaginary unit.
  • ⁇ is an angular frequency represented by the following formula (IV), and ⁇ is a thermal diffusivity [m 2 / s].
  • f is the period [s].
  • the amplitude ratio A or the phase difference ⁇ obtained by comparing the first temperature wave T1 on the periodic heating surface 11 of the test body 10 and the second temperature wave T2 at the predetermined position 14 inside the test body 10. Based on the above, the thermal diffusivity ⁇ of the test body 10 is obtained.
  • the amplitude ratio A is substituted into the above formula (I) to obtain k, and then the value of k is substituted into the above formula (III), so that the thermal diffusivity ⁇ [m 2 / s] of the specimen 10 is obtained. Is obtained.
  • k is obtained by substituting the phase difference ⁇ [rad] into the above formula (II), the value of k is substituted into the above formula (III), and the thermal diffusivity ⁇ [m 2 / s] is obtained.
  • the thermal conductivity ⁇ [W / (m ⁇ K)] of the test body 10 is equal to the thermal diffusivity ⁇ [m 2 / s] obtained as described above and the test body 10 measured separately. It is obtained by substituting the density ⁇ [kg / m 3 ] and the specific heat c [J / (kg ⁇ K)] into the following equation (V).
  • the present apparatus 100 is preferably used in the present method for measuring the thermal diffusivity of the specimen 10 by the periodic heating method as described above.
  • the apparatus 100 includes a periodic heater 110 and a temperature wave absorption heater 120 as shown in FIG.
  • the periodic heater 110 heats the periodic heating surface 11 so as to give a temperature wave to the periodic heating surface 11 of the test body 10.
  • a DC power supply 200 and a function generator 210 are connected to the periodic heater 110.
  • the DC power source 200 supplies a DC current to the periodic heater 110.
  • the function generator 210 is a device that sets the period and amplitude of the temperature wave generated by the periodic heater 110.
  • the periodic heater 110 generates a temperature wave having a period and amplitude set by the function generator 210 via the DC power supply 200.
  • Temperature wave absorption heater 120 adjusts the heating of the temperature wave absorbing surface 12 so that the temperature of the temperature wave absorbing surface 12 of the specimen 10 is maintained at a predetermined constant value theta 2.
  • the apparatus 100 keeps the temperature of the side surface 13 of the test body 10 (the surface of the test body 10 connecting the periodic heating surface 11 and the temperature wave absorption surface 12 as shown in FIGS. 1 and 3) within a predetermined range.
  • it has the surrounding heater 130 arrange
  • the ambient heater 130 adjusts the heating of the side surface 13 so that the temperature of the side surface 13 of the test body 10 is maintained within a predetermined range.
  • the arrangement of the surrounding heater 130 is not particularly limited as long as the surrounding heater 130 is arranged to face the side surface 13. However, in the example illustrated in FIG. 3, the surrounding heater 130 is disposed on the side surface 13 through the gap G. Opposed to each other.
  • the gap G may be a space filled with gas (for example, air) or a vacuum.
  • the surrounding heater 130 may be, for example, a cylindrical heater (for example, a cylindrical heater) surrounding the side surface 13 of the test body 10.
  • the periodic heater 110, the temperature wave absorption heater 120, and the surrounding heater 130 are not particularly limited as long as they can heat the periodic heating surface 11, the temperature wave absorption surface 12, and the side surface 13 of the test body 10, respectively. It is a heater, a lamp heater or a laser irradiation device.
  • the apparatus 100 includes a first temperature sensor 310, a second temperature sensor 320, and a third temperature sensor 330. As shown in FIGS. 1 and 3, the first temperature sensor 310, the second temperature sensor 320, and the third temperature sensor 330 are preferably arranged linearly in a one-dimensional direction in which a temperature wave is propagated.
  • the first temperature sensor 310, the second temperature sensor 320, and the third temperature sensor 330 are preferably arranged on a virtual perpendicular drawn from the periodic heating surface 11 to the temperature wave absorption surface 12, for example. It is good also as arrange
  • the temperature wave absorption heater 120 Based on the measurement result of the temperature wave absorption surface 12 by the third temperature sensor 330, the temperature wave absorption heater 120 absorbs the temperature wave absorption so that the temperature of the temperature wave absorption surface 12 is maintained at a predetermined constant value. Adjust the heating of surface 12.
  • the apparatus 100 includes a fourth temperature sensor 340 for adjusting the heating by the ambient heater 130.
  • the fourth temperature sensor 340 is disposed in contact with the surface of the surrounding heater 130 facing the side surface 13 of the test body 10.
  • the ambient heater 130 adjusts the output of the ambient heater 130 (heating by the ambient heater 130) based on the temperature measurement result by the fourth temperature sensor 340.
  • the first temperature sensor 310, the second temperature sensor 320, the third temperature sensor 330, and the fourth temperature sensor 340 are, for example, a thermocouple or a platinum resistor.
  • the thickness of the first temperature sensor 310, the second temperature sensor 320, the third temperature sensor 330, and the fourth temperature sensor 340 may be, for example, one tenth or less of the thickness d of the test body 10. preferable.
  • the thickness of the casing Is a cylindrical case
  • the diameter of the case is preferably 1/10 or less of the thickness d of the test body 10.
  • the apparatus 100 includes a cooling device 140 disposed on the opposite side of the temperature wave absorption heater 120 from the test body 10.
  • the cooling device 140 cools the temperature wave absorption heater 120 so that the temperature wave is efficiently absorbed by the temperature wave absorption surface 12.
  • the cooling device 140 is a cooling tank containing a refrigerant, for example.
  • the apparatus 100 includes an auxiliary heater 150 disposed on the opposite side to the test body 10 of the periodic heater 110.
  • the auxiliary heater 150 keeps the periodic heater 110 warm so as to reduce heat loss from the periodic heater 110.
  • the auxiliary heater 150 is, for example, an electric heater.
  • the apparatus 100 includes a heat insulating material 160 disposed between the surrounding heater 130 and the auxiliary heater 150. This heat insulating material 160 ensures the thermal stability around the test body 10.
  • the apparatus 100 includes a heat insulating material 170 disposed around the cooling device 140. This heat insulating material 170 ensures thermal stability around the test body 10.
  • the measurement system described above is disposed on a metal plate 180 (for example, a stainless steel plate) and covered with a casing 190 (for example, a bell jar).
  • the test object 10 to be measured is not particularly limited as long as it is arranged between the periodic heater 110 and the temperature wave absorption heater 120.
  • the test body 10 may be selected from the group consisting of a heat insulating material, a laminated body of a heat insulating material and another member, plastic, metal, wood, gypsum board, and cement, for example.
  • the heat insulating material may be, for example, a fibrous heat insulating material, a porous heat insulating material, or a vacuum heat insulating material.
  • the fibrous heat insulating material is selected from the group consisting of, for example, rock wool heat insulating material, glass wool heat insulating material, alumina-based fiber heat insulating material (for example, alumina fiber wool heat insulating material), and alumina-silica-based fiber heat insulating material. Also good.
  • the porous heat insulating material is selected from the group consisting of, for example, an inorganic porous heat insulating material (for example, calcium silicate heat insulating material) or a foamed resin heat insulating material (for example, a foamed rubber molded body, a foamed polyurethane molded body, or a polystyrene foam molded body). It is also good to do.
  • an inorganic porous heat insulating material for example, calcium silicate heat insulating material
  • a foamed resin heat insulating material for example, a foamed rubber molded body, a foamed polyurethane molded body, or a polystyrene foam molded body. It is also good to do.
  • the laminated body of a heat insulating material and another member is good also as being a laminated body which has the said heat insulating material and the metal member and / or glass member which were laminated
  • the thermal diffusivity of the test specimen 10 exhibiting a relatively low thermal conductivity at a relatively high temperature can be measured with high accuracy. Therefore, for example, the test body 10 may have a thermal conductivity of 0.5 W / (m ⁇ K) or less at 1000 ° C., for example, and a heat of 0.3 W / (m ⁇ K) or less at 1000 ° C. It may have conductivity, or may have thermal conductivity of 0.2 W / (m ⁇ K) or less at 1000 ° C.
  • the lower limit value of the thermal conductivity of the test body 10 is not particularly limited.
  • the test body 10 may have a thermal conductivity of 0.01 W / (m ⁇ K) or more at 1000 ° C. .
  • test body 10 is not particularly limited as long as it is disposed between the periodic heater 110 and the temperature wave absorption heater 120, for example, a flat plate shape is preferable.
  • the periodic heating surface 11 and the temperature wave absorption surface 12 are arranged substantially in parallel.
  • the test body 10 may be composed of a single test body, or may be composed of two or more homogeneous test bodies stacked in the direction in which the temperature wave propagates. That is, the test body 10 may be, for example, one plate-like heat insulating material or a laminated body formed by laminating two or more same types of plate-like heat insulating materials.
  • test body 10 When the test body 10 is formed by stacking two or more test bodies, if a gap is formed between two adjacent test bodies, a gas (air) layer is formed between the two test bodies. The measurement result is affected by the thermal conductivity of the gas, and an error occurs.
  • the test body 10 is formed by laminating two or more test bodies, in a pair of the test bodies adjacent in the direction in which the temperature wave propagates, the surface of one test body and the other facing the surface For example, it is preferable not to form a gap of 0.5 mm or more between the surface of the test body.
  • a temperature wave is propagated from the periodic heating surface 11 of the test body 10 toward the temperature wave absorption surface 12. That is, a temperature wave having a predetermined period and a predetermined amplitude is generated by the periodic heater 110 facing the periodic heating surface 11. As a result, a temperature wave corresponding to the temperature wave generated by the periodic heater 110 is given to the periodic heating surface 11 of the test body 10.
  • the temperature wave given to the periodic heating surface 11 and propagating through the inside of the test body 10 reaches the temperature wave absorption surface 12 without being completely attenuated. That is, the periodic heater 110 gives a temperature wave that reaches the temperature wave absorbing surface 12 of the test body 10 to the periodic heating surface 11 of the test body 10.
  • the periodic heater 110 generates a temperature wave whose center of amplitude is a predetermined temperature.
  • the temperature at the center of the amplitude is not particularly limited.
  • the temperature may be a predetermined temperature within a range of ⁇ 190 ° C. to 1500 ° C., or may be a predetermined temperature within a range of 25 ° C. to 1500 ° C.
  • the temperature may be a predetermined temperature within a range of 700 ° C. to 1500 ° C., or may be a predetermined temperature within a range of 800 ° C. to 1500 ° C.
  • the thermal diffusivity of the specimen 10 can be measured with high accuracy even at such a relatively high temperature (for example, 700 ° C. to 1500 ° C. or 800 ° C. to 1500 ° C.).
  • the arithmetic average value of the center temperature of the amplitude of the temperature wave on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12 Is measured under such conditions that the temperature becomes 1000 ° C.
  • the gas around the test body 10 (the gas in contact with the side surface 13 of the test body 10 (the gas filled in the gap G)) is in contact with the gas.
  • the temperature of other members such as the surrounding heater 130 and the heat insulating materials 160 and 170 arranged to prevent heat loss periodically changes to form another temperature wave.
  • this other temperature wave penetrates into the inside of the test body 10 from the side surface 13 of the test body 10 and overlaps with the original temperature wave propagating from the periodic heating surface 11 toward the temperature wave absorption surface 12, and is measured. An error occurs.
  • the amplitude of the temperature wave generated by the periodic heater 110 is preferably a predetermined value within a range of 1 ° C. to 10 ° C., for example, and is preferably a predetermined value within a range of 1 ° C. to 5 ° C. More preferably, the predetermined value is in the range of 2 ° C. to 4 ° C.
  • the temperature wave generated by the periodic heater 110 preferably changes within a range of a predetermined temperature ⁇ 10 ° C., for example, preferably changes within a range of a predetermined temperature ⁇ 5 ° C., and the predetermined temperature ⁇ 2 ° C. It is preferable to change within the range.
  • the temperature wave can be properly propagated to the test body 10 and the measurement accuracy can be improved.
  • the temperature wave is periodically within a range of 1000 ⁇ 5 ° C. (995 ° C. to 1005 ° C.). Change.
  • the temperature of the test body 10 changes almost uniformly at all positions in the direction in which the temperature wave propagates in the test body 10, and the inside of the test body 10 Thus, a state in which the temperature wave propagates cannot be formed, and a measurement error occurs.
  • the period of the temperature wave is too short, while the temperature wave propagates through the inside of the test body 10, the temperature wave is completely attenuated and disappears on the way, resulting in a measurement error.
  • the period of the temperature wave generated by the periodic heater 110 is preferably a predetermined value within a range of 1 minute to 120 minutes, for example, and is preferably a predetermined value within a range of 15 minutes to 100 minutes. More preferably, the predetermined value is within a range of 30 minutes to 60 minutes.
  • the period of the temperature wave is within the appropriate range, the temperature wave can be appropriately propagated to the test body 10 and the measurement accuracy can be increased.
  • the temperature wave is distorted.
  • the amplitude ratio or phase difference between the first temperature wave T1 and the second temperature wave T2 at the predetermined position 14 inside the test body 10 cannot be measured accurately, resulting in a measurement error.
  • a temperature wave for one cycle each.
  • the difference between the average value of the center temperature of the amplitude and the average value of the center temperature of the amplitude of the temperature wave for the three cycles is preferably within ⁇ 2 ° C, more preferably within ⁇ 1 ° C. It is particularly preferable that the temperature is within ⁇ 0.2 ° C.
  • the average value of the center temperature of the amplitude of the temperature wave for each one cycle, the average value of the center temperature of the amplitude for the three cycles is preferably within ⁇ 2%, more preferably within ⁇ 0.5%, and particularly preferably within ⁇ 0.2%.
  • the temperature of the temperature wave absorption surface 12 is set to a predetermined constant value. Adjust.
  • the heating of the temperature wave absorption surface 12 by the temperature wave absorption heater 120 is adjusted so that the temperature of the temperature wave absorption surface 12 becomes a predetermined constant value.
  • the temperature wave absorption heater 120 adjusts the heating of the temperature wave absorption surface 12 based on the temperature measurement result of the temperature wave absorption surface 12 by the third temperature sensor 330.
  • the temperature wave absorption heater 120 increases its output to increase the heating of the temperature wave absorption surface 12 and absorb the temperature wave absorption. Increase the temperature of the surface 12.
  • the temperature wave absorption heater 120 decreases the output to weaken the heating of the temperature wave absorption surface 12, and the temperature wave absorption surface 12. Reduce the temperature.
  • weakening the heating of the temperature wave absorption surface 12 it is good also as operating the cooling device 140 mentioned above and cooling the temperature wave absorption heater 120.
  • the predetermined constant value at which the temperature of the temperature wave absorption surface 12 is to be adjusted is, for example, a temperature lower or higher than the central temperature of the amplitude of the temperature wave on the periodic heating surface 11 by a predetermined value in the range of 0 ° C. to 20 ° C.
  • the temperature may be lower or higher than the center temperature of the amplitude by a predetermined value within a range of 0 ° C. to 10 ° C., and may be 0 ° C. to 5 ° C. from the center temperature of the amplitude.
  • the temperature may be lower or higher by a predetermined value within the range.
  • the predetermined constant value to which the temperature of the temperature wave absorption surface 12 should be adjusted may be, for example, a predetermined constant value within the range of the center temperature ⁇ 20 ° C. of the temperature wave amplitude on the periodic heating surface 11.
  • it may be a predetermined constant value within the range of the center temperature ⁇ 10 ° C., or may be a predetermined constant value within the range of the center temperature ⁇ 5 ° C.
  • the thermal diffusivity ⁇ is obtained using the above formulas (I) to (III).
  • This measurement principle is based on the condition that the temperature of one surface (periodic heating surface 11) of the test body 10 is periodically changed and the temperature of the opposite surface (temperature wave absorption surface 12) is kept constant.
  • the solution obtained by solving the conduction equation is used, in practice, it is impossible to make the temperature of the temperature wave absorbing surface 12 completely constant. For this reason, the degree to which the temperature fluctuation on the temperature wave absorption surface 12 can be suppressed greatly affects the measurement accuracy.
  • the temperature of the temperature wave absorbing surface 12 is preferably maintained within a predetermined constant value ⁇ 0.5 ° C., and more preferably maintained within a predetermined constant value ⁇ 0.2 ° C. It is particularly preferable to maintain within a range of a predetermined constant value ⁇ 0.05 ° C.
  • the temperature wave propagated from the periodic heating surface 11 is not efficiently absorbed by the temperature wave absorption surface 12 (disappearance). Measurement error may occur.
  • the temperature wave absorption surface 12 and the temperature wave absorption heater 120 may be brought into contact with each other.
  • the 3rd temperature sensor 330 for measuring the temperature of the temperature wave absorption surface 12 is good also as arrange
  • the third temperature sensor 330 may be arranged without contacting the temperature wave absorption heater 120.
  • the temperature of the side surface 13 of the test body 10 is set within a predetermined range. Adjust.
  • the heating of the side surface 13 by the surrounding heater 130 is adjusted so that the temperature of the side surface 13 of the test body 10 is within a predetermined range.
  • the ambient heater 130 adjusts the heating of the side surface 13 of the test body 10 based on the result of the temperature measured by the fourth sensor 340.
  • the ambient heater 130 increases its output to increase the heating of the side surface 13 and increase the temperature of the side surface 13. In addition, when the measured temperature exceeds the predetermined range, the ambient heater 130 decreases the output to weaken the heating of the side surface 13 and decrease the temperature of the side surface 13.
  • the predetermined range in which the temperature of the side surface 13 of the test body 10 should be adjusted is, for example, the arithmetic average value ⁇ 50 ° C. between the center temperature of the temperature wave amplitude on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12.
  • the arithmetic average value ⁇ 20 ° C. is more preferable, and the arithmetic average value ⁇ 5 ° C. is particularly preferable.
  • the temperature may be adjusted to be within a predetermined range.
  • the temperature of the surrounding heater 130 is maintained within a predetermined range, that is, a predetermined constant value and the vicinity thereof.
  • the fourth temperature sensor 340 is arranged on the surface of the surrounding heater 340 facing the side surface 13 of the test body 10, and based on the temperature measurement result by the fourth temperature sensor 340.
  • the output of the surrounding heater 130 (heating by the surrounding heater 130) is adjusted so that the measured temperature is within a predetermined range.
  • the predetermined range in which the temperature of the surrounding heater 130 should be adjusted is, for example, a range of ⁇ 50 ° C. arithmetic average value between the center temperature of the temperature wave amplitude on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12.
  • the arithmetic average value is more preferably within a range of ⁇ 20 ° C., and the arithmetic average value is preferably within a range of ⁇ 5 ° C.
