JP2574802B2 - Specific heat measurement device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a specific heat measurement device, and more particularly, to a specific heat measurement device for measuring the specific heat of a solid sample having a known mass using an insulated container. It is.

[Prior Art] When measuring the specific heat of a solid substance such as a ceramic material, conventionally, for example, it has been performed as follows. First,
A cross-sectional container containing water therein and a sample of a substance whose specific heat is to be measured (hereinafter, referred to as a substance to be measured) are prepared. Next, after heating the sample to a predetermined temperature, it is poured into the water and stirred. In water, the sample exchanges heat with water and eventually reaches thermal equilibrium, so the temperature at that time (thermal equilibrium temperature) is measured. From the difference between the heated temperature of the sample (heating temperature) and the equilibrium temperature, the amount of heat released from the sample, that is, the value of the heat capacity can be known. Then, the specific heat of the sample is calculated from the heat capacity value and the previously measured mass value of the sample. For the measurement of the heat capacity at that time, for example, a water calorimeter is used.

[Problems to be Solved] However, in this conventional method, a great deal of labor and a long time are required for the stirring operation until the thermal equilibrium is reached.
There is a problem that the correction work for calculating the accurate value is troublesome.

In addition, specific heat cannot be measured for a substance that reacts with water or a substance that loses its shape when immersed in water, and there is also a problem that the temperature after heating must not exceed 100 ° C.

Therefore, an object of the present invention is to provide a specific heat measurement method and a specific heat measurement method capable of achieving a thermal equilibrium of a solid sample without performing a conventional stirring operation, and capable of measuring a specific heat of a substance affected by contact with water. It is to provide a measuring device.

It is another object of the present invention to provide a specific heat measurement device capable of heating a substance to a temperature exceeding 100 ° C.

Another object of the present invention is to provide a specific heat measuring device capable of reducing the labor required for the specific heat measuring operation and suppressing the occurrence of a measurement error.

[Means for Solving the Problems] The specific heat measurement device of the present invention is a specific heat measurement device that measures the specific heat c _1X of a solid sample whose mass m ₁₂ is known,
(A) a heat insulating container having a heat capacity of K; (b) a first measurement probe contacted with the sample in the heat insulating container; and (c) a specific heat c ₀₁ and a mass m ₀₁ in the heat insulating container. And (d) measuring the temperature of the sample via the first measurement probe and measuring the temperature of the reference material via the second measurement probe. (E)
A changeover switch for selectively connecting the second measuring probe to the temperature measuring means or the heating power supply, and a temperature t ₁₂ when the sample disposed inside the heat insulating container is thermally stabilized. Is measured using the first measuring probe and the temperature measuring means, while the second measuring probe is connected to the heating power supply by the changeover switch, and the power supply is used to transfer the reference substance outside the heat insulating container. After heating, the reference substance is accommodated inside the heat insulating container and brought into contact with the sample, and then contacted using the second measurement probe connected to the temperature measurement means by the changeover switch and the temperature measurement means. the temperature t ₁₁ of the reference material at the start was measured, further, the temperature theta ₁ when the reference material in contact with the sample has reached a thermal equilibrium first measurement Saguko,
The following relational expression is obtained by using the second measurement probe and the temperature measurement means, and using the measured values of t ₁₂ , t ₁₁ and θ ₁ thus obtained. It is further characterized in that the specific heat c _1X of the sample is calculated.

In the specific heat measurement device of the present invention, the second measurement probe includes a resistor that contacts the reference substance, and a conductor that connects the low antibody to the temperature measurement unit, and the first measurement probe includes: It is preferable that the apparatus further comprises a thermal contact that contacts the sample, and a thermocouple wire that connects the thermal contact to the temperature measuring means.

The reference material is composed of two halves, and the resistor of the second measurement probe is in contact with and sandwiched between the halves, or the resistor of the second measurement probe is inside the reference material. It is preferably buried in.

 A plurality of the second measurement probes may be provided.

[Operation] In the specific heat measurement device of the present invention, the solid sample and the solid reference material are brought into contact with each other in the heat insulating container to thermally equilibrate them, and between the start of contact and the time of thermal equilibrium, the reference material and the sample are The specific heat of the sample is measured by determining the amount of heat transferred.

