JP3953170B2 - Specific heat measurement method and differential scanning calorimeter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a specific heat measurement method and a differential scanning calorimeter that can measure the specific heat of a sample with high accuracy.
[0002]
[Prior art]
It is required from both the engineering application of materials and the theory of physical properties to accurately determine the specific heat value of the material as a function of temperature. Conventionally, a twin-type differential scanning calorimeter (heat flux type) shown in FIG. 3 has been proposed as a means for obtaining the specific heat of this substance.
[0003]
As shown in FIG. 3, this differential scanning calorimeter has a heat flow in a soaking vessel a that is heated by an electric furnace (not shown) arranged on the outer periphery so that both ends are in thermal contact with the soaking vessel a. A metal thin plate b which is a measuring plate is provided, and a sample cell c ₁ and an empty cell c ₂ are respectively disposed at thermally symmetric positions (No. 1 and No. 2) of the metal thin plate b. The sample temperature thermocouple d ₁ and the empty cell thermocouple d ₂ are attached to the positions corresponding to the sample cell c ₁ and the empty cell c ₂ , respectively. It is obtained by the following method.
[0004]
This measurement is performed twice. In the first measurement, the calorimeter No. No. 1 sample, no. An empty cell c ₂ is arranged at position ₂ . Next, in the second measurement, the calorimeter No. No. 1 standard sample with known heat capacity, No. 1 An empty cell c ₂ is arranged at position ₂ .
[0005]
(1) First measurement.
[0006]
The heat flux (Φ) from the soaking vessel a (heat source) of the thin metal plate b is expressed as follows: heat source temperature [T _h (T _h1 , T _h2 )] and sample temperature measurement point temperature [T _m (T _m1 , T _m2 ) ] Is equal to the difference in temperature divided by the thermal resistance (R).
[0007]
Φ = (T _h −T _m ) / R (1)
Due to this heat flux, the sample temperature measurement point portion (around the position where the sample cell is placed) with a heat capacity of C _m (C _m1 , C _m2 ), an empty cell with a heat capacity of C (C ₁ , C ₂ ), and a heat capacity of C The sample of _s rises in temperature, and the rate of temperature rise is dT / dt = φ. No. For one cell c ₁ ,
(T _h1 −T _m1 ) / R ₁ = φ ₁ (C _m1 + C ₁ + C _s ) (2)
No. Similarly, for cell 2 of cell ₂
(T _h2 −T _m2 ) / R ₂ = φ ₂ (C _m2 + C ₂ ) (3)
Under ideal conditions,
T _h1 = T _h2 R ₁ = R ₂ = R ₍₁₎ φ ₁ = φ ₂ = φ ₍₁₎
C _m1 = C _m2 = C _m C ₁ = C ₂ (4)
Under these conditions, from equations (2) and (3):
(T _m2 -T _m1 ) / R ₍₁₎ = φ ₍₁₎ · C _s (5)
ΔT ₍₁₎ = T _m2 -T _m1 = R ₍₁₎ · φ ₍₁₎ · C _s (5 ')
Here, the subscript (1) indicates the first measurement.
[0008]
(2) Second measurement.
[0009]
No. No. 1 cell c ₁ is charged with a standard sample with a known heat capacity. The second cell is empty. Similar to the above, under ideal conditions, the equations (6), (7), and (8) hold as in the equations (2), (3), and (5). _Let C _r be the heat capacity of the standard sample.
[0010]
(T _h1 −T _m1 ) / R ₁ = φ ₁ (C _m1 + C ₁ + C _r ) (6)
(T _h2 −T _m2 ) / R ₂ = φ ₂ (C _m2 + C ₂ ) (7)
(T _m2 −T _m1 ) / R ₍₂₎ = φ ₍₂₎ · C _r (8)
ΔT ₍₂₎ = T _m2 -T _m1 = R ₍₂₎ · φ ₍₂₎ · C _r (8 ')
Here, the subscript (2) indicates the second measurement.
[0011]
(3) The heat capacity of the sample is obtained from the above two measurement results.
[0012]
From (5 ') and (8'),
ΔT ₍₁₎ / ΔT ₍₂₎ · R ₍₂₎ / R ₍₁₎ = φ ₍₁₎ / φ ₍₂₎ · C _s / C _r (9)
The following ideal conditions are assumed in two measurements.