  • a first temperature wave T1 on the periodic heating surface 11 of the test body 10 and a second temperature wave T2 at a predetermined position 14 inside the test body 10 are measured. That is, the temperature wave T ⁇ b> 1 applied from the periodic heater 110 to the periodic heating surface 11 is measured by the first temperature sensor 310 and transmitted from the periodic heating surface 11 to the predetermined position 14 inside the test body 10. The temperature wave T ⁇ b> 2 is measured by the second temperature sensor 320.
  • the apparatus 100 includes a heating element 121 and a covering material 122 that covers the temperature wave absorbing surface 12 side of the heating element 121. And a high heat capacity member 400 having a heat capacity larger than the heat capacity of the covering material 122 of the temperature wave absorption heater 120 disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120.
  • the heating element 121 and the heating element 121 for maintaining the temperature of the temperature wave absorption surface 12 at a predetermined constant value at a position facing the temperature wave absorption surface 12 are provided.
  • a temperature wave absorption heater 120 having a covering material 122 covering the temperature wave absorption surface 12 side is disposed, and the temperature wave absorption heater 120 is interposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120.
  • the said high thermal capacity member 400 having a larger heat capacity than the heat capacity of the coating material 122 is to measure the first temperature wave T1 and the second temperature wave T2.
  • the output of the temperature wave absorption heater 120 is changed quickly and frequently.
  • the heat capacity of the covering material 122 that covers the temperature wave absorbing surface 12 side of the heating element 121 of the temperature wave absorbing heater 120 is small, the output of the temperature wave absorbing heater 120 is largely changed to thereby change the covering.
  • the temperature of the material 122 (the temperature of the surface of the temperature wave absorption heater 120 facing the temperature wave absorption surface 12) and the temperature of the temperature wave absorption surface 12 change rapidly, and the temperature of the temperature wave absorption surface 12 is changed. It becomes difficult to adjust to a predetermined constant value.
  • the high heat capacity member 400 having a heat capacity larger than the heat capacity of the covering 122 of the temperature wave absorption heater 120 is disposed between the temperature wave absorption surface 12 of the test body 10 and the temperature wave absorption heater 120. To do.
  • the temperature is increased. It is possible to effectively prevent a sudden change in the temperature of the temperature wave absorption surface 12 due to a large change in the output of the wave absorption heater 120. Therefore, the temperature of the temperature wave absorption surface 12 of the test body 10 can be maintained at a predetermined constant value or the vicinity thereof, and the thermal diffusivity of the test body 10 can be measured with high accuracy.
  • the high heat capacity member 400 is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, and the temperature of the temperature wave absorption surface 12 is set to a predetermined value ⁇ 1 ° C.
  • the first temperature wave T1 and the second temperature wave T2 are measured while being maintained within the range.
  • the temperature of the temperature wave absorbing surface 12 is preferably maintained within a range of a predetermined value ⁇ 0.5 ° C, and more preferably maintained within a range of a predetermined value ⁇ 0.1 ° C.
  • the heat capacity of the high heat capacity member 400 is not particularly limited as long as it is larger than the heat capacity of the covering material 122 of the temperature wave absorption heater 120.
  • the heat capacity of the high heat capacity member 400 is preferably twice or more than the heat capacity of the covering material 122. More preferably.
  • the temperature wave absorption heater 120 is not particularly limited as long as it is a heater having a heating element 121 and a covering material 122, but is preferably an electric heater, for example.
  • the heating element 121 is a heating wire such as a nichrome wire, for example.
  • the covering material 122 is, for example, an inorganic material such as alumina or a metal material such as stainless steel.
  • the heat capacity of the high heat capacity member 400 may be, for example, larger than the heat capacity of the covering material 122 of the temperature wave absorption heater 120 and 50 J / K or more, preferably 100 J / K or more. In this case, the thermal diffusivity of the specimen 10 can be measured with higher accuracy.
  • the third temperature It is not easy to appropriately control the output of the temperature wave absorption heater 120 based on the temperature measured by the sensor 330 and maintain the temperature of the temperature wave absorption surface 12 at a predetermined constant value.
  • a high heat capacity member 400 having a relatively large heat capacity 50 J / K or more or 100 J / K or more
  • the temperature wave absorption surface 12 is provided.
  • the reached temperature wave can be effectively attenuated and the amplitude thereof can be effectively reduced, and it becomes easier to adjust the temperature of the temperature wave absorption surface 12 to a predetermined constant value.
  • the shape of the high heat capacity member 400 is not particularly limited as long as the high heat capacity member 400 can be disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120 of the test body 10.
  • a plate shape is preferable. .
  • the material constituting the high heat capacity member 400 is not particularly limited as long as it has a relatively large heat capacity as described above.
  • inorganic materials such as ceramics (for example, alumina), cement, glass, stainless steel, etc. It may be one or more selected from the group consisting of organic materials such as metal materials and plastics.
  • the high heat capacity member 400 made of a heat-resistant material that can be used at the measurement temperature. Is used. Specifically, in this case, it is preferable to use a high heat capacity member 400 made of an inorganic material or a metal material.
  • the third temperature sensor 330 may be arranged between the temperature wave absorption heater 120 and the temperature wave absorption surface 12 without contacting the temperature wave absorption surface heater 120. In this case, the third temperature sensor 330 may be disposed in contact with the high heat capacity member 400 without contacting the temperature wave absorbing heater 120. In these cases, based on the measurement result of the temperature of the high heat capacity member 400 by the third temperature sensor 330 or the temperature corresponding to the temperature, the temperature of the temperature wave absorbing surface 12 is set to a predetermined constant value or the vicinity thereof. Can be adjusted effectively.
  • the apparatus 100 includes a third temperature sensor 330 that is disposed in a gap 500 that is formed between the temperature wave absorbing surface 12 and the temperature wave absorbing heater 120 and surrounded by the high heat capacity member 400.
  • the high heat capacity member 400 is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, and the temperature wave absorption surface 12, the temperature wave absorption heater 120,
  • the first temperature wave It is good also as measuring T1 and 2nd temperature wave T2.
  • the temperature of the temperature wave absorption surface 12 is more effectively set to a predetermined constant value or the vicinity thereof. Can be adjusted.
  • the gap 500 in which the third temperature sensor 330 is disposed is not particularly limited as long as a space capable of accommodating the third temperature sensor 330 is formed.
  • the gap 500 formed on the surface of the high heat capacity member 400 It is good also as a notch or a groove
  • the third temperature sensor 330 may be arranged without contacting the temperature wave absorption surface heater 120.
  • the third temperature sensor 330 may be disposed in the gap 500 in contact with the high heat capacity member 400 without contacting the temperature wave absorbing heater 120.
  • the temperature of the temperature wave absorbing surface 12 is more effectively set to a predetermined constant value or the vicinity thereof. Can be adjusted to.
  • the cycle is relatively from the periodic heating surface 11 of the test body 10 toward the temperature wave absorption surface 12.
  • the thermal diffusivity of the specimen 10 may be measured by propagating a short temperature wave (for example, 20 minutes or less, more specifically, 1 minute to 20 minutes).
  • the effect of disposing the high heat capacity member 400 is particularly remarkable when the period of the temperature wave is relatively short.
  • the heat of the test body 10 at a relatively high temperature eg, 700 ° C. or more, or 800 ° C. or more.
  • the diffusivity may be measured.
  • the effect of disposing the high heat capacity member 400 is particularly remarkable when the measurement temperature is relatively high.
  • the amplitude of the temperature wave generated by the periodic heater 110 that applies a temperature wave to the periodic heating surface 11 of the test body 10 is within a predetermined value ⁇ 10 ° C., and is in contact with the periodic heater 110.
  • ⁇ 10 ° C. a predetermined value
  • the area of the surface of the periodic heater 110 facing the periodic heating surface 11 of the test body 10 is within the range of ⁇ 20% of the area of the periodic heating surface 11. It is preferable that
  • the emissivity of the casing 190 that houses the measurement unit including the test body 10, the periodic heater 110, the temperature wave absorption heater 120, the auxiliary heater 150, the heater surrounding the measurement unit, the wall material, etc. is 0.1 or more. These heat capacities are preferably 50 J / K or more.
  • FIG. 4 shows the temperature wave when the high heat capacity member 400 is arranged between the temperature wave absorption surface 12 of the test body 10 and the temperature wave absorption heater 120 and when the high heat capacity member 400 is not arranged. The result of having examined theoretically the amplitude of the temperature wave in the absorption surface 12 is shown.
  • the density of the high heat capacity member 400 is 3800 (kg / m 3 )
  • the specific heat is 1000 (J / kg ⁇ K)
  • the horizontal axis indicates the period (minute) of the temperature wave
  • the vertical axis indicates the amplitude ⁇ 0 of the temperature wave reaching the temperature wave absorption surface 12 from the periodic heating surface 11 of the test body 10 and the high heat capacity plate 400.
  • the temperature amplitude ⁇ or the ratio ( ⁇ / ⁇ 0 ) of the temperature amplitude ⁇ of the air layer between the temperature wave absorbing surface 12 and the temperature wave absorbing heater 120 is shown.
  • the result of solving the heat conduction equation on the assumption that heat flows from the test body 10 into the high heat capacity member 400 in a trigonometric function is indicated by a solid line
  • the high heat capacity member 400 is The result when not arranged is shown by a broken line.
  • the specific heat of the high heat capacity member 400 is C p
  • the density is ⁇
  • the volume is v
  • the heat transfer rate from the test body 10 to the high heat capacity member 400 is ⁇
  • the heat transfer area at that time is S
  • the test body 10 When the temperature wave entering the high heat capacity member 400 from ⁇ s and the temperature of the high heat capacity member 400 or the air layer as ⁇ , the thermal conductivity equation represented by the following formula (VI) is established.
  • the amplitude ratio ( ⁇ / ⁇ 0 ) when the temperature wave propagates from the test body 10 to the high heat capacity member 400 or the air layer can be obtained using the above formula (XVII).
  • the output of the temperature wave absorption heater 120 must be controlled at a short time interval. For this reason, when the temperature wave reaches the temperature wave absorption surface 12 without being attenuated, the temperature wave absorption heater 120 rapidly increases the output in a short time. As a result, the temperature of the temperature wave absorption surface 12 overshoots. And it becomes difficult to maintain the temperature in the said temperature wave absorption surface 12 at a predetermined fixed value.
  • the temperature at the temperature wave absorbing surface 12 can be easily maintained at a predetermined constant value even in the measurement using the temperature wave with a short cycle by arranging the high heat capacity member 400.
  • the thermal diffusivity of the test specimen 10 was measured by this method using the apparatus 100 having the high heat capacity member 400, and the thermal conductivity of the test specimen 10 was obtained from the thermal diffusivity.
  • the high heat capacity member 400 two alumina flat plates (73 mm ⁇ 100 mm, thickness 30 mm) having a heat capacity (about 170 J / K) that is about 10 times the heat capacity of the covering material 122 of the temperature wave absorption heater 120 were used. .
  • an electric heater having a heating element 121 made of a metal heating wire and a ceramic covering material 122 that covers the heating element 121 is used. did.
  • the diameter is one tenth or less of the thickness of the test body 10 and the thickness of the high heat capacity member 400.
  • a high heat capacity member 400 made of two alumina plates is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120 with a gap 500 therebetween.
  • a third temperature sensor 330 made of a thermocouple was disposed in the gap 500 sandwiched between two alumina plates.
  • a groove is formed in the periodic heating surface 11 and the first temperature sensor 310 is arranged in the groove, and between the periodic heating surface 11 and the periodic heater 110 (the first heater). Between the temperature sensor 310 and the periodical heater 110), an inorganic fiber fleece was disposed.
  • the ambient heater 130 was used with its output limited in advance to a predetermined value ⁇ 0.05%. Further, the temperature wave measured at the periodic heating surface 11 and the predetermined position 14 inside the test body 10 is obtained by approximating the measured value for one period to a trigonometric function by the least square method, and obtaining the approximation. From the phase difference of the temperature wave, the thermal diffusivity of the specimen 10 was measured.
  • an alumina-silica fiber heat insulating material 150 mm ⁇ 100 mm, thickness 30 mm was used as the test body 10, and the test body 10 was tested at 100 ° C., 200 ° C., 400 ° C., 600 ° C., 800 ° C., 1000
  • the thermal diffusivity was measured at 1,200, 1,400, and 1500 ° C., and the thermal conductivity was determined from the thermal diffusivity.
  • the amplitude of the temperature wave generated by the periodic heater 110 was 3 ° C., and the period was 60 minutes.
  • the temperature of the temperature wave absorbing surface 12 of the test body 10 was maintained within a range of a predetermined value ⁇ 0.05 ° C.
  • the average value of the center temperature of the amplitude of the temperature wave for one period and the average of the center temperature of the amplitude of the temperature wave for the three periods was within ⁇ 2 ° C.
  • the thermal conductivity of the specimen 10 was also measured by the GHP method.
  • test body 10 two fiber reinforced cement plates (150 mm ⁇ 100 mm, thickness 20 mm) are used as the test body 10, the thermal diffusivities of the test body 10 at 100 ° C., 300 ° C., and 500 ° C. are measured, and the thermal diffusivity is measured. From this, the thermal conductivity was determined.
  • the amplitude of the temperature wave generated by the periodic heater 110 was 2 ° C., and the period was 60 minutes.
  • the temperature of the temperature wave absorbing surface 12 of the test body 10 was maintained within a range of a predetermined value ⁇ 0.05 ° C.
  • the average value of the center temperature of the amplitude of the temperature wave for one period and the average of the center temperature of the amplitude of the temperature wave for the three periods was within ⁇ 2 ° C.
  • the thermal conductivity of the specimen 10 was also measured by the GHP method.
  • a stainless steel (SUS) plate 150 mm ⁇ 100 mm, thickness 50 mm was used as the test body 10, the thermal diffusivity of the test body 10 at 110 ° C. was measured, and the thermal conductivity was obtained from the thermal diffusivity. .
  • the amplitude of the temperature wave generated by the periodic heater 110 was 5 ° C., and the period was 5 minutes.
  • the temperature of the temperature wave absorbing surface 12 of the test body 10 was maintained within a range of a predetermined value ⁇ 0.05 ° C.
  • the average value of the center temperature of the amplitude of the temperature wave for one period and the average of the center temperature of the amplitude of the temperature wave for the three periods was within ⁇ 2 ° C.
  • FIG. 5, FIG. 6 and FIG. 7 show the results of measuring the thermal conductivity of the alumina-silica fiber heat insulating material, the fiber reinforced cement board and the SUS board, respectively.
  • the horizontal axis represents the temperature (° C.) at which the thermal conductivity is measured (the arithmetic average value of the center temperature of the temperature wave amplitude on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12).
  • the vertical axis indicates the thermal conductivity (W / (m ⁇ K)) measured at each temperature.
  • circles indicate the results measured by this method using the periodic heating method
  • square marks indicate the results measured by the GHP method
  • circles indicate the results measured by this method using the periodic heating method
  • solid lines indicate literature values (new thermophysical handbook, edited by the Japan Society for Thermophysical Properties, p. 213 (March 25, 2008, 1st Edition). Issue)).
  • the measurement result by this method using the present apparatus 100 almost coincided with the measurement result by the GHP method. Furthermore, as shown in FIG. 7, the measurement result by this method using this apparatus 100 was in agreement with the literature value. That is, according to the method using the apparatus 100, it was confirmed that the thermal diffusivity and the thermal conductivity can be measured with high accuracy in a wide temperature range.

Abstract

This invention provides a method and a device that make it possible to measure thermal diffusivity with high precision. This method for measuring thermal diffusivity via cyclic heating includes the following: causing thermal waves to propagate from a cyclic-heating surface (11) of a specimen (10) towards a thermal-wave absorption surface (12) thereof; measuring a first thermal wave at said cyclic-heating surface; measuring a second thermal wave at a prescribed position (14) inside the specimen between the cyclic-heating surface and the thermal-wave absorption surface; and obtaining the thermal diffusivity of the specimen from the amplitude ratio or phase difference between the first thermal wave and the second thermal wave. A thermal-wave-absorbing heater (120) for keeping the thermal-wave absorption surface at a prescribed constant temperature is positioned opposite said thermal-wave absorption surface, said thermal-wave-absorbing heater (120) having a heating element (121) and a covering material (122) that covers the side of said heating element that faces the thermal-wave absorption surface. The first and second thermal waves are measured with a high-heat-capacity member (400) positioned between the thermal-wave absorption surface and the thermal-wave-absorbing heater, said high-heat-capacity member (400) having a higher heat capacity than the covering material of the thermal-wave-absorbing heater.

Description

熱拡散率を測定する方法及び装置Method and apparatus for measuring thermal diffusivity
　本発明は、熱拡散率を測定する方法及び装置に関し、特に、周期加熱法により熱拡散率を測定する方法及び装置に関する。 The present invention relates to a method and apparatus for measuring thermal diffusivity, and more particularly to a method and apparatus for measuring thermal diffusivity by a periodic heating method.
　試験体の熱伝導率を測定するための方法としては、定常法である保護熱板（Ｇｕａｒｄｅｄ　Ｈｏｔ　Ｐｌａｔｅ：ＧＨＰ）法や熱流計法の他に、非定常法である周期加熱法がある。 As a method for measuring the thermal conductivity of the test specimen, there is a periodic heating method which is an unsteady method in addition to a guarded hot plate (GHP) method which is a steady method and a heat flow meter method.
　周期加熱法においては、試験体の表面から内部に、一次元方向に温度波を伝播させ、当該表面で測定される温度波と、当該内部で測定される温度波との振幅比又は位相差から、当該試験体の熱拡散率を求め、さらに、当該熱拡散率と、別途測定された当該試験体の密度及び比熱とから当該試験体の熱伝導率を求める（特許文献１、特許文献２、非特許文献１、非特許文献２参照）。 In the periodic heating method, a temperature wave is propagated in a one-dimensional direction from the surface of the specimen to the inside, and from the amplitude ratio or phase difference between the temperature wave measured on the surface and the temperature wave measured inside. Then, the thermal diffusivity of the test specimen is obtained, and further, the thermal conductivity of the test specimen is obtained from the thermal diffusivity and the density and specific heat of the specimen measured separately (Patent Document 1, Patent Document 2, (See Non-Patent Document 1 and Non-Patent Document 2).
特開２００５－２２７０１０号公報JP 2005-227010 A 特開２０００－０５５８４６号公報JP 2000-055846 A
　しかしながら、従来の周期加熱法においては、十分に高い精度で熱拡散率を測定することが難しかった。 However, in the conventional periodic heating method, it has been difficult to measure the thermal diffusivity with sufficiently high accuracy.