Since the reference material with which the solid sample is brought into contact is the coated body, thermal equilibrium can be achieved without performing a stirring operation as in the related art. This leads to a reduction in the labor required for the specific heat measurement operation.

In addition, it is possible to measure the specific heat of a substance which is affected by contact with water, and to heat the substance to a temperature exceeding 100 ° C.

In addition, since there is no need for agitation work and internal observation of the heat insulation container between the start of contact between the reference material and the sample until the thermal equilibrium is reached, sufficient heat insulation can be maintained and measurement errors are suppressed. be able to.

Examples Examples of the present invention will be specifically described below with reference to the accompanying drawings.

First Embodiment FIGS. 1 (a) and 1 (b) are cross-sectional views showing a first embodiment of the specific heat measuring device of the present invention.

The specific heat measuring apparatus 10 of the first embodiment includes a heat insulating container 20 formed of an appropriate heat insulating material, and a reference measuring probe (second second measuring probe) used for measuring the temperature of the solid reference substance 22 inside the heat insulating container 20. Measuring the temperature of a solid sample of unknown specific heat (hereinafter, referred to as “sample to be measured”) 25 or a solid sample of known specific heat (hereinafter, referred to as “standard sample”) 23 inside the heat insulating container 20. And a temperature measuring device 30 to which the reference measuring probe 21 and the sample measuring probe 24 are electrically connected, respectively.

The reference measurement probe 21 is configured to be selectively connected to the temperature measuring device 30 or the heating power supply 32 by the changeover switch 31. When measuring the temperature of the solid reference material 22, the reference measurement probe 21 is connected to a temperature measuring device 30, and when heating the solid reference device 22, it is connected to a heating power supply 32.

As shown clearly in FIG. 3, the reference measurement probe 21 includes a resistance wire (for example, platinum wire) 21 brought into contact with the reference material 22.
a, and two conductive wires 21b and 21c each having one end connected to both ends of the resistance wire 21a. The other ends of the conductors 21b and 21c are connected to corresponding terminals of the changeover switch 31, respectively. At the time of temperature measurement, heat data detected by the resistance wire 21a is transmitted to the temperature measuring device 30 via the conductors 21b and 21c and the changeover switch 31, and the temperature value of the reference substance 22 is calculated based on the data. During heating, the changeover switch 31 and the conductor 21
Appropriate voltage is applied to the resistance wire 21a from the power supply 32 via b and 21c, whereby the reference substance 22 is heated.

The sample measurement probe 24 includes a hot junction 24a and two thermocouple wires 24.
b and 24c to form a thermocouple. Hot junction
24a is brought into contact with the measured sample 25 or the standard sample 23 at the time of measurement. One end of each of the thermocouple wires 24b and 24c is connected to the thermal contact 24a, and the other end is connected to a terminal corresponding to the temperature measuring device 30. The heat data detected at the hot junction 24a is transmitted to the temperature measuring device 30 through the thermocouple wires 24b and 24c, and the temperature value of the sample 25 or the standard sample 23 is calculated based on the data.

DUT 25, the mass m ₁₂ is known, the specific heat c _1X is formed from a piece of unknown substances (e.g., ceramic).

Standard sample 23, both the specific heat c ₀₂ and the mass m ₀₂ is a known suitable material (e.g., quartz glass or metal) is formed from a piece of. The standard sample 23 is used to determine the heat capacity K of the heat insulating container 20.

The reference substance 22 is an appropriate substance whose specific heat _c01 and mass _m01 are both known, and for example, a good heat conductor such as copper or silver is used. Reference substance 22 is the specific heat of the sample to be measured.
c Used as a reference when calculating the heat capacity K of _1X and the heat insulating container 20.

Next, using the specific heat measurement device 10 having the above configuration,
A method for measuring the unknown specific heat ck _1X of the sample 25 to be measured will be described. In this method, first, the heat capacity K of the heat insulating container 20 is determined using the reference substance 22 and the standard sample 23, and then the same measurement is performed using the reference substance 22 and the sample 25 to be measured. Calculate the specific heat _c1X of 25.