[0013]
R ₍₂₎ = R ₍₁₎ φ ₍₁₎ = φ ₍₂₎ (10)
Therefore, equation (9) is
ΔT ₍₁₎ / ΔT ₍₂₎ = C _s / C _r (11)
C _s = C _r · ΔT ₍₁₎ / ΔT ₍₂₎ (12)
Since ΔT ₍₁₎ and ΔT ₍₂₎ are both numerical values that can be measured, the heat capacity C _s of the sample can be obtained from equation (12).
[0014]
The ideal condition of R ₁ = R _{2 in} the equation (4) may not be satisfied. In this case, the third measurement is performed. The third measurement was No. 1, no. Both two cells are performed as empty cells. In this measurement, No. 1 and No. Assuming that the temperature difference of 2 is ΔT ₍₃₎ , C _s can be obtained by the following equation even when R ₁ = R ₂ is not satisfied.
[0015]
C _s = C _r · (ΔT ₍₁₎ −ΔT ₍₃₎ ) / (ΔT ₍₂₎ −ΔT ₍₃₎ ) (12 ′)
The third measurement can be omitted when the measurement conditions are the same. However, in order to determine the specific heat of the sample, at least two measurements must be made.
[0016]
[Problems to be solved by the invention]
In the specific heat measurement by the above-described conventional twin type differential scanning calorimeter, T _h1 = T _{h2 in the} equation (4) shown as an ideal condition. 1 and No. This means that the temperature distribution at position 2 is uniform. However, in practice, a slight temperature difference occurs between the two, and it must be considered that the equations (5) and (8) are accompanied by an error.
[0017]
In particular, when the sample temperature becomes high, this tendency increases with fluctuations in temperature control.
[0018]
Furthermore, equation (10) also actually involves an error. Equation (10), which takes two measurements of the sample and the standard sample as exactly the same conditions, is an ideal assumption, and is actually not equal and causes an error.
[0019]
When the specific heat is actually measured using the calorimeter, a variation of ± 5% occurs near room temperature, and a variation of ± 8% occurs at 500 ° C. or higher. In particular, a variation of ± 10% or more occurs at 1000 ° C. or higher.
[0020]
Therefore, in order to measure precise specific heat using a differential scanning calorimeter in a wide range from room temperature to high temperature,
a. Countermeasure for existence of temperature distribution in the surface of calorimeter.
[0021]
b. A method that enables measurement of a sample and a standard sample by one measurement instead of two measurements.
[0022]
These two problems must be solved.
[0023]
Conventionally, a method for solving the problem b has been proposed.
[0024]
It is Wanderlich's triple-cell differential scanning calorimeter [B. Wunderlich, J.M. Thermal Anal. 32, P.1949-1955 (1987)].
[0025]
FIG. 4 shows the principle of the differential scanning calorimeter.
[0026]
Place the reference sample, the standard sample, and the sample at three equal positions on the heat flux meter on the same plane, and the temperature difference between the reference sample and the sample and the temperature difference between the reference sample and the standard sample, respectively. If measured at the same time, only one measurement is required.
[0027]
A measurement method using this calorimeter will be described.
[0028]
No. 1 cell c ₁ is an empty cell (reference sample). In cell c ₂ of No. ₂ , the sample is No. A standard sample is placed in cell 3 of ₃ and heated at a constant rate. For each cell, a formula similar to the formula (2) is established.
[0029]
(T _h1 −T _m1 ) / R ₁ = φ ₁ (C _m1 + C) (13)
(T _h2 −T _m2 ) / R ₂ = φ ₂ (C _m2 + C + C _s ) (14)
(T _h3 −T _m3 ) / R ₃ = φ ₃ (C _m3 + C + C _r ) (15)
Here, T _h1 = T _h2 = T _h3 = T _h R ₁ = R ₂ = R ₃ = R
φ ₁ = φ ₂ = φ ₃ = φ
C _m1 = C _m2 = C _m3 = C _m
Assuming the ideal condition, T _m2 −T _m1 = R · φ · C _s = ΔT ₂₁ (16) according to the equations (14)-(13) and (15)-(13)
T _m3 −T _m1 = R · φ · C _r = ΔT ₃₁ (17)
(16) ΔT ₂₁ / ΔT ₃₁ = C _s / C _r (18)
Therefore,
C _s = C _r · ΔT ₂₁ / ΔT ₃₁ (19)
No. 2 and No. No. 1 temperature difference and No. 1 3 and no. If the temperature difference of 1 is measured, the heat capacity of the sample can be obtained.