　すなわち、試験体の周期加熱面から、反対側の温度波吸収面に向けて温度波を伝播させる際、当該温度波吸収面の温度を所定の一定値に維持するために、当該温度波吸収面の温度が当該所定の一定値を下回ると、当該温度波吸収面に対向して配置されたヒータの出力を上げて当該温度波吸収面を加熱し、当該温度波吸収面の温度を上昇させる。 That is, when the temperature wave is propagated from the periodic heating surface of the test body toward the opposite temperature wave absorption surface, the temperature wave absorption surface is maintained in order to maintain the temperature of the temperature wave absorption surface at a predetermined constant value. When the temperature falls below the predetermined constant value, the output of the heater disposed opposite to the temperature wave absorption surface is increased to heat the temperature wave absorption surface, thereby increasing the temperature of the temperature wave absorption surface.
　しかしながら、従来、試験体の温度波吸収面にヒータからの熱が一気に伝わることにより、当該温度波吸収面の温度が急激に上昇して、上記所定の一定値を大幅に上回り、その結果、当該温度波吸収面の温度を当該所定の一定値に維持することが難しくなることがあった。 However, conventionally, the heat from the heater is transmitted to the temperature wave absorption surface of the test body at once, so that the temperature of the temperature wave absorption surface rises rapidly and greatly exceeds the predetermined constant value. It may be difficult to maintain the temperature of the temperature wave absorption surface at the predetermined constant value.
　本発明は、上記課題に鑑みて為されたものであって、高い精度で熱拡散率を測定することができる方法及び装置を提供することをその目的の一つとする。 The present invention has been made in view of the above problems, and an object thereof is to provide a method and an apparatus capable of measuring a thermal diffusivity with high accuracy.
　上記課題を解決するための本発明の一実施形態に係る方法は、周期加熱法により熱拡散率を測定する方法であって、試験体の周期加熱面から温度波吸収面に向けて温度波を伝播させること；前記周期加熱面における第一温度波を測定すること；前記周期加熱面と前記温度波吸収面との間の前記試験体の内部の所定位置における第二温度波を測定すること；前記第一温度波と前記第二温度波との振幅比又は位相差から前記試験体の熱拡散率を得ること；を含み、前記温度波吸収面と対向する位置に、前記温度波吸収面の温度を所定の一定値に維持するための、発熱体と前記発熱体の前記温度波吸収面側を覆う被覆材とを有する温度波吸収ヒータを配置し、前記温度波吸収面と前記温度波吸収ヒータとの間に、前記温度波吸収ヒータの前記被覆材の熱容量より大きい熱容量を有する高熱容量部材を配置した状態で、前記第一温度波及び前記第二温度波を測定することを特徴とする。本発明によれば、高い精度で熱拡散率を測定する方法を提供することができる。 A method according to an embodiment of the present invention for solving the above-described problem is a method for measuring thermal diffusivity by a periodic heating method, in which a temperature wave is directed from a periodic heating surface of a specimen to a temperature wave absorbing surface. Measuring; a first temperature wave on the periodic heating surface; measuring a second temperature wave at a predetermined position inside the specimen between the periodic heating surface and the temperature wave absorbing surface; Obtaining a thermal diffusivity of the specimen from the amplitude ratio or phase difference between the first temperature wave and the second temperature wave, and at a position facing the temperature wave absorption surface, A temperature wave absorption heater having a heating element and a covering material covering the temperature wave absorption surface side of the heating element for maintaining the temperature at a predetermined constant value is disposed, and the temperature wave absorption surface and the temperature wave absorption Between the heater and the coating of the temperature wave absorption heater In a state where the arranging the high heat capacity member having a larger heat capacity heat capacity, and measuring the first temperature wave and the second temperature wave. The present invention can provide a method for measuring the thermal diffusivity with high accuracy.
　また、前記方法において、前記温度波吸収面と前記温度波吸収ヒータとの間に前記高熱容量部材を配置して、前記温度波吸収面の温度を所定値±１℃の範囲内に維持した状態で、前記第一温度波及び前記第二温度波を測定することとしてもよい。また、前記方法において、前記温度波吸収面と前記温度波吸収ヒータとの間に前記高熱容量部材を配置するとともに、前記温度波吸収面と前記温度波吸収ヒータとの間に形成され前記高熱容量部材で囲まれた隙間に、前記温度波吸収面の温度を測定するための温度センサを配置した状態で、前記第一温度波及び前記第二温度波を測定することとしてもよい。 Further, in the method, the high heat capacity member is disposed between the temperature wave absorption surface and the temperature wave absorption heater, and the temperature of the temperature wave absorption surface is maintained within a range of a predetermined value ± 1 ° C. Thus, the first temperature wave and the second temperature wave may be measured. Further, in the method, the high heat capacity member is disposed between the temperature wave absorption surface and the temperature wave absorption heater, and is formed between the temperature wave absorption surface and the temperature wave absorption heater. The first temperature wave and the second temperature wave may be measured in a state where a temperature sensor for measuring the temperature of the temperature wave absorbing surface is disposed in a gap surrounded by the members.
　上記課題を解決するための本発明の一実施形態に係る装置は、周期加熱法により熱拡散率を測定するための装置であって、試験体の周期加熱面から温度波吸収面に向けて温度波を伝播させるために、前記周期加熱面に対向して配置される周期加熱ヒータ；前記試験体の前記温度波吸収面の温度を所定の一定値に維持するために前記温度波吸収面に対向して配置される、発熱体と前記発熱体の前記温度波吸収面側を覆う被覆材とを有する温度波吸収ヒータ；前記周期加熱面における第一温度波を測定するための第一温度センサ；前記周期加熱面と前記温度波吸収面との間の前記試験体の内部の所定位置における第二温度波を測定するための第二温度センサ；前記温度波吸収面の温度を測定するための第三温度センサ；及び前記試験体の前記温度波吸収面と前記温度波吸収ヒータとの間に配置される、前記温度波吸収ヒータの前記被覆材の熱容量より大きい熱容量を有する高熱容量部材；を有することを特徴とする。本発明によれば、高い精度で熱拡散率を測定する装置を提供することができる。 An apparatus according to an embodiment of the present invention for solving the above-described problem is an apparatus for measuring thermal diffusivity by a periodic heating method, wherein the temperature from the periodic heating surface of the specimen to the temperature wave absorption surface is measured. A periodic heater disposed opposite to the periodic heating surface for propagating waves; opposed to the temperature wave absorbing surface to maintain the temperature of the temperature wave absorbing surface of the specimen at a predetermined constant value A temperature wave absorption heater having a heating element and a covering material covering the temperature wave absorption surface side of the heating element; a first temperature sensor for measuring a first temperature wave on the periodic heating surface; A second temperature sensor for measuring a second temperature wave at a predetermined position inside the specimen between the periodic heating surface and the temperature wave absorption surface; a second temperature sensor for measuring a temperature of the temperature wave absorption surface; Three temperature sensors; and the temperature of the specimen It characterized by having a; is disposed between the wave absorbing surface and the temperature wave absorption heater, high heat capacity member having a larger heat capacity than the heat capacity of the coating material of the temperature wave absorption heater. ADVANTAGE OF THE INVENTION According to this invention, the apparatus which measures a thermal diffusivity with high precision can be provided.
　また、前記装置は、前記温度波吸収面と前記温度波吸収ヒータとの間に形成され前記高熱容量部材で囲まれた隙間に配置された前記第三温度センサを有することとしてもよい。 The apparatus may include the third temperature sensor disposed between the temperature wave absorbing surface and the temperature wave absorbing heater and disposed in a gap surrounded by the high heat capacity member.
　本発明によれば、高い精度で熱拡散率を測定する方法及び装置を提供することができる。 According to the present invention, it is possible to provide a method and apparatus for measuring thermal diffusivity with high accuracy.
周期加熱法により試験体の熱拡散率を測定する原理を示す説明図である。It is explanatory drawing which shows the principle which measures the thermal diffusivity of a test body by a periodic heating method. 周期加熱法において試験体を伝播する温度波の例を示す説明図である。It is explanatory drawing which shows the example of the temperature wave which propagates a test body in a periodic heating method. 本実施形態に係る熱拡散率測定装置の一例について、その主な構成を断面視で示す説明図である。It is explanatory drawing which shows the main structure by sectional view about an example of the thermal diffusivity measuring apparatus which concerns on this embodiment. 本実施形態に係る実施例１において振幅比を計算した結果を示す説明図である。It is explanatory drawing which shows the result of having calculated the amplitude ratio in Example 1 which concerns on this embodiment. 本実施形態に係る実施例２において熱伝導率を測定した結果の一例を示す説明図である。It is explanatory drawing which shows an example of the result of having measured thermal conductivity in Example 2 which concerns on this embodiment. 本実施形態に係る実施例２において熱伝導率を測定した結果の他の例を示す説明図である。It is explanatory drawing which shows the other example of the result of having measured thermal conductivity in Example 2 which concerns on this embodiment. 本実施形態に係る実施例２において熱伝導率を測定した結果のさらに他の例を示す説明図である。It is explanatory drawing which shows the further another example of the result of having measured thermal conductivity in Example 2 which concerns on this embodiment.
　以下に、本発明の一実施形態について説明する。なお、本発明は、本実施形態に限られるものではない。 Hereinafter, an embodiment of the present invention will be described. Note that the present invention is not limited to this embodiment.
　まず、本実施形態に係る熱拡散率測定方法（本方法）及び熱拡散率測定装置（本装置）の概要について説明する。図１は、周期加熱法により試験体の熱拡散率を測定する原理を示す説明図である。図２は、周期加熱法において試験体を伝播する温度波の一例を示す説明図である。図３は、本装置の一例の主な構成を断面視で示す説明図である。 First, an outline of a thermal diffusivity measuring method (this method) and a thermal diffusivity measuring apparatus (this device) according to the present embodiment will be described. FIG. 1 is an explanatory diagram showing the principle of measuring the thermal diffusivity of a specimen by a periodic heating method. FIG. 2 is an explanatory diagram showing an example of a temperature wave propagating through the test body in the periodic heating method. FIG. 3 is an explanatory diagram showing a main configuration of an example of the present apparatus in a cross-sectional view.
　本方法は、周期加熱法により熱拡散率を測定する方法であって、試験体１０の周期加熱面１１から温度波吸収面１２に向けて温度波を伝播させること；当該周期加熱面１１における第一温度波Ｔ１を測定すること；当該周期加熱面１１と当該温度波吸収面１２との間の当該試験体１０の内部の所定位置１４における第二温度波Ｔ２を測定すること；当該第一温度波Ｔ１と当該第二温度波Ｔ２との振幅比又は位相差から当該試験体１０の熱拡散率を得ること；を含む。 This method is a method of measuring the thermal diffusivity by a periodic heating method, and propagating a temperature wave from the periodic heating surface 11 of the test body 10 toward the temperature wave absorbing surface 12; Measuring one temperature wave T1; measuring a second temperature wave T2 at a predetermined position 14 inside the test body 10 between the periodic heating surface 11 and the temperature wave absorbing surface 12; Obtaining the thermal diffusivity of the specimen 10 from the amplitude ratio or phase difference between the wave T1 and the second temperature wave T2.
　本装置１００は、周期加熱法により熱拡散率を測定するための装置であって、試験体１０の周期加熱面１１から温度波吸収面１２に向けて温度波を伝播させるために、当該周期加熱面１１に対向して配置される周期加熱ヒータ１１０；当該試験体１０の当該温度波吸収面１２の温度を所定の一定値に維持するために、当該温度波吸収面１２に対向して配置される温度波吸収ヒータ１２０；当該周期加熱面１１における第一温度波Ｔ１を測定するための第一温度センサ３１０；当該周期加熱面１１と当該温度波吸収面１２との間の当該試験体１０の内部の所定位置１４における第二温度波Ｔ２を測定するための第二温度センサ３２０；当該温度波吸収面１２の温度を測定するための第三温度センサ３３０；を有する。 The apparatus 100 is an apparatus for measuring the thermal diffusivity by a periodic heating method, and in order to propagate a temperature wave from the periodic heating surface 11 of the test body 10 toward the temperature wave absorbing surface 12, the periodic heating is performed. Periodic heater 110 disposed opposite to surface 11; disposed to face temperature wave absorption surface 12 in order to maintain the temperature of temperature wave absorption surface 12 of test body 10 at a predetermined constant value. Temperature wave absorption heater 120; first temperature sensor 310 for measuring the first temperature wave T1 on the periodic heating surface 11; the test body 10 between the periodic heating surface 11 and the temperature wave absorption surface 12; A second temperature sensor 320 for measuring the second temperature wave T2 at a predetermined internal position 14; and a third temperature sensor 330 for measuring the temperature of the temperature wave absorption surface 12.
　ここで、周期加熱法について説明する。周期加熱法においては、試験体１０の周期加熱面１１から内部に、一次元方向（図１に示す矢印Ｄの指す方向）に温度波を伝播させ、当該周期加熱面１１で測定される第一温度波Ｔ１（図２に示すθ０ｓｉｎ（ωｔ）で近似される温度波）と、当該内部の所定の位置１４で測定される第二温度波Ｔ２（図２に示すθ１ｓｉｎ（ωｔ＋φ）で近似される温度波）との振幅比Ａ（＝θ１／θ０：振幅の減衰率を示す比率）又は位相差φから、当該試験体１０の熱拡散率を求める。なお、試験体１０の内部を伝播する温度波は、次第に減衰するため、第二温度波Ｔ２の振幅θ１は、第一温度波Ｔ１の振幅θ０より小さい。 Here, the periodic heating method will be described. In the periodic heating method, a temperature wave is propagated in a one-dimensional direction (a direction indicated by an arrow D shown in FIG. 1) from the periodic heating surface 11 of the test body 10 to be measured on the periodic heating surface 11. A temperature wave T1 (temperature wave approximated by θ 0 sin (ωt) shown in FIG. 2) and a second temperature wave T2 (θ 1 sin (ωt + φ shown in FIG. 2) measured at a predetermined position 14 inside the temperature wave T1. The thermal diffusivity of the specimen 10 is obtained from the amplitude ratio A (= θ 1 / θ 0 : ratio indicating the attenuation rate of the amplitude) or the phase difference φ. Since the temperature wave propagating through the test body 10 is gradually attenuated, the amplitude θ 1 of the second temperature wave T2 is smaller than the amplitude θ 0 of the first temperature wave T1.
　また、試験体１０の周期加熱面１１と反対側の温度波吸収面１２（温度波が伝播する一次元方向における周期加熱面１１と反対側の試験体１０の表面）の温度Ｔ３は、図２に示すように、所定の一定値θ２に維持されていると仮定する。 Also, the temperature T3 of the temperature wave absorption surface 12 opposite to the periodic heating surface 11 of the test body 10 (the surface of the test body 10 opposite to the periodic heating surface 11 in the one-dimensional direction in which the temperature wave propagates) is shown in FIG. As shown in FIG. 2 , it is assumed that the predetermined constant value θ 2 is maintained.
　すなわち、周期加熱法においては、試験体１０の周期加熱面１１から温度波吸収面１２への一次元方向の熱流を仮定する。具体的に、例えば、図１に示すように、この一次元方向（矢印Ｄの指す方向）にｘ軸を設定し、試験体１０の厚さ（周期加熱面１１と温度波吸収面１２との距離）がｄであるとすると，当該ｘ軸の原点（ｘ＝０）の位置に当該試験体１０の温度波吸収面１２が配置され、ｘ＝ｄの位置に当該試験体１０の周期加熱面１１が配置される。 That is, in the periodic heating method, a one-dimensional heat flow from the periodic heating surface 11 of the test body 10 to the temperature wave absorption surface 12 is assumed. Specifically, for example, as shown in FIG. 1, the x-axis is set in this one-dimensional direction (the direction indicated by the arrow D), and the thickness of the test body 10 (the periodic heating surface 11 and the temperature wave absorption surface 12 are If the distance) is d, the temperature wave absorption surface 12 of the test body 10 is arranged at the position of the origin (x = 0) of the x-axis, and the periodic heating surface of the test body 10 is at the position of x = d. 11 is arranged.
　ここで、原点の温度（温度波吸収面１２の温度）は所定の一定値に維持され、ｘ＝ｄの位置の温度（周期加熱面１１の温度）は、ｓｉｎ（ωｔ＋η）で表される周期（ωは角振動数［ｓ－１］、ｔは時間［ｓ］、ηは任意の位相［ｒａｄ］である。）で変化していると仮定する。 Here, the temperature of the origin (the temperature of the temperature wave absorption surface 12) is maintained at a predetermined constant value, and the temperature at the position x = d (the temperature of the periodic heating surface 11) is a cycle represented by sin (ωt + η). (Ω is angular frequency [s −1 ], t is time [s], and η is an arbitrary phase [rad]).
　そして、上述のとおり、試験体１０の周期加熱面１１に第一温度波Ｔ１が与えられ、当該試験体１０の内部の所定位置１４に第二温度波Ｔ２が到達し、当該試験体１０の温度波吸収面１２の温度は所定の一定値θ２に維持されるという条件の下で一次元の熱伝導方程式を解くと、ｘ＝ｄの位置（周期加熱面１１）で測定される第一温度波Ｔ１と、任意の位置ｘ＝ｘｍ（ｄ＞ｘｍ＞０）（例えば、試験体１０の内部の所定位置１４）で測定される第二温度波Ｔ２と、の振幅比Ａ（＝θ１／θ０）（θ０は第一温度波Ｔ１の振幅であり、θ１は第二温度波Ｔ２の振幅である。）及び位相差φは、それぞれ下記の式（Ｉ）及び式（ＩＩ）により求められる。
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000002
 And as above-mentioned, the 1st temperature wave T1 is given to the periodic heating surface 11 of the test body 10, the 2nd temperature wave T2 reaches | attains the predetermined position 14 inside the said test body 10, and the temperature of the said test body 10 is reached. When the temperature of the wave absorbing surface 12 solves the one-dimensional heat conduction equation under the condition that is maintained at a predetermined constant value theta 2, the first temperature measured at the position of x = d (cycle heating surface 11) The amplitude ratio A (= θ) between the wave T1 and the second temperature wave T2 measured at an arbitrary position x = x m (d> x m > 0) (for example, the predetermined position 14 inside the test body 10). 1 / θ 0 ) (θ 0 is the amplitude of the first temperature wave T 1 and θ 1 is the amplitude of the second temperature wave T 2) and the phase difference φ are respectively expressed by the following equations (I) and (II ).