When the heat capacity K of the heat insulating container 20 is known in advance, the operation of measuring the heat capacity K is unnecessary. In addition, this first
In the embodiment, the shape and size of the reference substance 22, the standard sample 23, and the measured sample 25 are all the same.

When obtaining the heat capacity K of the heat insulating container 20, first, only the standard sample 23 is placed inside the heat insulating container 20. Next, a sample measurement probe 24 is attached to the standard sample 23 inside the heat insulating container 20.
The thermal contact 24a of the
While recording with 0, wait for the standard sample 23 to stabilize thermally. In other words, it waits until the standard sample 23 reaches thermal equilibrium inside the heat insulating container 20 and its temperature becomes constant over time. Then, when the thermal equilibrium is reached, the temperature value of the standard sample 23 is set as the initial temperature t ₀₂ (° C.) of the standard sample 23.

Then, the changeover switch 31 is operated to connect the reference measurement probe 21 to the power supply 32, and the appropriate voltage of the resistance wire 21a is applied from the power supply 32 to heat the reference substance 22 to a predetermined temperature outside the heat insulating container 20. . After confirming that the temperature of the reference material 22 has become uniform over the entirety, the reference material 22 is housed inside the heat insulating container 20.

Then, the changeover switch 31 is operated to switch and connect the reference measurement probe 21 to the temperature measurement device 30, and the reference substance is detected by the temperature measurement device 30.
After the temperature of 22 can be measured and recorded, the reference substance 22 is brought into contact with a standard sample 23 as shown in FIG. The temperature value of the reference material 22 at the start of contact is
The initial temperature of the reference substance 22 is t ₀₁ (° C.).

Then, while the temperature change in the contact state between the reference substance 22 and the standard sample 23 is measured and recorded by the temperature measuring device 30, the reference substance 22 and the standard sample 23 reach thermal equilibrium. From the temperature data recorded by the temperature measuring device 30, the reference substance
The temperature θ ₀ (° C.) when the thermal equilibrium between the reference sample 22 and the reference sample 23 is reached is read.

According to the law of thermodynamics, the reference substance 22
A relational expression of m ₀₁ c ₀₁ (t ₀₁ −θ ₀ ) = (m ₀₂ c ₀₂ + K) (θ ₀ −t ₀₂ ) is established between the reference sample 23 and the standard sample 23. Specific heat c ₀₁ and mass m of reference substance 22
The specific heat c ₀₂ and the mass m _{02 of 01} and the standard sample 23 are known,
Since the initial temperature t ₀₁ of the reference substance 22, the initial temperature t ₀₂ of the standard sample 23, and the heat average temperature θ ₀ are known from the temperature data recorded by the temperature measuring device 30, the heat capacity K of the heat insulating container 20 is given by the following equation. Can be calculated from

Next, a method for measuring the specific heat c _{1X of the} sample 25 to be measured will be described. As described above, the measurement sample 25 is the desired substance, such as a ceramic material, its mass m ₁₂ is known.

First, the reference substance 22 placed inside the heat insulating container 20
Then, the standard sample 23 is taken out together with the reference measurement probe 21 and the sample measurement probe 24. Thereafter, only the sample 25 to be measured is placed inside the heat insulating container 20.

Next, the sample 25 to be measured is
The thermal contact 24a of the sample measurement probe 24 is brought into contact with the
Wait for it to settle thermally. In other words, it waits for the sample 25 to be measured to reach the thermal equilibrium inside the heat insulating container 20 and for the temperature to become constant over time. Then, the temperature value of the sample 25 to be measured when the thermal equilibrium is reached is calculated as the initial temperature of the sample 25 to be measured.
t ₁₂ (° C).

Next, in the same manner as in the case where the heat capacity K of the heat insulating container 20 is obtained, the changeover switch 31 is operated to switch and connect the reference measurement probe 21 to the power source 32. Apply an appropriate voltage to the reference substance 22
Is heated to a predetermined temperature. After confirming that the temperature of the reference material 22 has become uniform over the entirety,
Is housed inside the heat insulating container 20. This reference substance 22 is the same as that used for obtaining the heat capacity K of the heat insulating container 20.