[0030]
With this triple cell method, the heat capacity of the sample could be obtained by only one measurement. This problem is still unresolved. The assumption of T _h1 = T _h2 = T _h3 does not hold when there is a non-uniform temperature around the sample. This phenomenon becomes remarkable especially in a high temperature range of 500 ° C. or more, and the variation in measurement becomes large, and precise specific heat measurement within an error range of ± 3% is impossible.
[0031]
Thus, the conventional technique cannot measure the specific heat of the sample with high accuracy at temperatures higher than 500 ° C. to 600 ° C.
[0032]
The present invention provides a specific heat measurement method and a differential scanning calorimeter that can measure the specific heat in a high temperature range with high accuracy even when the temperature around the sample is non-uniform in view of the above-described conventional problems. This is the issue.
[0033]
[Means for Solving the Problems]
In order to solve the above problems, a differential scanning heat flow meter of the present invention is a heat flux type differential scanning heat flow meter, in which a first cell and a second cell are placed in a soaking vessel capable of raising and lowering temperature. A first heat flow meter board having a temperature sensor attached to each of the first cell and the second cell so as to allow temperature measurement, a third cell serving as a reference sample, and a fourth cell serving as a reference sample. And a second heat flow meter plate having a temperature sensor attached to each of the third cell and the fourth cell so that the temperature can be measured, and both ends of the first heat flow meter plate, The two end portions of the heat flow meter plate are mounted in thermal contact with each other at the same position in the soaking vessel. The first cell is a cell containing a sample, an empty cell, and a standard. One of the cells containing the sample, and the second cell is either the empty cell or the cell containing the standard sample. , The third cell and the fourth cell is an empty cell, the sample, based on the temperature difference between the standard sample and the reference sample has a configuration for obtaining the specific heat of the sample.
In addition to the above configuration, the invention according to claim 2 has a configuration in which the first heat flow meter plate and the second heat flow meter plate are provided in the soaking vessel at a symmetrical structure and position. .
According to a third aspect of the present invention, in the first heat flow meter plate and the second heat flow meter plate, a hole is provided around the first cell, the second cell, the third cell, and the fourth cell. It has the structure which is made.
The specific heat measurement method according to the invention of claim 4 is a heat flux type differential scanning heat flow meter, wherein a first cell, a second cell, and a first cell are placed in a soaking vessel capable of raising and lowering temperature. And a first heat flow meter board having a temperature sensor attached to each of the second cells so that the temperature can be measured, a third cell serving as a reference sample, a fourth cell serving as a reference sample, and a third cell A second heat flow meter plate having a temperature sensor attached to each of the first cell and the fourth cell so that the temperature can be measured, and both ends of the first heat flow meter plate, and a second heat flow meter plate The differential scanning heat flow meter is mounted in such a manner that both ends thereof are in thermal contact with each other at the same position in the soaking vessel, and the first cell, the second cell, the third cell, and the second cell When the thermal resistances between the four cells and the soaking vessel were all equal, the temperature of the first cell containing the sample and the standard sample were added. And the temperature of the second cell, by simultaneously measuring once the temperature and the third cell and a fourth cell of the sky, and has a configuration that determines the specific heat of the sample.
The invention according to claim 5 is the differential scanning heat flow meter in addition to the above configuration, and when the thermal resistance is not equal, all of the first cell, the second cell, the third cell, and the fourth cell are A first step of simultaneously measuring the temperature of each cell when empty, the temperature of the first cell containing the sample, the temperature of the second cell containing the standard sample, the third cell and the empty A second step of simultaneously measuring each temperature of the four cells, each temperature of the first cell and the second cell containing the standard sample, each temperature of the empty third cell and the fourth cell, And a specific heat of the sample based on the temperature difference between the first cell and the third cell and the temperature difference between the second cell and the fourth cell in each step. Is determined.