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000002
　上記式（Ｉ）、（ＩＩ）において、ｋは下記の式（ＩＩＩ）で表され、ｉは虚数単位である。また、下記式（ＩＩＩ）において、ωは、下記の式（ＩＶ）で表される角振動数であり、κは熱拡散率［ｍ２／ｓ］である。また、下記式（ＩＶ）において、ｆは周期［ｓ］である。
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
 In the above formulas (I) and (II), k is represented by the following formula (III), and i is an imaginary unit. In the following formula (III), ω is an angular frequency represented by the following formula (IV), and κ is a thermal diffusivity [m 2 / s]. In the following formula (IV), f is the period [s].
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
　こうして、試験体１０の周期加熱面１１における第一温度波Ｔ１と、当該試験体１０の内部の所定位置１４における第二温度波Ｔ２とを比較することにより得られた振幅比Ａ又は位相差φに基づき、当該試験体１０の熱拡散率κが求められる。 Thus, the amplitude ratio A or the phase difference φ obtained by comparing the first temperature wave T1 on the periodic heating surface 11 of the test body 10 and the second temperature wave T2 at the predetermined position 14 inside the test body 10. Based on the above, the thermal diffusivity κ of the test body 10 is obtained.
　すなわち、まず振幅比Ａを上記式（Ｉ）に代入してｋを求め、次いで当該ｋの値を上記式（ＩＩＩ）に代入して、試験体１０の熱拡散率κ［ｍ２／ｓ］が得られる。同様に、位相差φ［ｒａｄ］を上記式（ＩＩ）に代入してｋを求め、当該ｋの値を上記式（ＩＩＩ）に代入して、試験体１０の熱拡散率κ［ｍ２／ｓ］が得られる。 That is, first, the amplitude ratio A is substituted into the above formula (I) to obtain k, and then the value of k is substituted into the above formula (III), so that the thermal diffusivity κ [m 2 / s] of the specimen 10 is obtained. Is obtained. Similarly, k is obtained by substituting the phase difference φ [rad] into the above formula (II), the value of k is substituted into the above formula (III), and the thermal diffusivity κ [m 2 / s] is obtained.
　さらに、試験体１０の熱伝導率λ［Ｗ／（ｍ・Ｋ）］は，上述のようにして得られた熱拡散率κ［ｍ２／ｓ］と、別途測定された当該試験体１０の密度ρ［ｋｇ／ｍ３］及び比熱ｃ［Ｊ／（ｋｇ・Ｋ）］とを下記の式（Ｖ）に代入することにより求められる。
Figure JPOXMLDOC01-appb-M000005
 Further, the thermal conductivity λ [W / (m · K)] of the test body 10 is equal to the thermal diffusivity κ [m 2 / s] obtained as described above and the test body 10 measured separately. It is obtained by substituting the density ρ [kg / m 3 ] and the specific heat c [J / (kg · K)] into the following equation (V).
Figure JPOXMLDOC01-appb-M000005
　本装置１００は、上述のような周期加熱法により試験体１０の熱拡散率を測定する本方法において好ましく使用される。本装置１００は、図３に示すように、周期加熱ヒータ１１０及び温度波吸収ヒータ１２０を有している。周期加熱ヒータ１１０は、試験体１０の周期加熱面１１に温度波を与えるよう当該周期加熱面１１を加熱する。 The present apparatus 100 is preferably used in the present method for measuring the thermal diffusivity of the specimen 10 by the periodic heating method as described above. The apparatus 100 includes a periodic heater 110 and a temperature wave absorption heater 120 as shown in FIG. The periodic heater 110 heats the periodic heating surface 11 so as to give a temperature wave to the periodic heating surface 11 of the test body 10.
　図３に示す例において、周期加熱ヒータ１１０には、直流電源２００と、ファンクションジェネレーター２１０とが接続されている。直流電源２００は、周期加熱ヒータ１１０に直流電流を供給する。ファンクションジェネレーター２１０は、周期加熱ヒータ１１０が発生させる温度波の周期及び振幅を設定する装置である。周期加熱ヒータ１１０は、ファンクションジェネレーター２１０によって設定された周期及び振幅を有する温度波を、直流電源２００を介して発生させる。 In the example shown in FIG. 3, a DC power supply 200 and a function generator 210 are connected to the periodic heater 110. The DC power source 200 supplies a DC current to the periodic heater 110. The function generator 210 is a device that sets the period and amplitude of the temperature wave generated by the periodic heater 110. The periodic heater 110 generates a temperature wave having a period and amplitude set by the function generator 210 via the DC power supply 200.
　温度波吸収ヒータ１２０は、試験体１０の温度波吸収面１２の温度が所定の一定値θ２に維持されるよう当該温度波吸収面１２の加熱を調節する。 Temperature wave absorption heater 120 adjusts the heating of the temperature wave absorbing surface 12 so that the temperature of the temperature wave absorbing surface 12 of the specimen 10 is maintained at a predetermined constant value theta 2.
　また、本装置１００は、試験体１０の側面１３（図１及び図３に示すように、周期加熱面１１と温度波吸収面１２とをつなぐ試験体１０の表面）の温度を所定範囲内に維持するために、当該側面１３に対向して配置される周囲ヒータ１３０を有している。周囲ヒータ１３０は、試験体１０の側面１３の温度が所定範囲内に維持されるよう当該側面１３の加熱を調節する。 Further, the apparatus 100 keeps the temperature of the side surface 13 of the test body 10 (the surface of the test body 10 connecting the periodic heating surface 11 and the temperature wave absorption surface 12 as shown in FIGS. 1 and 3) within a predetermined range. In order to maintain, it has the surrounding heater 130 arrange | positioned facing the said side surface 13 concerned. The ambient heater 130 adjusts the heating of the side surface 13 so that the temperature of the side surface 13 of the test body 10 is maintained within a predetermined range.
　周囲ヒータ１３０の配置は、当該周囲ヒータ１３０が側面１３に対向して配置されれば特に限られないが、図３に示す例において、当該周囲ヒータ１３０は、隙間Ｇを介して当該側面１３に対向して配置されている。この隙間Ｇは、気体（例えば、空気）が充填された空間であることとしてもよいし、真空であることとしてもよい。周囲ヒータ１３０の形状は特に限られないが、当該周囲ヒータ１３０は、例えば、試験体１０の側面１３を囲む筒状のヒータ（例えば、円筒ヒータ）であることとしてもよい。 The arrangement of the surrounding heater 130 is not particularly limited as long as the surrounding heater 130 is arranged to face the side surface 13. However, in the example illustrated in FIG. 3, the surrounding heater 130 is disposed on the side surface 13 through the gap G. Opposed to each other. The gap G may be a space filled with gas (for example, air) or a vacuum. Although the shape of the surrounding heater 130 is not particularly limited, the surrounding heater 130 may be, for example, a cylindrical heater (for example, a cylindrical heater) surrounding the side surface 13 of the test body 10.
　周期加熱ヒータ１１０、温度波吸収ヒータ１２０及び周囲ヒータ１３０は、それぞれ試験体１０の周期加熱面１１、温度波吸収面１２及び側面１３を加熱できるヒータであれば特に限られないが、例えば、電熱ヒータ、ランプヒータ又はレーザー照射装置である。 The periodic heater 110, the temperature wave absorption heater 120, and the surrounding heater 130 are not particularly limited as long as they can heat the periodic heating surface 11, the temperature wave absorption surface 12, and the side surface 13 of the test body 10, respectively. It is a heater, a lamp heater or a laser irradiation device.
　また、本装置１００は、第一温度センサ３１０、第二温度センサ３２０及び第三温度センサ３３０を有している。第一温度センサ３１０、第二温度センサ３２０及び第三温度センサ３３０は、図１及び図３に示すように、温度波が伝播される一次元方向において直線的に配置されることが好ましい。 The apparatus 100 includes a first temperature sensor 310, a second temperature sensor 320, and a third temperature sensor 330. As shown in FIGS. 1 and 3, the first temperature sensor 310, the second temperature sensor 320, and the third temperature sensor 330 are preferably arranged linearly in a one-dimensional direction in which a temperature wave is propagated.
　すなわち、第一温度センサ３１０、第二温度センサ３２０及び第三温度センサ３３０は、例えば、周期加熱面１１から温度波吸収面１２に引いた仮想的な垂線上に配置されることが好ましく、当該垂線を中心とする半径５ｍｍ以下の当該周期加熱面１１に平行な仮想的な円内に配置されることとしてもよい。 In other words, the first temperature sensor 310, the second temperature sensor 320, and the third temperature sensor 330 are preferably arranged on a virtual perpendicular drawn from the periodic heating surface 11 to the temperature wave absorption surface 12, for example. It is good also as arrange | positioning in the virtual circle | round | yen parallel to the said periodic heating surface 11 whose radius is 5 mm or less centering on a perpendicular.
　温度波吸収ヒータ１２０は、第三温度センサ３３０による温度波吸収面１２の温度の測定結果に基づいて、当該温度波吸収面１２の温度が所定の一定値に維持されるよう、当該温度波吸収面１２の加熱を調節する。 Based on the measurement result of the temperature wave absorption surface 12 by the third temperature sensor 330, the temperature wave absorption heater 120 absorbs the temperature wave absorption so that the temperature of the temperature wave absorption surface 12 is maintained at a predetermined constant value. Adjust the heating of surface 12.
　また、図３に示す例において、本装置１００は、周囲ヒータ１３０による加熱を調節するための第四温度センサ３４０を有している。この例において、第四温度センサ３４０は、試験体１０の側面１３に対向する、周囲ヒータ１３０の表面と接触して配置されている。周囲ヒータ１３０は、第四温度センサ３４０による温度の測定結果に基づいて、当該周囲ヒータ１３０の出力（当該周囲ヒータ１３０による加熱）を調節する。 Further, in the example shown in FIG. 3, the apparatus 100 includes a fourth temperature sensor 340 for adjusting the heating by the ambient heater 130. In this example, the fourth temperature sensor 340 is disposed in contact with the surface of the surrounding heater 130 facing the side surface 13 of the test body 10. The ambient heater 130 adjusts the output of the ambient heater 130 (heating by the ambient heater 130) based on the temperature measurement result by the fourth temperature sensor 340.
　第一温度センサ３１０、第二温度センサ３２０、第三温度センサ３３０及び第四温度センサ３４０は、例えば、熱電対又は白金抵抗体である。 The first temperature sensor 310, the second temperature sensor 320, the third temperature sensor 330, and the fourth temperature sensor 340 are, for example, a thermocouple or a platinum resistor.
　なお、第一温度センサ３１０、第二温度センサ３２０、第三温度センサ３３０及び第四温度センサ３４０の厚さが、試験体１０の厚さに比べて無視できないくらい大きい場合には、当該温度センサを介した熱損失によって温度波が歪み、測定の誤差が生じる。このため、第一温度センサ３１０、第二温度センサ３２０、第三温度センサ３３０及び第四温度センサ３４０の厚さは、例えば、試験体１０の厚さｄの１０分の１以下であることが好ましい。 When the thicknesses of the first temperature sensor 310, the second temperature sensor 320, the third temperature sensor 330, and the fourth temperature sensor 340 are so large that they cannot be ignored compared to the thickness of the test body 10, the temperature sensor Due to the heat loss through the temperature wave, the temperature wave is distorted, resulting in measurement errors. For this reason, the thickness of the first temperature sensor 310, the second temperature sensor 320, the third temperature sensor 330, and the fourth temperature sensor 340 may be, for example, one tenth or less of the thickness d of the test body 10. preferable.
　すなわち、例えば、第一温度センサ３１０、第二温度センサ３２０、第三温度センサ３３０及び第四温度センサ３４０が、筐体を有する熱電対である場合には、当該筐体の厚さ（熱電対が円筒状の筐体を有する場合には、当該筐体の直径）が試験体１０の厚さｄの１０分の１以下であることが好ましい。 That is, for example, when the first temperature sensor 310, the second temperature sensor 320, the third temperature sensor 330, and the fourth temperature sensor 340 are thermocouples having a casing, the thickness of the casing (thermocouple) Is a cylindrical case, the diameter of the case is preferably 1/10 or less of the thickness d of the test body 10.
　また、図３に示す例において、本装置１００は、温度波吸収ヒータ１２０の試験体１０と反対側に配置された冷却装置１４０を有する。冷却装置１４０は、温度波が温度波吸収面１２に効率よく吸収されるように、温度波吸収ヒータ１２０を冷却する。冷却装置１４０は、例えば、冷媒を含む冷却タンクである。 Further, in the example shown in FIG. 3, the apparatus 100 includes a cooling device 140 disposed on the opposite side of the temperature wave absorption heater 120 from the test body 10. The cooling device 140 cools the temperature wave absorption heater 120 so that the temperature wave is efficiently absorbed by the temperature wave absorption surface 12. The cooling device 140 is a cooling tank containing a refrigerant, for example.
　また、図３に示す例において、本装置１００は、周期加熱ヒータ１１０の試験体１０と反対側に配置された補助ヒータ１５０を有する。補助ヒータ１５０は、周期加熱ヒータ１１０からの熱損失を低減させるよう当該周期加熱ヒータ１１０を保温する。補助ヒータ１５０は、例えば、電熱ヒータである。 Further, in the example shown in FIG. 3, the apparatus 100 includes an auxiliary heater 150 disposed on the opposite side to the test body 10 of the periodic heater 110. The auxiliary heater 150 keeps the periodic heater 110 warm so as to reduce heat loss from the periodic heater 110. The auxiliary heater 150 is, for example, an electric heater.
　また、図３に示す例において、本装置１００は、周囲ヒータ１３０と補助ヒータ１５０との間に配置された断熱材１６０を有する。この断熱材１６０は、試験体１０の周囲の熱的安定性を確保する。また、図３に示す例において、本装置１００は、冷却装置１４０の周囲に配置された断熱材１７０を有する。この断熱材１７０は、試験体１０の周囲の熱的安定性を確保する。また、図３に示す例においては、上述した測定系が金属板１８０（例えば、ステンレス板）の上に配置されるとともに、筐体１９０（例えば、ベルジャー）により覆われている。 Further, in the example shown in FIG. 3, the apparatus 100 includes a heat insulating material 160 disposed between the surrounding heater 130 and the auxiliary heater 150. This heat insulating material 160 ensures the thermal stability around the test body 10. In the example shown in FIG. 3, the apparatus 100 includes a heat insulating material 170 disposed around the cooling device 140. This heat insulating material 170 ensures thermal stability around the test body 10. In the example shown in FIG. 3, the measurement system described above is disposed on a metal plate 180 (for example, a stainless steel plate) and covered with a casing 190 (for example, a bell jar).
　測定の対象となる試験体１０は、周期加熱ヒータ１１０と温度波吸収ヒータ１２０との間に配置されるものであれば特に限られない。具体的に、試験体１０は、例えば、断熱材、断熱材と他の部材との積層体、プラスチック、金属、木材、石膏ボード及びセメントからなる群より選択されることとしてもよい。より具体的に、断熱材は、例えば、繊維質断熱材、多孔質断熱材又は真空断熱材であることとしてもよい。 The test object 10 to be measured is not particularly limited as long as it is arranged between the periodic heater 110 and the temperature wave absorption heater 120. Specifically, the test body 10 may be selected from the group consisting of a heat insulating material, a laminated body of a heat insulating material and another member, plastic, metal, wood, gypsum board, and cement, for example. More specifically, the heat insulating material may be, for example, a fibrous heat insulating material, a porous heat insulating material, or a vacuum heat insulating material.
　繊維質断熱材は、例えば、ロックウール断熱材、グラスウール断熱材、アルミナ系繊維質断熱材（例えば、アルミナファイバーウール断熱材）、及びアルミナシリカ系繊維質断熱材からなる群より選択されることとしてもよい。 The fibrous heat insulating material is selected from the group consisting of, for example, rock wool heat insulating material, glass wool heat insulating material, alumina-based fiber heat insulating material (for example, alumina fiber wool heat insulating material), and alumina-silica-based fiber heat insulating material. Also good.
　多孔質断熱材は、例えば、無機多孔質断熱材（例えば、ケイ酸カルシウム断熱材）又は発泡樹脂断熱材（例えば、発泡ゴム成形体、発泡ポリウレタン成形体又は発泡スチロール成形体）からなる群より選択されることとしてもよい。 The porous heat insulating material is selected from the group consisting of, for example, an inorganic porous heat insulating material (for example, calcium silicate heat insulating material) or a foamed resin heat insulating material (for example, a foamed rubber molded body, a foamed polyurethane molded body, or a polystyrene foam molded body). It is also good to do.
　断熱材と他の部材との積層体は、例えば、当該断熱材と、当該断熱材に積層された金属部材及び／又はガラス部材とを有する積層体であることとしてもよい。 The laminated body of a heat insulating material and another member is good also as being a laminated body which has the said heat insulating material and the metal member and / or glass member which were laminated | stacked on the said heat insulating material, for example.
　また、本方法においては、後述のとおり、比較的高い温度（例えば、８００℃以上）で比較的低い熱伝導率を示す試験体１０の熱拡散率を高い精度で測定することができる。そこで、例えば、試験体１０は、例えば、１０００℃において０．５Ｗ／（ｍ・Ｋ）以下の熱伝導率を有することとしてもよく、１０００℃において０．３Ｗ／（ｍ・Ｋ）以下の熱伝導率を有することとしてもよく、１０００℃において０．２Ｗ／（ｍ・Ｋ）以下の熱伝導率を有することとしてもよい。なお、試験体１０の熱伝導率の下限値は特に限られないが、例えば、当該試験体１０は、１０００℃において０．０１Ｗ／（ｍ・Ｋ）以上の熱伝導率を有することとしてもよい。 Moreover, in this method, as will be described later, the thermal diffusivity of the test specimen 10 exhibiting a relatively low thermal conductivity at a relatively high temperature (for example, 800 ° C. or higher) can be measured with high accuracy. Therefore, for example, the test body 10 may have a thermal conductivity of 0.5 W / (m · K) or less at 1000 ° C., for example, and a heat of 0.3 W / (m · K) or less at 1000 ° C. It may have conductivity, or may have thermal conductivity of 0.2 W / (m · K) or less at 1000 ° C. The lower limit value of the thermal conductivity of the test body 10 is not particularly limited. For example, the test body 10 may have a thermal conductivity of 0.01 W / (m · K) or more at 1000 ° C. .
　試験体１０の形状は、周期加熱ヒータ１１０と温度波吸収ヒータ１２０との間に配置されるものであれば特に限られないが、例えば、平板状であることが好ましい。試験体１０が平板状である場合には、周期加熱面１１と温度波吸収面１２とは略平行に配置される。 Although the shape of the test body 10 is not particularly limited as long as it is disposed between the periodic heater 110 and the temperature wave absorption heater 120, for example, a flat plate shape is preferable. When the test body 10 has a flat plate shape, the periodic heating surface 11 and the temperature wave absorption surface 12 are arranged substantially in parallel.