Then, the changeover switch 31 is operated to switch and connect the reference measurement probe 21 to the temperature measurement device 30, and the reference substance is detected by the temperature measurement device 30.
After the temperature of 22 can be measured and recorded, the reference substance 22 is brought into contact with the sample 25 to be measured, as shown in FIG. The temperature value of the reference substance 22 at the start of the contact is defined as the initial temperature t ₁₁ (° C.) of the reference substance 22.

Then, while measuring and recording the temperature change in the contact state between the reference substance 22 and the sample 25 to be measured by the temperature measuring device 30, it waits until the sample 25 of the reference substance 22 reaches thermal equilibrium. From the temperature data recorded by the temperature measuring device 30, the temperature θ when the reference substance 22 and the sample 25 reach thermal equilibrium.
₁ Read (° C).

According to the law of thermodynamics, the reference substance 22
A relational expression of m ₀₁ c ₀₁ (t ₁₁ −θ ₁ ) = (m ₁₂ c _1X + K) (θ ₁ −t ₁₂ ) is established between the sample and the sample 25 to be measured. Specific heat c ₀₁ and mass m of reference substance 22
₀₁ and the mass m _{12 of the} sample 25 to be measured are known, and the temperature
From the temperature data recorded at 0, the initial temperature of reference material 22
t ₁₁ , initial temperature t _{12 of the} sample 25 to be measured and thermal equilibrium temperature θ ₁
Since it is known, the specific heat c ₀₁ of DUT 25 can be calculated from the following equation.

Second Embodiment FIGS. 2A and 2B are cross-sectional views showing a second embodiment of the specific heat measuring device of the present invention.

The specific heat measuring apparatus of the second embodiment is different from the first embodiment in that
Two reference substances are used. The two reference substances may be different materials or the same material.

The specific heat measuring apparatus 10 of the second embodiment includes an insulating container 20 formed of an appropriate insulating material, and a reference measuring probe 21 used for measuring the temperature of the reference substance 22 inside the insulating container 20.
And the ratio measurement sample 25 or the standard sample 23 inside the insulation container 20
A sample measurement probe 24 used to measure the temperature of the sample, a reference measurement probe 26 used to measure the temperature of another reference material 27 inside the insulated container 20, and reference measurement probes 21 and 24.
And a sample measuring probe 24 each having a temperature measuring device 30 electrically connected thereto.

The reference measurement probe 21 is configured to be selectively connected to the temperature measuring device 30 or the heating power supply 32 by the changeover switch 31. When measuring the temperature of the solid reference material 22, the reference measurement probe 21 is connected to a temperature measuring device 30, and when heating the solid reference material 22, it is connected to a heating power supply 32.

As shown clearly in FIG. 3, the reference measurement probe 21 includes a resistance wire (for example, platinum wire) 21 brought into contact with the reference material 22.
a, and two conductive wires 21b and 21c each having one end connected to both ends of the resistance wire 21a. The other ends of the conductors 21b and 21c are connected to corresponding terminals of the changeover switch 31, respectively. At the time of temperature measurement, heat data detected by the resistance wire 21a is transmitted to the temperature measuring device 31 via the conductors 21b and 21c and the changeover switch 31, and the temperature value of the reference substance 22 is calculated based on the data. During heating, the changeover switch 31 and the conductors 21b, 2b
Appropriate voltage is applied from the power supply 32 to the resistance wire 21a via 1c, whereby the reference substance 22 is heated.

Similarly, the reference measurement probe 26 is configured to be selectively connected to the temperature measuring device 30 or the heating power supply 32A by the changeover switch 31A. When measuring the temperature of the solid reference material 27, the reference measurement probe 26 is connected to the temperature measuring device 30, and when heating the solid reference material 27, it is connected to the heating power supply 32A.

As shown clearly in FIG. 3, the reference measurement probe 26 includes a resistance wire (for example, platinum wire) 26 brought into contact with a reference material 27.
a, and two conductive wires 26b and 26c each having one end connected to both ends of the resistance wire 26a. The other ends of the conductors 26b and 26c are connected to corresponding terminals of the changeover switch 31A, respectively. At the time of temperature measurement, heat data detected by the resistance wire 26a is transmitted to the temperature measuring device 30 via the conducting wires 26b and 26c and the changeover switch 31A, and the temperature value of the reference substance 27 is calculated based on the data. During heating, switch 31A and lead 2
Appropriate voltage is applied from the power source 32 to the resistance wire 26a via 6b and 26c, thereby heating the reference material 27.

The sample measurement probe 24 has the same configuration as that of the first embodiment. That is, the thermal junction 24a and the two thermocouple wires 24b and 24c
And constitute a thermocouple. Hot junction 24a
Is brought into contact with the measured sample 25 or the standard sample 23 at the time of measurement. One end of each of the thermocouple wires 24b and 24c is connected to the thermal contact 24a, and the other end is connected to a corresponding terminal of the temperature measuring device 30, respectively. The heat data detected at the hot junction 24a is transmitted to the temperature measuring device 30 through the thermocouple wires 24b and 24c, and the temperature value of the sample 25 or the standard sample 23 is calculated based on the data.

The sample to be measured 25, the standard sample 23, and the reference substance 22 are the first
This is the same as the embodiment. In the second embodiment, the reference material 27 is made of the same material as the reference material 22, and has the same specific heat _c01 and the same mass _m01 'as the reference material 22. This is for the convenience of operation, and it goes without saying that the reference material 22 may be formed of a different material.

Next, using the specific heat measurement device 10 having the above configuration,
A method for measuring the specific heat c _{1X of the} sample 25 to be measured will be described. In this method, first, the reference substance 22 and the standard sample
The heat capacity K of the heat insulating container 20 is obtained by using 23, and then the same measurement is performed by using the reference substance 22 and the sample 25 to be measured to calculate the specific heat c _{1X of the} sample 25 to be measured.

When the heat capacity K of the heat insulating container 20 is known in advance, the action of measuring the heat capacity K is unnecessary. Also, this second
In the embodiment, the shapes and sizes of the reference materials 22 and 27, the standard sample 23, and the sample 25 to be measured are all the same.

When obtaining the heat capacity K of the heat insulating container 20, first, only the standard sample 23 is placed inside the heat insulating container 20. Next, a sample measurement probe 24 is attached to the standard sample 23 inside the heat insulating container 20.
The thermal contact 24a of the
While recording with 0, wait for the standard sample 23 to stabilize thermally. In other words, it waits until the standard sample 23 reaches thermal equilibrium inside the heat insulating container 20 and its temperature becomes constant over time. Then, the temperature value of the standard sample 23 when the thermal equilibrium is reached is defined as the initial temperature t ₀₂ (° C.) of the standard sample 23.

Next, the changeover switch 31 is operated to connect the reference measurement probe 21 to the power supply 32, and the voltage is appropriately applied to the resistance wire 21 a from the power supply 32 to heat the reference substance 22 to a predetermined temperature outside the heat insulating container 20. . At this time, switch 31 is turned on
By intermittently switching between the power supply 32 and the power supply 32, the temperature change of the reference material 22 can be easily known, which is convenient.

At the same time, the reference measurement detection 26 is connected to the power supply 32A by operating the changeover switch 31A, and an appropriate voltage is applied to the resistance wire 26a from the power supply 32A from the power supply 32A to change the reference substance 27 to the reference substance 22 outside the heat insulating container 20. Heat to the same temperature. Reference substance
At this time, switch 31A is turned on as shown in
By intermittently switching between 0 and the power supply 32A, the temperature change of the reference material 27 can be easily known, which is convenient.

In the second embodiment, the reference materials 22 and 27 are heated to the same temperature. However, this is for the convenience of the operation of Go, and therefore, the reference materials 22 and 27 are heated to different temperatures. Of course, it may be possible.

After confirming that the temperatures of reference materials 22 and 27 were uniform throughout them, both reference materials 22 and 27
Housed inside the heat insulating container 20.

After that, by operating the changeover switches 31 and 31A, the reference measurement probes 21 and 26 are switched and connected to the temperature measuring device 30, so that the temperature measuring device 30 can measure and record the temperature of both the reference materials 22 and 27, As shown in FIG. 2A, the reference materials 22 and 27 are brought into contact with the standard sample 23 from both sides thereof. The temperature value of the reference materials 22 and 27 at the start of the contact is defined as the initial temperature t ₀₁ (° C.) of the reference materials 22 and 27.