　試験体１０は、１つの試験体からなることとしてもよいし、温度波が伝播する方向に積層された２つ以上の同質の試験体からなることとしてもよい。すなわち、試験体１０は、例えば、１つの板状断熱材であることとしてもよいし、２つ以上の同一種類の板状断熱材が積層してなる積層体であることとしてもよい。 The test body 10 may be composed of a single test body, or may be composed of two or more homogeneous test bodies stacked in the direction in which the temperature wave propagates. That is, the test body 10 may be, for example, one plate-like heat insulating material or a laminated body formed by laminating two or more same types of plate-like heat insulating materials.
　試験体１０が２つ以上の試験体を積層してなる場合、隣接する２つの試験体の間に隙間が形成されると、当該２つの試験体の間に気体（空気）の層が形成され、測定結果が気体の熱伝導率の影響を受け、誤差が生じる。 When the test body 10 is formed by stacking two or more test bodies, if a gap is formed between two adjacent test bodies, a gas (air) layer is formed between the two test bodies. The measurement result is affected by the thermal conductivity of the gas, and an error occurs.
　このため、試験体１０が２つ以上の試験体を積層してなる場合、温度波が伝播する方向に隣接する一対の当該試験体において、一方の試験体の表面と、当該表面に対向する他方の試験体の表面との間には、例えば、０．５ｍｍ以上の隙間を形成しないことが好ましい。 For this reason, when the test body 10 is formed by laminating two or more test bodies, in a pair of the test bodies adjacent in the direction in which the temperature wave propagates, the surface of one test body and the other facing the surface For example, it is preferable not to form a gap of 0.5 mm or more between the surface of the test body.
　そして、本方法においては、まず、試験体１０の周期加熱面１１から温度波吸収面１２に向けて温度波を伝播させる。すなわち、周期加熱面１１に対向する周期加熱ヒータ１１０によって、所定の周期及び所定の振幅を有する温度波を発生させる。その結果、試験体１０の周期加熱面１１には、周期加熱ヒータ１１０が発生させた温度波に対応する温度波が与えられる。 In this method, first, a temperature wave is propagated from the periodic heating surface 11 of the test body 10 toward the temperature wave absorption surface 12. That is, a temperature wave having a predetermined period and a predetermined amplitude is generated by the periodic heater 110 facing the periodic heating surface 11. As a result, a temperature wave corresponding to the temperature wave generated by the periodic heater 110 is given to the periodic heating surface 11 of the test body 10.
　本方法において、周期加熱面１１に与えられ、試験体１０の内部を伝播する温度波は、完全に減衰することはなく、温度波吸収面１２に到達する。すなわち、周期加熱ヒータ１１０は、試験体１０の温度波吸収面１２に到達する温度波を、当該試験体１０の周期加熱面１１に与える。 In this method, the temperature wave given to the periodic heating surface 11 and propagating through the inside of the test body 10 reaches the temperature wave absorption surface 12 without being completely attenuated. That is, the periodic heater 110 gives a temperature wave that reaches the temperature wave absorbing surface 12 of the test body 10 to the periodic heating surface 11 of the test body 10.
　また、周期加熱ヒータ１１０は、振幅の中心が所定温度である温度波を発生させる。振幅の中心の温度は、特に限られないが、例えば、－１９０℃～１５００℃の範囲内の所定温度であることとしてもよく、２５℃～１５００℃の範囲内の所定温度であることとしてもよく、７００℃～１５００℃の範囲内の所定温度であることとしてもよく、８００℃～１５００℃の範囲内の所定温度であることとしてもよい。本方法においては、このような比較的高い温度（例えば、７００℃～１５００℃又は８００℃～１５００℃）においても、試験体１０の熱拡散率を高い精度で測定することができる。 Further, the periodic heater 110 generates a temperature wave whose center of amplitude is a predetermined temperature. The temperature at the center of the amplitude is not particularly limited. For example, the temperature may be a predetermined temperature within a range of −190 ° C. to 1500 ° C., or may be a predetermined temperature within a range of 25 ° C. to 1500 ° C. Alternatively, the temperature may be a predetermined temperature within a range of 700 ° C. to 1500 ° C., or may be a predetermined temperature within a range of 800 ° C. to 1500 ° C. In this method, the thermal diffusivity of the specimen 10 can be measured with high accuracy even at such a relatively high temperature (for example, 700 ° C. to 1500 ° C. or 800 ° C. to 1500 ° C.).
　なお、例えば、試験体１０の１０００℃における熱拡散率を測定する場合には、周期加熱面１１における温度波の振幅の中心温度と、温度波吸収面１２における所定の一定温度との算術平均値が１０００℃となるような条件で測定を行う。 For example, when measuring the thermal diffusivity of the test body 10 at 1000 ° C., the arithmetic average value of the center temperature of the amplitude of the temperature wave on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12 Is measured under such conditions that the temperature becomes 1000 ° C.
　また、温度波の振幅が大きすぎる場合には、例えば、試験体１０の周囲の気体（試験体１０の側面１３と接している気体（隙間Ｇに充填されている気体））、当該気体と接している周囲ヒータ１３０、熱損失を防ぐために配置されている断熱材１６０，１７０等の他の部材の温度が周期的に変化して別の温度波が形成されてしまう。 Further, when the amplitude of the temperature wave is too large, for example, the gas around the test body 10 (the gas in contact with the side surface 13 of the test body 10 (the gas filled in the gap G)) is in contact with the gas. The temperature of other members such as the surrounding heater 130 and the heat insulating materials 160 and 170 arranged to prevent heat loss periodically changes to form another temperature wave.
　そして、この別の温度波が試験体１０の側面１３から当該試験体１０の内部へ侵入し、周期加熱面１１から温度波吸収面１２に向けて伝播している本来の温度波と重なり、測定誤差が生じる。 Then, this other temperature wave penetrates into the inside of the test body 10 from the side surface 13 of the test body 10 and overlaps with the original temperature wave propagating from the periodic heating surface 11 toward the temperature wave absorption surface 12, and is measured. An error occurs.
　このため、周期加熱ヒータ１１０で発生させる温度波の振幅は、例えば、１℃～１０℃の範囲内の所定値であることが好ましく、１℃～５℃の範囲内の所定値であることがより好ましく、２℃～４℃の範囲内の所定値であることが特に好ましい。 Therefore, the amplitude of the temperature wave generated by the periodic heater 110 is preferably a predetermined value within a range of 1 ° C. to 10 ° C., for example, and is preferably a predetermined value within a range of 1 ° C. to 5 ° C. More preferably, the predetermined value is in the range of 2 ° C. to 4 ° C.
　また、周期加熱ヒータ１１０で発生させる温度波は、例えば、所定温度±１０℃の範囲内で変化することが好ましく、所定温度±５℃の範囲内で変化することが好ましく、所定温度±２℃の範囲内で変化することが好ましい。 Further, the temperature wave generated by the periodic heater 110 preferably changes within a range of a predetermined temperature ± 10 ° C., for example, preferably changes within a range of a predetermined temperature ± 5 ° C., and the predetermined temperature ± 2 ° C. It is preferable to change within the range.
　温度波の振幅が上記の適切な範囲内であることにより、試験体１０に温度波を適切に伝播させることができ、測定精度を高めることができる。なお、例えば、温度波の振幅の中心の温度が１０００℃であり、当該振幅が５℃である場合、当該温度波は、１０００±５℃の範囲内（９９５℃～１００５℃）で周期的に変化する。 When the amplitude of the temperature wave is within the above appropriate range, the temperature wave can be properly propagated to the test body 10 and the measurement accuracy can be improved. For example, when the temperature at the center of the amplitude of the temperature wave is 1000 ° C. and the amplitude is 5 ° C., the temperature wave is periodically within a range of 1000 ± 5 ° C. (995 ° C. to 1005 ° C.). Change.
　また、温度波の周期が長すぎる場合、試験体１０の温度が、当該試験体１０内の当該温度波が伝播する方向における全ての位置でほぼ均一に変化してしまい、当該試験体１０の内部を当該温度波が伝播するという状態を形成することができなくなり、測定誤差が生じる。一方、温度波の周期が短すぎる場合、当該温度波が試験体１０の内部を伝播する間に、当該温度波が途中で完全に減衰して消滅してしまい、測定誤差が生じる。 If the period of the temperature wave is too long, the temperature of the test body 10 changes almost uniformly at all positions in the direction in which the temperature wave propagates in the test body 10, and the inside of the test body 10 Thus, a state in which the temperature wave propagates cannot be formed, and a measurement error occurs. On the other hand, when the period of the temperature wave is too short, while the temperature wave propagates through the inside of the test body 10, the temperature wave is completely attenuated and disappears on the way, resulting in a measurement error.
　このため、周期加熱ヒータ１１０で発生させる温度波の周期は、例えば、１分～１２０分の範囲内の所定値であることが好ましく、１５分～１００分の範囲内の所定値であることがより好ましく、３０分～６０分の範囲内の所定値であることが特に好ましい。温度波の周期が上記の適切な範囲内であることにより、試験体１０に温度波を適切に伝播させることができ、測定精度を高めることができる。 Therefore, the period of the temperature wave generated by the periodic heater 110 is preferably a predetermined value within a range of 1 minute to 120 minutes, for example, and is preferably a predetermined value within a range of 15 minutes to 100 minutes. More preferably, the predetermined value is within a range of 30 minutes to 60 minutes. When the period of the temperature wave is within the appropriate range, the temperature wave can be appropriately propagated to the test body 10 and the measurement accuracy can be increased.
　また、温度波の振幅の中心の温度が一定とならず、時間の経過とともに上昇又は下降する場合（温度波がドリフトする場合）には、当該温度波が歪んでしまうため、周期加熱面１１における第一温度波Ｔ１と、試験体１０の内部の所定位置１４における第二温度波Ｔ２との振幅比又は位相差を正確に測定できなくなり、測定誤差が生じる。 Further, when the temperature at the center of the amplitude of the temperature wave is not constant and rises or falls as time passes (when the temperature wave drifts), the temperature wave is distorted. The amplitude ratio or phase difference between the first temperature wave T1 and the second temperature wave T2 at the predetermined position 14 inside the test body 10 cannot be measured accurately, resulting in a measurement error.
　このため、例えば、試験体１０を伝播する、連続する３周期分の温度波（例えば、第一温度センサ３１０及び／又は第二温度センサ３２０により測定される）において、各１周期分の温度波の振幅の中心温度の平均値と、当該３周期分の温度波の振幅の中心温度の平均値との差分が、±２℃以内であることが好ましく、±１℃以内であることがより好ましく、±０．２℃以内であることが特に好ましい。 For this reason, for example, in a continuous three-cycle temperature wave (for example, measured by the first temperature sensor 310 and / or the second temperature sensor 320) propagating through the test body 10, a temperature wave for one cycle each. The difference between the average value of the center temperature of the amplitude and the average value of the center temperature of the amplitude of the temperature wave for the three cycles is preferably within ± 2 ° C, more preferably within ± 1 ° C. It is particularly preferable that the temperature is within ± 0.2 ° C.
　また、例えば、試験体１０を伝播する、連続する３周期分の温度波において、各１周期分の温度波の振幅の中心温度の平均値の、当該３周期分の振幅の中心温度の平均値に対する変化率（当該各１周期分の平均値から当該３周期分の平均値を減じた値を、当該３周期分の平均値で除して得られた値に、１００を乗じて算出される変化率）が、±２％以内であることが好ましく、±０．５％以内であることがより好ましく、±０．２％以内であることが特に好ましい。このように温度波のドリフトを抑制することにより、温度波の振幅比又は位相差を正確に測定することができ、熱拡散率の測定精度を高めることができる。 Further, for example, in the temperature wave for three consecutive cycles propagating through the test body 10, the average value of the center temperature of the amplitude of the temperature wave for each one cycle, the average value of the center temperature of the amplitude for the three cycles The rate of change with respect to (calculated by multiplying the value obtained by dividing the average value for the three periods from the average value for the one period by the average value for the three periods multiplied by 100 Change rate) is preferably within ± 2%, more preferably within ± 0.5%, and particularly preferably within ± 0.2%. Thus, by suppressing the drift of the temperature wave, the amplitude ratio or phase difference of the temperature wave can be accurately measured, and the measurement accuracy of the thermal diffusivity can be increased.
　また、本方法においては、試験体１０の周期加熱面１１から温度波吸収面１２に向けて温度波を伝播させている間、当該温度波吸収面１２の温度を、所定の一定値となるよう調節する。 Further, in this method, while the temperature wave is propagated from the periodic heating surface 11 of the test body 10 toward the temperature wave absorption surface 12, the temperature of the temperature wave absorption surface 12 is set to a predetermined constant value. Adjust.
　すなわち、温度波吸収面１２の温度が所定の一定値となるよう、温度波吸収ヒータ１２０による当該温度波吸収面１２の加熱を調節する。このとき、温度波吸収ヒータ１２０は、第三温度センサ３３０による温度波吸収面１２の温度の測定結果に基づき、温度波吸収面１２の加熱を調節する。 That is, the heating of the temperature wave absorption surface 12 by the temperature wave absorption heater 120 is adjusted so that the temperature of the temperature wave absorption surface 12 becomes a predetermined constant value. At this time, the temperature wave absorption heater 120 adjusts the heating of the temperature wave absorption surface 12 based on the temperature measurement result of the temperature wave absorption surface 12 by the third temperature sensor 330.
　具体的に、温度波吸収ヒータ１２０は、温度波吸収面１２の温度が所定の一定値を下回った場合には、その出力を上げて当該温度波吸収面１２の加熱を強め、当該温度波吸収面１２の温度を上昇させる。 Specifically, when the temperature of the temperature wave absorption surface 12 falls below a predetermined constant value, the temperature wave absorption heater 120 increases its output to increase the heating of the temperature wave absorption surface 12 and absorb the temperature wave absorption. Increase the temperature of the surface 12.
　また、温度波吸収ヒータ１２０は、温度波吸収面１２の温度が所定の一定値を上回った場合には、その出力を下げて当該温度波吸収面１２の加熱を弱め、当該温度波吸収面１２の温度を低下させる。なお、温度波吸収面１２の加熱を弱める場合、上述した冷却装置１４０を作動させて、温度波吸収ヒータ１２０を冷却することとしてもよい。 Further, when the temperature of the temperature wave absorption surface 12 exceeds a predetermined constant value, the temperature wave absorption heater 120 decreases the output to weaken the heating of the temperature wave absorption surface 12, and the temperature wave absorption surface 12. Reduce the temperature. In addition, when weakening the heating of the temperature wave absorption surface 12, it is good also as operating the cooling device 140 mentioned above and cooling the temperature wave absorption heater 120. FIG.
　温度波吸収面１２の温度が調節されるべき所定の一定値は、例えば、周期加熱面１１における温度波の振幅の中心温度より、０℃～２０℃の範囲内の所定値だけ低い又は高い温度であることとしてもよく、当該振幅の中心温度より、０℃～１０℃の範囲内の所定値だけ低い又は高い温度であることとしてもよく、当該振幅の中心温度より、０℃～５℃の範囲内の所定値だけ低い又は高い温度であることとしてもよい。すなわち、温度波吸収面１２の温度が調節されるべき所定の一定値は、例えば、周期加熱面１１における温度波の振幅の中心温度±２０℃の範囲内の所定の一定値であることとしてもよく、当該中心温度±１０℃の範囲内の所定の一定値であることとしてもよく、中心温度±５℃の範囲内の所定の一定値であることとしてもよい。 The predetermined constant value at which the temperature of the temperature wave absorption surface 12 is to be adjusted is, for example, a temperature lower or higher than the central temperature of the amplitude of the temperature wave on the periodic heating surface 11 by a predetermined value in the range of 0 ° C. to 20 ° C. The temperature may be lower or higher than the center temperature of the amplitude by a predetermined value within a range of 0 ° C. to 10 ° C., and may be 0 ° C. to 5 ° C. from the center temperature of the amplitude. The temperature may be lower or higher by a predetermined value within the range. That is, the predetermined constant value to which the temperature of the temperature wave absorption surface 12 should be adjusted may be, for example, a predetermined constant value within the range of the center temperature ± 20 ° C. of the temperature wave amplitude on the periodic heating surface 11. Alternatively, it may be a predetermined constant value within the range of the center temperature ± 10 ° C., or may be a predetermined constant value within the range of the center temperature ± 5 ° C.
　また、本方法においては、上述のとおり、上記式（Ｉ）～（ＩＩＩ）を使って熱拡散率κを求める。この測定原理は、試験体１０の一方の表面（周期加熱面１１）の温度を周期的に変化させ、且つその反対側の表面（温度波吸収面１２）の温度を一定にするという条件で熱伝導方程式を解いて得られる解を使うというものであるが、実際には、温度波吸収面１２の温度を完全に一定にすることは不可能である。このため、温度波吸収面１２における温度の変動をどの程度まで抑えることができるかが、測定精度に大きく影響する。 In this method, as described above, the thermal diffusivity κ is obtained using the above formulas (I) to (III). This measurement principle is based on the condition that the temperature of one surface (periodic heating surface 11) of the test body 10 is periodically changed and the temperature of the opposite surface (temperature wave absorption surface 12) is kept constant. Although the solution obtained by solving the conduction equation is used, in practice, it is impossible to make the temperature of the temperature wave absorbing surface 12 completely constant. For this reason, the degree to which the temperature fluctuation on the temperature wave absorption surface 12 can be suppressed greatly affects the measurement accuracy.
　この点、温度波吸収面１２の温度は、所定の一定値±０．５℃の範囲内に維持することが好ましく、所定の一定値±０．２℃の範囲内に維持することがより好ましく、所定の一定値±０．０５℃の範囲内に維持することが特に好ましい。温度波吸収面１２の温度を上記のように所定の一定値又はその極近傍の温度に維持することにより、測定精度を高めることができる。 In this regard, the temperature of the temperature wave absorbing surface 12 is preferably maintained within a predetermined constant value ± 0.5 ° C., and more preferably maintained within a predetermined constant value ± 0.2 ° C. It is particularly preferable to maintain within a range of a predetermined constant value ± 0.05 ° C. By maintaining the temperature of the temperature wave absorption surface 12 at a predetermined constant value or a temperature in the vicinity thereof as described above, the measurement accuracy can be increased.
　また、温度波吸収面１２と温度波吸収ヒータ１２０との間に他の部材を配置すると、周期加熱面１１から伝播してきた温度波が、当該温度波吸収面１２で効率よく吸収されず（消滅せず）、測定誤差が生じることがある。 Further, when another member is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, the temperature wave propagated from the periodic heating surface 11 is not efficiently absorbed by the temperature wave absorption surface 12 (disappearance). Measurement error may occur.