Then, while the temperature change in the contact state between the reference materials 22 and 27 and the standard sample 23 is measured and recorded by the temperature measuring device 30, it waits until the reference materials 22 and 27 and the standard sample 23 reach thermal equilibrium. From the temperature data recorded by the temperature measuring device 30, the temperature θ ₀ (° C.) when the reference substances 22 and 27 and the standard sample 23 reach thermal equilibrium is read.

According to the law of thermodynamics, the reference substance 22
And 27 and the standard sample 23, a relational expression of 2m ₀₁ c ₀₁ (t ₀₁ −θ ₀ ) = (m ₀₂ c ₀₂ + K) (θ ₀ −t ₀₂ ) is established. The specific heat c ₀₁ and the mass m ₀₁ of the reference materials 22 and 27 and the specific heat c ₀₂ and the mass m _{02 of the} standard sample 23 are known, and from the temperature data recorded by the thermometer 30, the initial temperature t of the reference materials 22 and 27 is obtained. ₀₁ , the initial temperature t ₀₂ of the standard sample 23 and the thermal equilibrium temperature θ ₀ are known, so that the heat capacity K of the heat insulating container 20 can be calculated from the following equation.

Next, a method for measuring the specific heat c _{1X of the} sample 25 to be measured will be described.

First, the reference substance 22 placed inside the heat insulating container 20
27 and the standard sample 23 are taken out together with the reference measurement probes 21 and 26 and the sample measurement probe 24. Then, the measured sample 25
Only the inside is placed inside the heat insulating container 20.

Next, the sample 25 to be measured is
The thermal contact 24a of the sample measuring probe 24 is brought into contact with the
Wait for 25 to stabilize thermally. In other words, the insulation container 20
Wait until the sample 25 reaches thermal equilibrium and its temperature becomes constant over time. Then, the temperature value of the sample 25 when the thermal equilibrium is reached is defined as the initial temperature t ₁₂ (° C.) of the sample 25.

Next, in the same manner as in the case where the heat capacity K of the heat insulating container 20 is obtained, the changeover switch 31 is operated to switch and connect the reference measurement probe 21 to the power source 32. Apply an appropriate voltage to the reference substance 22
Is heated to a predetermined temperature. At the same time, the changeover switch 31A is operated to switch and connect the reference measurement probe 26 to the power supply 32A, and outside the heat insulating container 20, an appropriate voltage is applied from the power supply 32A to the resistance wire 26a to change the reference substance 27 to the reference substance 22. Heat to the same temperature as.

After confirming that the temperatures of the reference materials 22 and 27 have become uniform throughout them, the reference materials 22 and 27 are housed inside the insulated container 20. These reference materials 22 and 27 are the same as those used for determining the heat capacity K of the heat insulating container 20.

After that, by operating the changeover switches 31 and 31A, the reference measurement probes 21 and 26 are switched and connected to the temperature measuring device 30, so that the temperature of the reference materials 22 and 27 can be measured and recorded by the temperature measuring device 30, As shown in FIG. 2B, the reference materials 22 and 27 are brought into contact with the sample 25 to be measured from both sides thereof. The temperature values of reference materials 22 and 27 at the start of contact are
The initial temperature of the reference substance 22 is t ₁₁ (° C.).

Then, while the temperature change in the contact state between the reference materials 22 and 27 and the sample 25 is measured and recorded by the temperature measuring device 30, it waits until the reference materials 22 and 27 and the sample 25 reach thermal equilibrium. From the temperature data recorded by the temperature measuring device 30, the temperature θ ₁ (° C.) when the reference substances 22 and 27 and the sample 25 reach thermal equilibrium is read.

According to the law of thermodynamics, the reference substance 22
A relational expression of 2m ₀₁ c ₀₁ (t ₁₁ −θ ₁ ) = (m ₁₂ c _1X + K) (θ ₁ −t ₁₂ ) is established between the sample and the sample 25 to be measured. Reference material 22 and 27 the specific heat c ₀₁ and the mass m ₀₁ of the mass m ₁₂ of the measured sample 25 is known, the temperature data recorded by a temperature measuring device 30, the reference material 22 and 27 the initial temperature t ₁₁ of the Since the initial temperature t ₁₂ and the thermal equilibrium temperature θ ₁ of the measurement sample 25 are known, the specific heat of the measurement sample 25 is
c ₀₁ can be calculated from the following equation.

(Example) Next, in order to confirm the operation and effect of the present invention, the above-described specific heat measuring apparatus of the first example was actually manufactured, and an experiment was performed as follows. The results are shown in FIG. 5 and FIG. FIG. 5 is a graph showing the change over time of the thermoelectromotive force of the reference measurement probe 21 when measuring the heat capacity of the heat insulating container 20.
FIG. 6 is a graph showing the change over time of the thermoelectromotive force of the sample measurement probe 24 when measuring the specific heat of the sample 25 to be measured.

As the reference substance 22, the specific heat c ₀₁ is 0.392 (J / g · K)
And copper having a mass m ₀₁ of 19.85 g was used. Standard sample 23
The specific heat _c02 is 0.92 (J / gK) and the mass _m02 is 75.
00 g of quartz glass was used.

First, when the standard sample 23 is placed inside the heat insulating container 20 and the initial temperature t ₀₂ when thermally stabilized is measured, as shown in FIG. Resistance values:
106.35Ω). On the other hand, the reference material 22 was heated outside the heat insulating container 20 so that the temperature became uniform as a whole. After that, the sample is stored inside the heat insulating container 20 and the standard sample 23
Was contacted. Initial temperature of reference material 22 at the start of contact
₀₁ is 110 ° C (resistance value of the resistance wire 21a of the reference measurement probe 21: 14
3.01Ω) (see FIG. 5).

Subsequently, when the temperature θ ₀ when the reference material 22 and the standard sample 23 brought into contact with each other reach thermal equilibrium inside the heat insulating container 20 is measured, the temperature θ 25 ° C. (the resistance wire of the reference measurement probe 21) is measured.
The resistance value of 21a was 109.90Ω) (see FIG. 5).

Therefore, the heat capacity K of the heat insulating container 20 is It was calculated.

Then, the reference material 22 and the standard sample 23 is taken out from the heat insulating container 20, the mass m ₁₂ placed the measured sample 25 of 64.90g inside the insulated container 20. When measuring an initial temperature t ₁₂ when thermally stable, as shown in FIG. 6, 16.
06 ° C (resistance value of resistance wire 21a of reference measurement probe 21: 106.37Ω)
Met. On the other hand, the reference material 22 was heated outside the heat insulating container 20 so that the temperature became uniform as a whole. Thereafter, it was housed inside the heat insulating container 20 and brought into contact with the sample 25 to be measured. The initial temperature t ₁₁ of the reference substance 22 at the start of contact is 109.81
° C (resistance value of resistance wire 21a of reference measurement probe 21: 142.94Ω).

Subsequently, when the temperature θ ₁ when the reference substance 22 and the sample 25 contact each other reaches thermal equilibrium inside the heat insulating container 20 is measured, the resistance θ is 24.99 ° C. (the resistance of the resistance wire 21a of the reference measurement probe 21). Value: 109.85Ω) (see FIG. 6).

Therefore, the specific heat c _{1X of the} sample 25 to be measured is It was calculated.

(Modification) In both the above embodiments, as shown in FIG. 3, the resistance lines 21a and 26a of the reference measurement probes 21 and 26 are connected to the reference material 22.
And 27 are respectively in contact with one main surface. However, the present invention is not limited to this, and various modifications are possible.

For example, as shown in FIG. 4 (a), the reference substances 22 and 27 are respectively divided into two reference substance halves 22A and 22B and 27A.
Halves 22A and 22B.
The resistance wires 21a and 26a of the reference measurement probes 21 and 26 may be interposed between B and 27A and 27B so as to be in contact with each other.

Further, as shown in FIG. 4 (b), holes 22C and 27C are formed in the reference materials 22 and 27 in the diameter direction, respectively, and the reference measurement probes 21 and b26 are formed in the holes 22C and 27C.
May be inserted, respectively.