　そこで、温度波吸収面１２と温度波吸収ヒータ１２０との間には他の部材を配置せず、当該温度波吸収面１２と温度波吸収ヒータ１２０とを接触させることとしてもよい。なお、温度波吸収面１２の温度を測定するための第三温度センサ３３０は、例えば、当該温度波吸収面１２と接触して配置されることとしてもよい。この場合、第三温度センサ３３０は、温度波吸収ヒータ１２０と接触することなく配置されることとしてもよい。 Therefore, another member may not be disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, and the temperature wave absorption surface 12 and the temperature wave absorption heater 120 may be brought into contact with each other. In addition, the 3rd temperature sensor 330 for measuring the temperature of the temperature wave absorption surface 12 is good also as arrange | positioning in contact with the said temperature wave absorption surface 12, for example. In this case, the third temperature sensor 330 may be arranged without contacting the temperature wave absorption heater 120.
　また、本方法においては、試験体１０の周期加熱面１１から温度波吸収面１２に向けて温度波を伝播させている間、当該試験体１０の側面１３の温度を、所定範囲内となるよう調節する。 Further, in this method, while the temperature wave is propagated from the periodic heating surface 11 of the test body 10 toward the temperature wave absorption surface 12, the temperature of the side surface 13 of the test body 10 is set within a predetermined range. Adjust.
　すなわち、試験体１０の側面１３の温度が所定範囲内となるよう、周囲ヒータ１３０による当該側面１３の加熱を調節する。このとき、周囲ヒータ１３０は、第四センサ３４０が温度を測定した結果に基づき、試験体１０の側面１３の加熱を調節する。 That is, the heating of the side surface 13 by the surrounding heater 130 is adjusted so that the temperature of the side surface 13 of the test body 10 is within a predetermined range. At this time, the ambient heater 130 adjusts the heating of the side surface 13 of the test body 10 based on the result of the temperature measured by the fourth sensor 340.
　具体的に、周囲ヒータ１３０は、測定温度が所定範囲を下回った場合には、その出力を上げて当該側面１３の加熱を強め、当該側面１３の温度を上昇させる。また、周囲ヒータ１３０は、測定温度が所定範囲を上回った場合には、その出力を下げて当該側面１３の加熱を弱め、当該側面１３の温度を低下させる。 Specifically, when the measured temperature falls below a predetermined range, the ambient heater 130 increases its output to increase the heating of the side surface 13 and increase the temperature of the side surface 13. In addition, when the measured temperature exceeds the predetermined range, the ambient heater 130 decreases the output to weaken the heating of the side surface 13 and decrease the temperature of the side surface 13.
　試験体１０の側面１３の温度が調節されるべき所定範囲は、例えば、周期加熱面１１における温度波の振幅の中心温度と温度波吸収面１２の所定の一定温度との算術平均値±５０℃の範囲であることが好ましく、当該算術平均値±２０℃の範囲であることがより好ましく、当該算術平均値±５℃の範囲であることが特に好ましい。 The predetermined range in which the temperature of the side surface 13 of the test body 10 should be adjusted is, for example, the arithmetic average value ± 50 ° C. between the center temperature of the temperature wave amplitude on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12. The arithmetic average value ± 20 ° C. is more preferable, and the arithmetic average value ± 5 ° C. is particularly preferable.
　また、本方法においては、試験体１０の周期加熱面１１から温度波吸収面１２に向けて温度波を伝播させている間、当該試験体１０の側面１３の温度を調節するための周囲ヒータ１３０の温度を、所定の範囲内となるよう調節することとしてもよい。 In this method, the ambient heater 130 for adjusting the temperature of the side surface 13 of the test body 10 while the temperature wave is propagated from the periodic heating surface 11 of the test body 10 toward the temperature wave absorption surface 12. The temperature may be adjusted to be within a predetermined range.
　すなわち、上述のとおり、周囲ヒータ１３０の温度が周期的に変化すると、周期加熱面１１から温度波吸収面１２に向けて伝播している本来の温度波と異なる別の温度波が形成され、測定誤差が生じる。 That is, as described above, when the temperature of the surrounding heater 130 changes periodically, another temperature wave different from the original temperature wave propagating from the periodic heating surface 11 toward the temperature wave absorption surface 12 is formed, and measurement is performed. An error occurs.
　このため、周囲ヒータ１３０の温度の変化は可能な限り抑えることが好ましい。そこで、周囲ヒータ１３０の温度を、所定の範囲内、すなわち所定の一定値及びその近傍に維持する。 For this reason, it is preferable to suppress the change in the temperature of the surrounding heater 130 as much as possible. Therefore, the temperature of the surrounding heater 130 is maintained within a predetermined range, that is, a predetermined constant value and the vicinity thereof.
　具体的に、図３に示すように、第四温度センサ３４０を、試験体１０の側面１３に対向する、周囲ヒータ３４０の表面に配置し、当該第四温度センサ３４０による温度の測定結果に基づき、当該測定される温度が所定の範囲内となるよう、当該周囲ヒータ１３０の出力（当該周囲ヒータ１３０による加熱）を調節する。 Specifically, as shown in FIG. 3, the fourth temperature sensor 340 is arranged on the surface of the surrounding heater 340 facing the side surface 13 of the test body 10, and based on the temperature measurement result by the fourth temperature sensor 340. The output of the surrounding heater 130 (heating by the surrounding heater 130) is adjusted so that the measured temperature is within a predetermined range.
　周囲ヒータ１３０の温度が調節されるべき所定範囲は、例えば、周期加熱面１１における温度波の振幅の中心温度と温度波吸収面１２の所定の一定温度との算術平均値±５０℃の範囲であることが好ましく、当該算術平均値±２０℃の範囲であることがより好ましく、当該算術平均値±５℃の範囲であることが特に好ましい。 The predetermined range in which the temperature of the surrounding heater 130 should be adjusted is, for example, a range of ± 50 ° C. arithmetic average value between the center temperature of the temperature wave amplitude on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12. The arithmetic average value is more preferably within a range of ± 20 ° C., and the arithmetic average value is preferably within a range of ± 5 ° C.
　次に、本方法においては、試験体１０の周期加熱面１１における第一温度波Ｔ１と、当該試験体１０の内部の所定位置１４における第二温度波Ｔ２とを測定する。すなわち、周期加熱ヒータ１１０から周期加熱面１１に与えられた温度波Ｔ１を第一温度センサ３１０によって測定するとともに、当該周期加熱面１１から試験体１０の内部の所定位置１４に伝播された第二温度波Ｔ２を第二温度センサ３２０によって測定する。 Next, in this method, a first temperature wave T1 on the periodic heating surface 11 of the test body 10 and a second temperature wave T2 at a predetermined position 14 inside the test body 10 are measured. That is, the temperature wave T <b> 1 applied from the periodic heater 110 to the periodic heating surface 11 is measured by the first temperature sensor 310 and transmitted from the periodic heating surface 11 to the predetermined position 14 inside the test body 10. The temperature wave T <b> 2 is measured by the second temperature sensor 320.
　そして、本方法においては、上述のようにして測定された第一温度波Ｔ１と第二温度波Ｔ２との振幅比又は位相差から試験体１０の熱拡散率を得る。すなわち、上述のとおり、第一温度波Ｔ１の振幅θ０と、第二温度波Ｔ２の振幅θ１とから振幅比Ａ（＝θ１／θ０）を求め、上記の式（Ｉ）と式（ＩＩＩ）とから熱拡散率κを求める。また、第一温度波Ｔ１と第二温度波Ｔ２との位相のずれから位相差φを求め、上記の式（ＩＩ）と式（ＩＩＩ）とから熱拡散率κを求める。 In this method, the thermal diffusivity of the specimen 10 is obtained from the amplitude ratio or phase difference between the first temperature wave T1 and the second temperature wave T2 measured as described above. That is, as described above, the amplitude ratio A (= θ 1 / θ 0 ) is obtained from the amplitude θ 0 of the first temperature wave T 1 and the amplitude θ 1 of the second temperature wave T 2, and the above equations (I) and The thermal diffusivity κ is obtained from (III). Further, the phase difference φ is obtained from the phase shift between the first temperature wave T1 and the second temperature wave T2, and the thermal diffusivity κ is obtained from the above formulas (II) and (III).
　ここで、本実施形態において特徴的なことの一つは、図３に示すように、本装置１００が、発熱体１２１と当該発熱体１２１の温度波吸収面１２側を覆う被覆材１２２とを有する温度波吸収ヒータ１２０と、当該温度波吸収面１２と温度波吸収ヒータ１２０との間に配置される、当該温度波吸収ヒータ１２０の当該被覆材１２２の熱容量より大きい熱容量を有する高熱容量部材４００とを有し、本方法において、当該温度波吸収面１２と対向する位置に、当該温度波吸収面１２の温度を所定の一定値に維持するための、発熱体１２１と当該発熱体１２１の当該温度波吸収面１２側を覆う被覆材１２２とを有する温度波吸収ヒータ１２０を配置し、当該温度波吸収面１２と当該温度波吸収ヒータ１２０との間に、当該温度波吸収ヒータ１２０の当該被覆材１２２の熱容量より大きい熱容量を有する当該高熱容量部材４００を配置した状態で、第一温度波Ｔ１及び第二温度波Ｔ２を測定することである。 Here, one of the characteristic features in the present embodiment is that, as shown in FIG. 3, the apparatus 100 includes a heating element 121 and a covering material 122 that covers the temperature wave absorbing surface 12 side of the heating element 121. And a high heat capacity member 400 having a heat capacity larger than the heat capacity of the covering material 122 of the temperature wave absorption heater 120 disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120. In this method, the heating element 121 and the heating element 121 for maintaining the temperature of the temperature wave absorption surface 12 at a predetermined constant value at a position facing the temperature wave absorption surface 12 are provided. A temperature wave absorption heater 120 having a covering material 122 covering the temperature wave absorption surface 12 side is disposed, and the temperature wave absorption heater 120 is interposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120. In the state in which the said high thermal capacity member 400 having a larger heat capacity than the heat capacity of the coating material 122, is to measure the first temperature wave T1 and the second temperature wave T2.
　すなわち、上述した測定原理においては、温度波吸収面１２（図１に示すｘ軸の原点）の温度が常に一定と仮定しているが、実際には、当該温度波吸収面１２の温度を厳密に一定に維持することは難しく、その結果、測定誤差が生じる。 That is, in the measurement principle described above, it is assumed that the temperature of the temperature wave absorption surface 12 (the origin of the x-axis shown in FIG. 1) is always constant. It is difficult to maintain a constant value as a result, resulting in measurement errors.
　具体的に、例えば、温度波の周期が比較的短い場合、温度波吸収ヒータ１２０の出力を素早く且つ頻繁に変化させることになる。しかしながら、例えば、温度波吸収ヒータ１２０の発熱体１２１の温度波吸収面１２側を覆う被覆材１２２の熱容量が小さい場合には、当該温度波吸収ヒータ１２０の出力を大きく変化させることにより、当該被覆材１２２の温度（温度波吸収面１２に対向する、温度波吸収ヒータ１２０の表面の温度）及び当該温度波吸収面１２の温度が急激に変化してしまい、当該温度波吸収面１２の温度を所定の一定値となるよう調節することが難しくなる。 Specifically, for example, when the period of the temperature wave is relatively short, the output of the temperature wave absorption heater 120 is changed quickly and frequently. However, for example, when the heat capacity of the covering material 122 that covers the temperature wave absorbing surface 12 side of the heating element 121 of the temperature wave absorbing heater 120 is small, the output of the temperature wave absorbing heater 120 is largely changed to thereby change the covering. The temperature of the material 122 (the temperature of the surface of the temperature wave absorption heater 120 facing the temperature wave absorption surface 12) and the temperature of the temperature wave absorption surface 12 change rapidly, and the temperature of the temperature wave absorption surface 12 is changed. It becomes difficult to adjust to a predetermined constant value.
　そこで、本発明においては、試験体１０の温度波吸収面１２と温度波吸収ヒータ１２０との間に、当該温度波吸収ヒータ１２０の被覆材１２２の熱容量より大きい熱容量を有する高熱容量部材４００を配置する。この高熱容量部材４００を温度波吸収面１２と温度波吸収ヒータ１２０との間（特に、温度波吸収面１２と、温度波吸収ヒータ１２０の発熱体１２１との間）に配置することにより、温度波吸収ヒータ１２０の出力の大きな変化によって当該温度波吸収面１２の温度が急激に変化することを効果的に防止することができる。したがって、試験体１０の温度波吸収面１２の温度を所定の一定値又はその極近傍に維持することができ、高い精度で当該試験体１０の熱拡散率を測定することができる。 Therefore, in the present invention, the high heat capacity member 400 having a heat capacity larger than the heat capacity of the covering 122 of the temperature wave absorption heater 120 is disposed between the temperature wave absorption surface 12 of the test body 10 and the temperature wave absorption heater 120. To do. By disposing the high heat capacity member 400 between the temperature wave absorption surface 12 and the temperature wave absorption heater 120 (particularly between the temperature wave absorption surface 12 and the heating element 121 of the temperature wave absorption heater 120), the temperature is increased. It is possible to effectively prevent a sudden change in the temperature of the temperature wave absorption surface 12 due to a large change in the output of the wave absorption heater 120. Therefore, the temperature of the temperature wave absorption surface 12 of the test body 10 can be maintained at a predetermined constant value or the vicinity thereof, and the thermal diffusivity of the test body 10 can be measured with high accuracy.
　具体的に、本方法においては、例えば、温度波吸収面１２と温度波吸収ヒータ１２０との間に高熱容量部材４００を配置して、当該温度波吸収面１２の温度を所定値±１℃の範囲内に維持した状態で、第一温度波Ｔ１及び第二温度波Ｔ２を測定する。この場合、温度波吸収面１２の温度を、所定値±０．５℃の範囲内に維持することが好ましく、所定値±０．１℃の範囲内に維持することがより好ましい。 Specifically, in this method, for example, the high heat capacity member 400 is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, and the temperature of the temperature wave absorption surface 12 is set to a predetermined value ± 1 ° C. The first temperature wave T1 and the second temperature wave T2 are measured while being maintained within the range. In this case, the temperature of the temperature wave absorbing surface 12 is preferably maintained within a range of a predetermined value ± 0.5 ° C, and more preferably maintained within a range of a predetermined value ± 0.1 ° C.
　高熱容量部材４００の熱容量は、温度波吸収ヒータ１２０の被覆材１２２の熱容量より大きければ特に限られないが、例えば、当該被覆材１２２の熱容量の２倍以上であることが好ましく、５倍以上であることがより好ましい。 The heat capacity of the high heat capacity member 400 is not particularly limited as long as it is larger than the heat capacity of the covering material 122 of the temperature wave absorption heater 120. For example, the heat capacity of the high heat capacity member 400 is preferably twice or more than the heat capacity of the covering material 122. More preferably.
　なお、温度波吸収ヒータ１２０は、発熱体１２１と被覆材１２２とを有するヒータであれば特に限られないが、例えば、好ましくは電熱ヒータである。発熱体１２１は、例えば、ニクロム線等の電熱線である。被覆材１２２は、例えば、アルミナ等の無機材料又はステンレス等の金属材料である。 The temperature wave absorption heater 120 is not particularly limited as long as it is a heater having a heating element 121 and a covering material 122, but is preferably an electric heater, for example. The heating element 121 is a heating wire such as a nichrome wire, for example. The covering material 122 is, for example, an inorganic material such as alumina or a metal material such as stainless steel.
　また、高熱容量部材４００の熱容量は、例えば、温度波吸収ヒータ１２０の被覆材１２２の熱容量より大きく、且つ５０Ｊ／Ｋ以上、好ましくは１００Ｊ／Ｋ以上であることとしてもよい。この場合、より高い精度で試験体１０の熱拡散率を測定することができる。 Moreover, the heat capacity of the high heat capacity member 400 may be, for example, larger than the heat capacity of the covering material 122 of the temperature wave absorption heater 120 and 50 J / K or more, preferably 100 J / K or more. In this case, the thermal diffusivity of the specimen 10 can be measured with higher accuracy.
　すなわち、例えば、試験体１０の周期加熱面１１から温度波吸収面１２に比較的大きな振幅を有する温度波が到達する場合（例えば、試験体１０の厚さが比較的小さい場合）、第三温度センサ３３０により測定される温度に基づき温度波吸収ヒータ１２０の出力を適切に制御して温度波吸収面１２の温度を所定の一定値に維持することは容易ではない。 That is, for example, when a temperature wave having a relatively large amplitude reaches the temperature wave absorbing surface 12 from the periodic heating surface 11 of the test body 10 (for example, when the thickness of the test body 10 is relatively small), the third temperature It is not easy to appropriately control the output of the temperature wave absorption heater 120 based on the temperature measured by the sensor 330 and maintain the temperature of the temperature wave absorption surface 12 at a predetermined constant value.
　この場合、温度波吸収面１２と温度波吸収ヒータ１２０との間に熱容量が比較的大きい（５０Ｊ／Ｋ以上又は１００Ｊ／Ｋ以上）高熱容量部材４００を配置することにより、温度波吸収面１２に到達した温度波を効果的に減衰させて、その振幅を効果的に低減させることができ、温度波吸収面１２の温度を所定の一定値となるよう調節することがより容易になる。 In this case, by disposing a high heat capacity member 400 having a relatively large heat capacity (50 J / K or more or 100 J / K or more) between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, the temperature wave absorption surface 12 is provided. The reached temperature wave can be effectively attenuated and the amplitude thereof can be effectively reduced, and it becomes easier to adjust the temperature of the temperature wave absorption surface 12 to a predetermined constant value.
　高熱容量部材４００の形状は、当該高熱容量部材４００を試験体１０の温度波吸収面１２と温度波吸収ヒータ１２０との間に配置できれば特に限られないが、例えば、平板状であることが好ましい。 The shape of the high heat capacity member 400 is not particularly limited as long as the high heat capacity member 400 can be disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120 of the test body 10. For example, a plate shape is preferable. .
　高熱容量部材４００を構成する材料は、上述のような比較的大きな熱容量を有するものであれば特に限られないが、例えば、セラミックス（例えば、アルミナ）、セメント、ガラス等の無機材料、ステンレス等の金属材料及びプラスチック等の有機材料からなる群より選択される１つ以上であることとしてもよい。また、比較的高い温度（例えば、７００～１５００℃又は８００～１５００℃）で熱拡散率を測定する場合には、当該測定温度で使用可能な耐熱性を有する材料から構成される高熱容量部材４００を使用する。具体的に、この場合、無機材料又は金属材料から構成される高熱容量部材４００を使用することが好ましい。 The material constituting the high heat capacity member 400 is not particularly limited as long as it has a relatively large heat capacity as described above. For example, inorganic materials such as ceramics (for example, alumina), cement, glass, stainless steel, etc. It may be one or more selected from the group consisting of organic materials such as metal materials and plastics. Further, when the thermal diffusivity is measured at a relatively high temperature (for example, 700 to 1500 ° C. or 800 to 1500 ° C.), the high heat capacity member 400 made of a heat-resistant material that can be used at the measurement temperature. Is used. Specifically, in this case, it is preferable to use a high heat capacity member 400 made of an inorganic material or a metal material.
　なお、第三温度センサ３３０は、温度波吸収ヒータ１２０と温度波吸収面１２との間において、温度波吸収面ヒータ１２０と接触することなく配置されることとしてもよい。この場合、第三温度センサ３３０は、温度波吸収ヒータ１２０と接触することなく、高熱容量部材４００と接触して配置されることとしてもよい。これらの場合には、第三温度センサ３３０による、高熱容量部材４００の温度又は当該温度に対応する温度の測定結果に基づいて、温度波吸収面１２の温度を所定の一定値又はその極近傍に効果的に調節することができる。 The third temperature sensor 330 may be arranged between the temperature wave absorption heater 120 and the temperature wave absorption surface 12 without contacting the temperature wave absorption surface heater 120. In this case, the third temperature sensor 330 may be disposed in contact with the high heat capacity member 400 without contacting the temperature wave absorbing heater 120. In these cases, based on the measurement result of the temperature of the high heat capacity member 400 by the third temperature sensor 330 or the temperature corresponding to the temperature, the temperature of the temperature wave absorbing surface 12 is set to a predetermined constant value or the vicinity thereof. Can be adjusted effectively.
　また、図３に示すように、本装置１００は、温度波吸収面１２と温度波吸収ヒータ１２０との間に形成され高熱容量部材４００で囲まれた隙間５００に配置された第三温度センサ３３０を有することとしてもよく、本方法においては、温度波吸収面１２と温度波吸収ヒータ１２０との間に高熱容量部材４００を配置するとともに、当該温度波吸収面１２と当該温度波吸収ヒータ１２０との間に形成され当該高熱容量部材４００で囲まれた隙間５００に、当該温度波吸収面１２の温度を測定するための温度センサ（第三温度センサ３３０）を配置した状態で、第一温度波Ｔ１及び第二温度波Ｔ２を測定することとしてもよい。 In addition, as shown in FIG. 3, the apparatus 100 includes a third temperature sensor 330 that is disposed in a gap 500 that is formed between the temperature wave absorbing surface 12 and the temperature wave absorbing heater 120 and surrounded by the high heat capacity member 400. In this method, the high heat capacity member 400 is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, and the temperature wave absorption surface 12, the temperature wave absorption heater 120, In the state where the temperature sensor (the third temperature sensor 330) for measuring the temperature of the temperature wave absorbing surface 12 is disposed in the gap 500 formed between and surrounded by the high heat capacity member 400, the first temperature wave It is good also as measuring T1 and 2nd temperature wave T2.
　この場合、第三温度センサ３３０による、高熱容量部材４００の温度又は当該温度に対応する温度の測定結果に基づいて、温度波吸収面１２の温度を所定の一定値又はその極近傍により効果的に調節することができる。 In this case, based on the measurement result of the temperature of the high heat capacity member 400 or the temperature corresponding to the temperature by the third temperature sensor 330, the temperature of the temperature wave absorption surface 12 is more effectively set to a predetermined constant value or the vicinity thereof. Can be adjusted.
　第三温度センサ３３０が配置される隙間５００は、当該第三温度センサ３３０を収容できる空間が形成されていれば特に限られないが、例えば、高熱容量部材４００の表面に形成された、当該第三温度センサ３３０を収容できる切り欠き又は溝であることとしてもよく、温度波吸収面１２と温度波吸収ヒータ１２０との間に配置された２つ以上の高熱容量部材４００の間に形成される隙間であることとしてもよい。 The gap 500 in which the third temperature sensor 330 is disposed is not particularly limited as long as a space capable of accommodating the third temperature sensor 330 is formed. For example, the gap 500 formed on the surface of the high heat capacity member 400 It is good also as a notch or a groove | channel which can accommodate the three temperature sensor 330, and is formed between the two or more high heat capacity members 400 arrange | positioned between the temperature wave absorption surface 12 and the temperature wave absorption heater 120. It may be a gap.
　温度波吸収面１２と温度波吸収ヒータ１２０との間に形成された隙間５００において、第三温度センサ３３０は、温度波吸収面ヒータ１２０と接触することなく配置されることとしてもよい。また、第三温度センサ３３０は、温度波吸収ヒータ１２０と接触することなく、高熱容量部材４００と接触して、上記隙間５００に配置されることとしてもよい。 In the gap 500 formed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, the third temperature sensor 330 may be arranged without contacting the temperature wave absorption surface heater 120. The third temperature sensor 330 may be disposed in the gap 500 in contact with the high heat capacity member 400 without contacting the temperature wave absorbing heater 120.
　これらの場合、第三温度センサ３３０による、高熱容量部材４００の温度又は当該温度に対応する温度の測定結果に基づいて、温度波吸収面１２の温度を所定の一定値又はその極近傍により効果的に調節することができる。 In these cases, based on the measurement result of the temperature of the high heat capacity member 400 or the temperature corresponding to the temperature by the third temperature sensor 330, the temperature of the temperature wave absorbing surface 12 is more effectively set to a predetermined constant value or the vicinity thereof. Can be adjusted to.
　また、温度波吸収面１２と温度波吸収ヒータ１２０との間に高熱容量部材４００を配置した状態で、試験体１０の周期加熱面１１から当該温度波吸収面１２に向けて、周期が比較的短い（例えば、２０分以下、より具体的には、１分～２０分）温度波を伝播させて、当該試験体１０の熱拡散率を測定することとしてもよい。高熱容量部材４００を配置することによる効果は、温度波の周期が比較的短い場合に特に顕著になる。 Further, in a state where the high heat capacity member 400 is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, the cycle is relatively from the periodic heating surface 11 of the test body 10 toward the temperature wave absorption surface 12. The thermal diffusivity of the specimen 10 may be measured by propagating a short temperature wave (for example, 20 minutes or less, more specifically, 1 minute to 20 minutes). The effect of disposing the high heat capacity member 400 is particularly remarkable when the period of the temperature wave is relatively short.
　また、温度波吸収面１２と温度波吸収ヒータ１２０との間に高熱容量部材４００を配置した状態で、比較的高い温度（例えば、７００℃以上、又は８００℃以上）で、試験体１０の熱拡散率を測定することとしてもよい。高熱容量部材４００を配置することによる効果は、測定温度が比較的高い場合に特に顕著になる。 Further, with the high heat capacity member 400 disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120, the heat of the test body 10 at a relatively high temperature (eg, 700 ° C. or more, or 800 ° C. or more). The diffusivity may be measured. The effect of disposing the high heat capacity member 400 is particularly remarkable when the measurement temperature is relatively high.
　また、例えば、試験体１０の周期加熱面１１に温度波を与える周期加熱ヒータ１１０で発生する温度波の振幅が所定値±１０℃の範囲内であり、当該周期加熱ヒータ１１０と接触しているのは当該試験体１０と補助ヒータ１５０のみであり、当該試験体１０の周期加熱面１１と対向する当該周期加熱ヒータ１１０の表面の面積が、当該周期加熱面１１の面積±２０％の範囲内であることが好ましい。 Further, for example, the amplitude of the temperature wave generated by the periodic heater 110 that applies a temperature wave to the periodic heating surface 11 of the test body 10 is within a predetermined value ± 10 ° C., and is in contact with the periodic heater 110. Are only the test body 10 and the auxiliary heater 150, and the area of the surface of the periodic heater 110 facing the periodic heating surface 11 of the test body 10 is within the range of ± 20% of the area of the periodic heating surface 11. It is preferable that
　また、試験体１０、周期加熱ヒータ１１０、温度波吸収ヒータ１２０、補助ヒータ１５０等を含む測定部を収容する筐体１９０、当該測定部を取り囲むヒータ、壁材等の放射率が０．１以上であり、これらの熱容量が５０Ｊ／Ｋ以上であることが好ましい。 Also, the emissivity of the casing 190 that houses the measurement unit including the test body 10, the periodic heater 110, the temperature wave absorption heater 120, the auxiliary heater 150, the heater surrounding the measurement unit, the wall material, etc. is 0.1 or more. These heat capacities are preferably 50 J / K or more.
　次に、本実施形態に係る具体的な実施例について説明する。 Next, specific examples according to this embodiment will be described.
　図４には、試験体１０の温度波吸収面１２と温度波吸収ヒータ１２０との間に高熱容量部材４００を配置した場合、及び当該高熱容量部材４００を配置しない場合のそれぞれについて、当該温度波吸収面１２における温度波の振幅を理論的に検討した結果を示す。 FIG. 4 shows the temperature wave when the high heat capacity member 400 is arranged between the temperature wave absorption surface 12 of the test body 10 and the temperature wave absorption heater 120 and when the high heat capacity member 400 is not arranged. The result of having examined theoretically the amplitude of the temperature wave in the absorption surface 12 is shown.
　すなわち、高熱容量部材４００を配置した場合については、当該高熱容量部材４００の密度が３８００（ｋｇ／ｍ３）、比熱が１０００（Ｊ／ｋｇ・Ｋ）、体積が４．５×１０－５（ｍ３）（＝０．１×０．１５×０．００３）であるという条件、また、当該高熱容量部材４００を配置しない場合については、温度波吸収面１２と温度波吸収ヒータ１２０との間に形成される空気層の密度が１．０（ｋｇ／ｍ３）、比熱が１０００（Ｊ／ｋｇ・Ｋ）、体積が１．５×１０－５（ｍ３）（＝０．１×０．１５×０．０００１）であるという条件にて、コンピュータを使用した数値計算により熱伝導方程式を解いた。 That is, when the high heat capacity member 400 is arranged, the density of the high heat capacity member 400 is 3800 (kg / m 3 ), the specific heat is 1000 (J / kg · K), and the volume is 4.5 × 10 −5 ( m 3 ) (= 0.1 × 0.15 × 0.003), and in the case where the high heat capacity member 400 is not disposed, between the temperature wave absorption surface 12 and the temperature wave absorption heater 120. The density of the air layer formed in this is 1.0 (kg / m 3 ), the specific heat is 1000 (J / kg · K), and the volume is 1.5 × 10 −5 (m 3 ) (= 0.1 × 0 .15 × 0.0001), the heat conduction equation was solved by a numerical calculation using a computer.
　図４において、横軸は温度波の周期（分）を示し、縦軸は試験体１０の周期加熱面１１から温度波吸収面１２に到達する温度波の振幅θ0と、高熱容量板４００の温度振幅θ、又は温度波吸収面１２と温度波吸収ヒータ１２０との間の空気層の温度振幅θとの比（θ／θ0）を示している。また、図４では、高熱容量部材４００に対して、試験体１０から熱が三角関数的に流入してくると仮定して熱伝導方程式を解いた結果を実線で示し、当該高熱容量部材４００を配置しない場合の結果を破線で示している。 In FIG. 4, the horizontal axis indicates the period (minute) of the temperature wave, and the vertical axis indicates the amplitude θ 0 of the temperature wave reaching the temperature wave absorption surface 12 from the periodic heating surface 11 of the test body 10 and the high heat capacity plate 400. The temperature amplitude θ or the ratio (θ / θ 0 ) of the temperature amplitude θ of the air layer between the temperature wave absorbing surface 12 and the temperature wave absorbing heater 120 is shown. Further, in FIG. 4, the result of solving the heat conduction equation on the assumption that heat flows from the test body 10 into the high heat capacity member 400 in a trigonometric function is indicated by a solid line, and the high heat capacity member 400 is The result when not arranged is shown by a broken line.
　ここで、高熱容量部材４００の比熱をＣｐ、密度をρ、体積をｖ、試験体１０から当該高熱容量部材４００への熱伝達率をα、その時の伝熱面積をＳ、当該試験体１０から当該高熱容量部材４００に入る温度波をθｓ、当該高熱容量部材４００又は空気層の温度をθとすると、下記式（ＶＩ）で表される熱伝導率方程式が成立する。
Figure JPOXMLDOC01-appb-M000006
 Here, the specific heat of the high heat capacity member 400 is C p , the density is ρ, the volume is v, the heat transfer rate from the test body 10 to the high heat capacity member 400 is α, the heat transfer area at that time is S, and the test body 10 When the temperature wave entering the high heat capacity member 400 from θ s and the temperature of the high heat capacity member 400 or the air layer as θ, the thermal conductivity equation represented by the following formula (VI) is established.
Figure JPOXMLDOC01-appb-M000006
　上記式（ＶＩ）を変形すると、下記式（ＶＩＩ）を得る。
Figure JPOXMLDOC01-appb-M000007
 When the above formula (VI) is modified, the following formula (VII) is obtained.
Figure JPOXMLDOC01-appb-M000007
　ここで、Ａを下記式（ＶＩＩＩ）のように置くと、上記式（ＶＩＩ）は下記式（ＩＸ）のようになる。
Figure JPOXMLDOC01-appb-M000008
Figure JPOXMLDOC01-appb-M000009
 Here, when A is placed as in the following formula (VIII), the above formula (VII) becomes the following formula (IX).
Figure JPOXMLDOC01-appb-M000008
Figure JPOXMLDOC01-appb-M000009
　温度波θｓが下記式（Ｘ）のように表され、高熱容量部材４００又は空気層の温度θが下記（ＸＩ）のように表されるとして、当該式（Ｘ）及び当該式（ＸＩ）を上記式（ＩＸ）に代入すると、下記式（ＸＩＩ）を得る。
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000012
 Assuming that the temperature wave θ s is expressed as the following formula (X) and the temperature θ of the high heat capacity member 400 or the air layer is expressed as the following (XI), the formula (X) and the formula (XI) Is substituted into the above formula (IX) to obtain the following formula (XII).
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000012
　ここで、時間ｔによらず上記式（ＩＸ）が成立する場合には、下記式（ＸＩＩＩ）及び下記式（ＸＩＶ）が成立する。
Figure JPOXMLDOC01-appb-M000013
Figure JPOXMLDOC01-appb-M000014
 Here, when the above formula (IX) holds regardless of the time t, the following formula (XIII) and the following formula (XIV) hold.
Figure JPOXMLDOC01-appb-M000013
Figure JPOXMLDOC01-appb-M000014
　上記式（ＸＩＩＩ）及び上記式（ＸＩＶ）より、下記式（ＸＶ）及び下記式（ＸＶＩ）を得る。
Figure JPOXMLDOC01-appb-M000015
Figure JPOXMLDOC01-appb-M000016
 From the above formula (XIII) and the above formula (XIV), the following formula (XV) and the following formula (XVI) are obtained.
Figure JPOXMLDOC01-appb-M000015
Figure JPOXMLDOC01-appb-M000016
　さらに、上記式（ＸＶ）を変形すると、下記式（ＸＶＩＩ）を得る。
Figure JPOXMLDOC01-appb-M000017
 Further, when the formula (XV) is modified, the following formula (XVII) is obtained.
Figure JPOXMLDOC01-appb-M000017
　したがって、上記式（ＸＶＩＩ）を使って、試験体１０から高熱容量部材４００又は空気層に温度波が伝播した際の振幅比（θ／θ0）を求めることができる。 Therefore, the amplitude ratio (θ / θ 0 ) when the temperature wave propagates from the test body 10 to the high heat capacity member 400 or the air layer can be obtained using the above formula (XVII).
　図４において、温度波の振幅比θ/θ0が小さいほど（すなわち、振幅の減衰が大きいほど）、温度波吸収ヒータ１２０の出力が小さくなるため、温度波吸収面１２の温度を所定の一定値に調節しやすいことになる。 In FIG. 4, the smaller the temperature wave amplitude ratio θ / θ 0 (ie, the greater the amplitude attenuation), the smaller the output of the temperature wave absorbing heater 120, so the temperature of the temperature wave absorbing surface 12 is kept at a predetermined constant value. It will be easy to adjust to the value.
　すなわち、例えば、周期の短い温度波を使用した測定では、短い時間間隔で温度波吸収ヒータ１２０の出力を制御しなければならない。このため、温度波が減衰されないまま温度波吸収面１２に到達すると、温度波吸収ヒータ１２０は短時間で出力を急激に増加させることになり、その結果、温度波吸収面１２の温度がオーバーシュートし、当該温度波吸収面１２における温度を所定の一定値に維持することが難しくなる。 That is, for example, in measurement using a temperature wave with a short cycle, the output of the temperature wave absorption heater 120 must be controlled at a short time interval. For this reason, when the temperature wave reaches the temperature wave absorption surface 12 without being attenuated, the temperature wave absorption heater 120 rapidly increases the output in a short time. As a result, the temperature of the temperature wave absorption surface 12 overshoots. And it becomes difficult to maintain the temperature in the said temperature wave absorption surface 12 at a predetermined fixed value.
　この点、図４から、高熱容量部材４００を配置しない場合には（破線）、周期の全範囲で温度波は全く減衰しない（振幅比は一定）という結果が得られた。一方、高熱容量部材４００を配置する場合には（実線）、特に、周期が２０分以下の範囲で短くなるにつれて、振幅比が急速に小さくなるという結果が得られた。 From this point, it can be seen from FIG. 4 that when the high heat capacity member 400 is not arranged (broken line), the temperature wave is not attenuated at all in the entire range of the period (the amplitude ratio is constant). On the other hand, in the case where the high heat capacity member 400 is arranged (solid line), in particular, the result is that the amplitude ratio decreases rapidly as the period becomes shorter in a range of 20 minutes or less.
　すなわち、高熱容量部材４００を配置することにより、周期の短い温度波を使用する測定においても温度波吸収面１２における温度を所定の一定値に維持しやすくなることが確認された。 That is, it was confirmed that the temperature at the temperature wave absorbing surface 12 can be easily maintained at a predetermined constant value even in the measurement using the temperature wave with a short cycle by arranging the high heat capacity member 400.
　図３に示すように高熱容量部材４００を有する本装置１００を使用する本方法により試験体１０の熱拡散率を測定し、さらに当該熱拡散率から当該試験体１０の熱伝導率を求めた。 As shown in FIG. 3, the thermal diffusivity of the test specimen 10 was measured by this method using the apparatus 100 having the high heat capacity member 400, and the thermal conductivity of the test specimen 10 was obtained from the thermal diffusivity.