[Effects of the Invention] As is clear from the above description, according to the specific heat measuring apparatus of the present invention, the thermal equilibrium of the sample can be achieved without performing the conventional stirring operation, and the influence by the contact with water can be achieved. Measurement can also be performed on a sample to be received (for example, ceramic before firing). It is also possible to heat a substance to a temperature exceeding 100 ° C. Further, the labor required for the specific heat measurement operation can be reduced, and the occurrence of a measurement error can be suppressed.

[Brief description of the drawings]

1 (a) and 1 (b) are cross-sectional views showing a first embodiment of the specific heat measuring device of the present invention. 2 (a) and 2 (b) are sectional views showing a second embodiment of the specific heat measuring apparatus of the present invention. FIG. 3 shows FIGS. 1 (a), (b) and 2 (a),
It is a perspective view which shows the structure of the reference | standard substance and the reference | standard measurement probe used for the Example shown to (b). FIGS. 4 (a) and 4 (b) show modified examples of the reference material and the reference measurement probe used in the embodiment shown in FIGS. 1 (a) and 1 (b) and FIGS. 2 (a) and 2 (b). FIG. FIG. 5 is a graph showing the change over time of the thermoelectromotive force of the reference measurement probe when measuring the heat capacity of the heat insulating container. FIG. 6 is a graph showing the change over time of the thermoelectromotive force of the sample measurement probe when measuring the specific heat of the sample to be measured. 10 Specific heat measuring device 20 Insulated container 21, 26 Reference measuring probe 21a, 26a Resistance wire 21b, 26b Conductor 21c, 26c Conductor 22 Reference material 22A, 22B Reference material Half 23 …… Standard sample 24 …… Sample measuring probe 24a …… Resistance wire 24a …… Wire 24c …… Wire 25 …… Sample under measurement 27 …… Reference materials 27A and 27B …… Reference material half 30… Temperature measuring device 31, 31A …… Changeover switch 32, 32A …… Power supply for heating

Claims (5)

(57) [Claims] 1. A specific heat measuring device for measuring a specific heat c _1X of a solid sample having a known mass m ₁₂ , wherein: (a) an insulating container having a heat capacity of K; and (b) the sample in the insulating container. (C) a specific heat c ₀₁ and a mass m ₀₁ in the heat insulating container.
And (d) measuring the temperature of the sample via the first measurement probe and measuring the temperature of the reference material via the third measurement probe. (E) a changeover switch for selectively connecting the second measuring probe to the temperature measuring means or a power supply for heating; and the sample disposed inside the cross-sectional container. its power but the temperature t ₁₂ when thermally stable measured using the first measuring Saguko and said temperature measuring means, on the other hand, by connecting the second measuring Saguko by the selector switch to the heating power source After the reference material is heated outside the heat-insulating container, the reference material is accommodated inside the heat-insulating container and brought into contact with the sample, and the second switch connected to the temperature measuring means by the changeover switch 2 Using the measuring probe and its temperature measuring means, the temperature t of the reference material at the start of contact
₁₁ was measured, and the temperature θ ₁ when the reference material and the sample in contact with each other reached thermal equilibrium was measured using the first measuring probe, the second measuring probe, and the temperature measuring means. Using the measured values of t ₁₂ , t ₁₁ and θ ₁ thus obtained, the following relational expression A specific heat measuring apparatus for calculating the specific heat c _1X of the sample. 2. The method according to claim 1, wherein the second measuring probe includes a resistor that contacts the reference material, and a conductor that connects the resistor to the temperature measuring means. The first measuring probe is connected to the sample. 2. The specific heat measuring apparatus according to claim 1, further comprising: a hot contact that is in contact with the thermojunction; and a thermocouple wire that connects the hot contact to the temperature measuring means. 3. The specific heat according to claim 2, wherein the reference material is composed of two halves, and the resistor of the second measurement probe is in contact with and sandwiched between the halves. measuring device. 4. The specific heat measuring apparatus according to claim 2, wherein the resistor of the second measuring probe is embedded in the reference material. 5. The specific heat measuring apparatus according to claim 1, wherein a plurality of said second measuring probes are provided.