　高熱容量部材４００としては、温度波吸収ヒータ１２０の被覆材１２２の熱容量の約１０倍の熱容量（約１７０Ｊ／Ｋ）を有するアルミナ製の平板（７３ｍｍ×１００ｍｍ、厚さ３０ｍｍ）２枚を使用した。 As the high heat capacity member 400, two alumina flat plates (73 mm × 100 mm, thickness 30 mm) having a heat capacity (about 170 J / K) that is about 10 times the heat capacity of the covering material 122 of the temperature wave absorption heater 120 were used. .
　周期加熱ヒータ１１０、温度波吸収ヒータ１２０及び周囲加熱ヒータ１３０としては、金属製の電熱線からなる発熱体１２１と、当該発熱体１２１を被覆するセラミック製の被覆材１２２とを有する電熱ヒータを使用した。 As the periodic heater 110, the temperature wave absorption heater 120, and the ambient heater 130, an electric heater having a heating element 121 made of a metal heating wire and a ceramic covering material 122 that covers the heating element 121 is used. did.
　第一温度センサ３１０、第二温度センサ３２０、第三温度センサ３３０及び第四温度センサ３４０としては、直径が試験体１０の厚さの１０分の１以下であり、且つ高熱容量部材４００の厚さの１０分の１以下である円筒状の筐体を有する熱電対を使用した。 As the first temperature sensor 310, the second temperature sensor 320, the third temperature sensor 330, and the fourth temperature sensor 340, the diameter is one tenth or less of the thickness of the test body 10 and the thickness of the high heat capacity member 400. A thermocouple having a cylindrical casing that is one tenth or less of that is used.
　より具体的に、図３に示すように、温度波吸収面１２と温度波吸収ヒータ１２０との間に、隙間５００を空けて２枚のアルミナ板からなる高熱容量部材４００を配置するとともに、当該２枚のアルミナ板に挟まれた当該隙間５００に、熱電対からなる第三温度センサ３３０を配置した。 More specifically, as shown in FIG. 3, a high heat capacity member 400 made of two alumina plates is disposed between the temperature wave absorption surface 12 and the temperature wave absorption heater 120 with a gap 500 therebetween. A third temperature sensor 330 made of a thermocouple was disposed in the gap 500 sandwiched between two alumina plates.
　また、図示はしていないが、周期加熱面１１に溝を形成して当該溝内に第一温度センサ３１０を配置するとともに、当該周期加熱面１１と周期加熱ヒータ１１０との間（当該第一温度センサ３１０と当該周期加熱ヒータ１１０との間）に、無機繊維製のフリースを配置した。 Although not shown, a groove is formed in the periodic heating surface 11 and the first temperature sensor 310 is arranged in the groove, and between the periodic heating surface 11 and the periodic heater 110 (the first heater). Between the temperature sensor 310 and the periodical heater 110), an inorganic fiber fleece was disposed.
　また、周囲ヒータ１３０は、予め出力を所定値±０．０５％の範囲に制限して使用した。また、周期加熱面１１と、試験体１０の内部の所定位置１４とで測定された温度波は、その一周期分の測定値を最小二乗法により三角関数に近似し、当該近似により得られた温度波の位相差から、当該試験体１０の熱拡散率を測定した。 Also, the ambient heater 130 was used with its output limited in advance to a predetermined value ± 0.05%. Further, the temperature wave measured at the periodic heating surface 11 and the predetermined position 14 inside the test body 10 is obtained by approximating the measured value for one period to a trigonometric function by the least square method, and obtaining the approximation. From the phase difference of the temperature wave, the thermal diffusivity of the specimen 10 was measured.
　まず、試験体１０としてアルミナ－シリカ系繊維質断熱材（１５０ｍｍ×１００ｍｍ、厚さ３０ｍｍ）１枚を使用し、当該試験体１０の１００℃、２００℃、４００℃、６００℃、８００℃、１０００℃、１２００℃、１４００℃及び１５００℃における熱拡散率を測定し、当該熱拡散率から熱伝導率を求めた。周期加熱ヒータ１１０で発生させた温度波の振幅は３℃であり、周期は６０分であった。試験体１０の温度波吸収面１２の温度は、所定値±０．０５℃の範囲内に維持された。また、試験体１０を伝播する、連続する３周期分の温度波において、各１周期分の温度波の振幅の中心温度の平均値と、当該３周期分の温度波の振幅の中心温度の平均値との差分は、±２℃以内であった。また、比較のため、この試験体１０の熱伝導率をＧＨＰ法によっても測定した。 First, an alumina-silica fiber heat insulating material (150 mm × 100 mm, thickness 30 mm) was used as the test body 10, and the test body 10 was tested at 100 ° C., 200 ° C., 400 ° C., 600 ° C., 800 ° C., 1000 The thermal diffusivity was measured at 1,200, 1,400, and 1500 ° C., and the thermal conductivity was determined from the thermal diffusivity. The amplitude of the temperature wave generated by the periodic heater 110 was 3 ° C., and the period was 60 minutes. The temperature of the temperature wave absorbing surface 12 of the test body 10 was maintained within a range of a predetermined value ± 0.05 ° C. Moreover, in the temperature wave for three continuous periods which propagates through the test body 10, the average value of the center temperature of the amplitude of the temperature wave for one period and the average of the center temperature of the amplitude of the temperature wave for the three periods The difference from the value was within ± 2 ° C. For comparison, the thermal conductivity of the specimen 10 was also measured by the GHP method.
　また、試験体１０として繊維補強セメント板（１５０ｍｍ×１００ｍｍ、厚さ２０ｍｍ）２枚を使用し、当該試験体１０の１００℃、３００℃及び５００℃における熱拡散率を測定し、当該熱拡散率から熱伝導率を求めた。周期加熱ヒータ１１０で発生させた温度波の振幅は２℃であり、周期は６０分であった。試験体１０の温度波吸収面１２の温度は、所定値±０．０５℃の範囲内に維持された。また、試験体１０を伝播する、連続する３周期分の温度波において、各１周期分の温度波の振幅の中心温度の平均値と、当該３周期分の温度波の振幅の中心温度の平均値との差分は、±２℃以内であった。また、比較のため、この試験体１０の熱伝導率をＧＨＰ法によっても測定した。 In addition, two fiber reinforced cement plates (150 mm × 100 mm, thickness 20 mm) are used as the test body 10, the thermal diffusivities of the test body 10 at 100 ° C., 300 ° C., and 500 ° C. are measured, and the thermal diffusivity is measured. From this, the thermal conductivity was determined. The amplitude of the temperature wave generated by the periodic heater 110 was 2 ° C., and the period was 60 minutes. The temperature of the temperature wave absorbing surface 12 of the test body 10 was maintained within a range of a predetermined value ± 0.05 ° C. Moreover, in the temperature wave for three continuous periods which propagates through the test body 10, the average value of the center temperature of the amplitude of the temperature wave for one period and the average of the center temperature of the amplitude of the temperature wave for the three periods The difference from the value was within ± 2 ° C. For comparison, the thermal conductivity of the specimen 10 was also measured by the GHP method.
　また、試験体１０としてステンレス（ＳＵＳ）板（１５０ｍｍ×１００ｍｍ、厚さ５０ｍｍ）を使用し、当該試験体１０の１１０℃における熱拡散率を測定し、当該熱拡散率から熱伝導率を求めた。周期加熱ヒータ１１０で発生させた温度波の振幅は５℃であり、周期は５分であった。試験体１０の温度波吸収面１２の温度は、所定値±０．０５℃の範囲内に維持された。また、試験体１０を伝播する、連続する３周期分の温度波において、各１周期分の温度波の振幅の中心温度の平均値と、当該３周期分の温度波の振幅の中心温度の平均値との差分は、±２℃以内であった。 Moreover, a stainless steel (SUS) plate (150 mm × 100 mm, thickness 50 mm) was used as the test body 10, the thermal diffusivity of the test body 10 at 110 ° C. was measured, and the thermal conductivity was obtained from the thermal diffusivity. . The amplitude of the temperature wave generated by the periodic heater 110 was 5 ° C., and the period was 5 minutes. The temperature of the temperature wave absorbing surface 12 of the test body 10 was maintained within a range of a predetermined value ± 0.05 ° C. Moreover, in the temperature wave for three continuous periods which propagates through the test body 10, the average value of the center temperature of the amplitude of the temperature wave for one period and the average of the center temperature of the amplitude of the temperature wave for the three periods The difference from the value was within ± 2 ° C.
　図５、図６及び図７に、アルミナ－シリカ系繊維質断熱材、繊維補強セメント板及びＳＵＳ板の熱伝導率を測定した結果をそれぞれ示す。図５～図７において、横軸は熱伝導率を測定した温度（℃）（周期加熱面１１における温度波の振幅の中心温度と、温度波吸収面１２の所定の一定温度との算術平均値）を示し、縦軸は各温度で測定された熱伝導率（Ｗ／（ｍ・Ｋ））を示す。 FIG. 5, FIG. 6 and FIG. 7 show the results of measuring the thermal conductivity of the alumina-silica fiber heat insulating material, the fiber reinforced cement board and the SUS board, respectively. 5 to 7, the horizontal axis represents the temperature (° C.) at which the thermal conductivity is measured (the arithmetic average value of the center temperature of the temperature wave amplitude on the periodic heating surface 11 and the predetermined constant temperature on the temperature wave absorption surface 12). The vertical axis indicates the thermal conductivity (W / (m · K)) measured at each temperature.
　図５及び図６において、丸印は周期加熱法を使用した本方法で測定した結果を示し、四角印はＧＨＰ法で測定した結果を示す。図７において、丸印は周期加熱法を使用した本方法で測定した結果を示し、実線は、文献値（新編熱物性ハンドブック　日本熱物性学会編　ｐ．２１３（２００８年３月２５日　第１版発行））を示す。 5 and 6, circles indicate the results measured by this method using the periodic heating method, and square marks indicate the results measured by the GHP method. In FIG. 7, circles indicate the results measured by this method using the periodic heating method, and solid lines indicate literature values (new thermophysical handbook, edited by the Japan Society for Thermophysical Properties, p. 213 (March 25, 2008, 1st Edition). Issue)).
　図５及び図６に示すように、本装置１００を使用した本方法による測定結果は、ＧＨＰ法による測定結果とほぼ一致した。さらに、図７に示すように、本装置１００を使用した本方法による測定結果は、文献値とも一致していた。すなわち、本装置１００を使用した本方法によれば、広い温度範囲において高い精度で熱拡散率及び熱伝導率を測定できることが確認された。 As shown in FIG. 5 and FIG. 6, the measurement result by this method using the present apparatus 100 almost coincided with the measurement result by the GHP method. Furthermore, as shown in FIG. 7, the measurement result by this method using this apparatus 100 was in agreement with the literature value. That is, according to the method using the apparatus 100, it was confirmed that the thermal diffusivity and the thermal conductivity can be measured with high accuracy in a wide temperature range.
　１０　試験体、１１　周期加熱面、１２　温度波吸収面、１３　側面、１４　試験体内部の所定位置、１００　熱拡散率測定装置、１１０　周期加熱ヒータ、１２０　温度波吸収ヒータ、１２１　発熱体、１２２　被覆材、１３０　周囲ヒータ、１４０　冷却装置、１５０　補助ヒータ、１６０，１７０　断熱材、１８０　金属板、１９０　筐体、２００　直流電源、２１０　ファンクションジェネレータ、３１０　第一温度センサ、３２０　第二温度センサ、３３０　第三温度センサ、３４０　第四温度センサ、４００　高熱容量部材、５００　隙間。 10 specimens, 11 periodic heating surfaces, 12 temperature wave absorbing surfaces, 13 side surfaces, 14 predetermined positions inside the specimen, 100 thermal diffusivity measuring device, 110 periodic heating heaters, 120 temperature wave absorbing heaters, 121 heating elements, 122 coatings Material, 130 ambient heater, 140 cooling device, 150 auxiliary heater, 160, 170 heat insulating material, 180 metal plate, 190 housing, 200 DC power supply, 210 function generator, 310 first temperature sensor, 320 second temperature sensor, 330th Three temperature sensor, 340, fourth temperature sensor, 400, high heat capacity member, 500 gap.

Claims (5)

  1. 　周期加熱法により熱拡散率を測定する方法であって、
    　試験体の周期加熱面から温度波吸収面に向けて温度波を伝播させること；
    　前記周期加熱面における第一温度波を測定すること；
    　前記周期加熱面と前記温度波吸収面との間の前記試験体の内部の所定位置における第二温度波を測定すること；
    　前記第一温度波と前記第二温度波との振幅比又は位相差から前記試験体の熱拡散率を得ること；
    　を含み、
    　前記温度波吸収面と対向する位置に、前記温度波吸収面の温度を所定の一定値に維持するための、発熱体と前記発熱体の前記温度波吸収面側を覆う被覆材とを有する温度波吸収ヒータを配置し、
    　前記温度波吸収面と前記温度波吸収ヒータとの間に、前記温度波吸収ヒータの前記被覆材の熱容量より大きい熱容量を有する高熱容量部材を配置した状態で、前記第一温度波及び前記第二温度波を測定する
    　ことを特徴とする方法。     A method for measuring thermal diffusivity by a periodic heating method,
    Propagating the temperature wave from the periodic heating surface of the specimen toward the temperature wave absorption surface;
    Measuring a first temperature wave at the periodic heating surface;
    Measuring a second temperature wave at a predetermined position inside the specimen between the periodic heating surface and the temperature wave absorption surface;
    Obtaining the thermal diffusivity of the specimen from the amplitude ratio or phase difference between the first temperature wave and the second temperature wave;
    Including
    A temperature having a heating element and a covering material covering the temperature wave absorption surface side of the heating element for maintaining the temperature of the temperature wave absorption surface at a predetermined constant value at a position facing the temperature wave absorption surface. A wave absorption heater,
    In a state where a high heat capacity member having a heat capacity larger than the heat capacity of the covering material of the temperature wave absorption heater is disposed between the temperature wave absorption surface and the temperature wave absorption heater, the first temperature wave and the second temperature wave A method characterized by measuring a temperature wave.
  2. 　前記温度波吸収面と前記温度波吸収ヒータとの間に前記高熱容量部材を配置して、前記温度波吸収面の温度を所定値±１℃の範囲内に維持した状態で、前記第一温度波及び前記第二温度波を測定する
    　ことを特徴とする請求項１に記載の方法。     In the state where the high heat capacity member is disposed between the temperature wave absorption surface and the temperature wave absorption heater and the temperature of the temperature wave absorption surface is maintained within a range of a predetermined value ± 1 ° C. The method of claim 1, wherein a wave and the second temperature wave are measured.
  3. 　前記温度波吸収面と前記温度波吸収ヒータとの間に前記高熱容量部材を配置するとともに、前記温度波吸収面と前記温度波吸収ヒータとの間に形成され前記高熱容量部材で囲まれた隙間に、前記温度波吸収面の温度を測定するための温度センサを配置した状態で、前記第一温度波及び前記第二温度波を測定する
    　ことを特徴とする請求項１又は２に記載の方法。     The high heat capacity member is disposed between the temperature wave absorption surface and the temperature wave absorption heater, and a gap formed between the temperature wave absorption surface and the temperature wave absorption heater and surrounded by the high heat capacity member The method according to claim 1, wherein the first temperature wave and the second temperature wave are measured in a state where a temperature sensor for measuring the temperature of the temperature wave absorption surface is arranged. .
  4. 　周期加熱法により熱拡散率を測定するための装置であって、
    　試験体の周期加熱面から温度波吸収面に向けて温度波を伝播させるために前記周期加熱面に対向して配置される周期加熱ヒータ；
    　前記試験体の前記温度波吸収面の温度を所定の一定値に維持するために前記温度波吸収面に対向して配置される、発熱体と前記発熱体の前記温度波吸収面側を覆う被覆材とを有する温度波吸収ヒータ；
    　前記周期加熱面における第一温度波を測定するための第一温度センサ；
    　前記周期加熱面と前記温度波吸収面との間の前記試験体の内部の所定位置における第二温度波を測定するための第二温度センサ；
    　前記温度波吸収面の温度を測定するための第三温度センサ；及び
    　前記試験体の前記温度波吸収面と前記温度波吸収ヒータとの間に配置される、前記温度波吸収ヒータの前記被覆材の熱容量より大きい熱容量を有する高熱容量部材；
    　を有する
    　ことを特徴とする装置。     An apparatus for measuring thermal diffusivity by a periodic heating method,
    A periodic heater disposed to face the periodic heating surface in order to propagate a temperature wave from the periodic heating surface of the test body toward the temperature wave absorbing surface;
    A heating element and a coating covering the temperature wave absorption surface side of the heating element, which is disposed opposite to the temperature wave absorption surface to maintain the temperature of the temperature wave absorption surface of the test body at a predetermined constant value. A temperature wave absorption heater having a material;
    A first temperature sensor for measuring a first temperature wave at the periodic heating surface;
    A second temperature sensor for measuring a second temperature wave at a predetermined position inside the specimen between the periodic heating surface and the temperature wave absorption surface;
    A third temperature sensor for measuring the temperature of the temperature wave absorption surface; and the covering material of the temperature wave absorption heater disposed between the temperature wave absorption surface of the test body and the temperature wave absorption heater. A high heat capacity member having a heat capacity greater than the heat capacity of;
    The apparatus characterized by having.
  5. 　前記温度波吸収面と前記温度波吸収ヒータとの間に形成され前記高熱容量部材で囲まれた隙間に配置された前記第三温度センサを有する
    　ことを特徴とする請求項４に記載の装置。     The apparatus according to claim 4, further comprising: the third temperature sensor disposed in a gap formed between the temperature wave absorption surface and the temperature wave absorption heater and surrounded by the high heat capacity member.
PCT/JP2014/075968 2013-09-30 2014-09-29 Method and device for measuring thermal diffusivity WO2015046545A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001174425A (en) * 1999-12-17 2001-06-29 Shimadzu Corp Heat conductivity detector
JP2002116167A (en) * 2000-10-11 2002-04-19 Nichias Corp Measuring instrument and measuring method for thermal conductivity
JP2005315762A (en) * 2004-04-30 2005-11-10 National Institute Of Advanced Industrial & Technology Thermal physical property measurement method and apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001174425A (en) * 1999-12-17 2001-06-29 Shimadzu Corp Heat conductivity detector
JP2002116167A (en) * 2000-10-11 2002-04-19 Nichias Corp Measuring instrument and measuring method for thermal conductivity
JP2005315762A (en) * 2004-04-30 2005-11-10 National Institute Of Advanced Industrial & Technology Thermal physical property measurement method and apparatus

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