According to the sixth aspect of the present invention, the temperature difference between the first cell and the third cell and the temperature difference between the third cell and the fourth cell are already obtained by the first process and the third process. The specific heat of the sample is determined by only one measurement in the second process.
[0034]
The specific heat measurement method using the heat flux type differential scanning calorimeter will be described with reference to FIG. For one cell, a formula similar to the above formula (2) is obtained.
[0035]
(T _h1 −T _m1 ) / R ₁ = φ ₁ (C _m1 + C ₁ + C _s ) (20)
Reference numerals have the meanings corresponding to those described in the section of the prior art.
[0036]
No. Similarly for cell 3
(T _h3 −T _m3 ) / R ₃ = φ ₃ (C _m3 + C ₃ ) (21)
Now, even if there is a non-uniform temperature in the surface of the calorimeter, T _h1 and T _h3 are in the same position and are in thermal contact, so it can be considered that T _h1 = T _h3 .
[0037]
Similar to the above equation (4), the following ideal condition is assumed.
[0038]
R ₁ = R ₃ = R ₁₃ φ ₁ = φ ₃ = φ ₁₃ C _m1 = C _m3 = C _m13
C ₁ = C ₃ = C ₁₃ (22)
From (20), (21), and (22), (T _m3 −T _m1 ) / R ₁₃ = φ ₁₃ · C _s (23)
No. 2 and No. Similarly for the four cells, R ₂ = R ₄ = R ₂₄ φ ₂ = φ ₄ = φ ₂₄ C _m2 = C _m4 = C _m24
C ₂ = C ₄ = C ₂₄
Assuming that (T _m4 −T _m2 ) / R ₂₄ = φ ₂₄ · C _r (24)
As an ideal condition,
R ₁₃ = R ₂₄ φ ₁₃ = φ ₂₄ (25)
Then,
(23) (24) From the equation (25), (T _m3 -T _m1 ) / (T _m4 -T _m2 ) = C _s / C _r (26)
Or
Cs = Cr · (T _m3 −T _m1 ) / (T _m4 −T _m2 ) (27)
Since (T _m3 -T _m1 ) / (T _m4 -T _m2 ) is obtained by measurement, the heat capacity of the sample can be determined by only one measurement.
[0039]
Also, with this method, even if there is a non-uniform temperature in the surface of the calorimeter, T _h1 and T _h3 are equal, so that the result can be measured with high accuracy without affecting the result.
[0040]
In the above measurement method, it is assumed that R ₁ , R ₂ , R ₃ , and R ₄ are equal, but the specific heat can be measured even when they are not equal.
[0041]
In this case, three measurements are required.
[0042]
In the first measurement, all cells are measured with empty cells. Four formulas similar to the formula (21) are obtained.
[0043]
(T _h1 −T _m1 ) / R ₁ = φ ₁ (C _m + C) (28)
(T _h3 −T _m3 ) / R ₃ = φ ₃ (C _m + C) (29)
(T _h2 −T _m2 ) / R ₂ = φ ₂ (C _m + C) (30)
(T _h4 −T _m4 ) / R ₄ = φ ₄ (C _m + C) (31)
Here, since T _h1 = T _{h3 Th h2} = T _h4 , from the equations (28) and (29), the equation (28) − (29) equation T _m3 −T _m1 = R ₁ φ ₁ (C _m + C) − R ₃ φ ₃ (C _m + C)
Assume that φ ₁ = φ ₃ = φ.
[0044]
T _m3 −T _m1 = (R ₁ −R ₃ ) φ (C _m + C) =
(R ₁ −R ₃ ) / R ₁ · R ₁ · φ (C _m + C)
From Equation (28), T _m3 −T _m1 = (R ₁ −R ₃ ) / R ₁ · (T _h1 −T _m1 )
T _m3 −T _m1 = (1−R ₃ / R ₁ ) (T _h1 −T _m1 ) = ΔT _{31 (1)} (32)
Here, ΔT _{31 (1)} represents the first temperature difference measurement value of (T _m3 −T _m1 ).
[0045]
(30) From the equation (31), T _m4 −T _m2 = (1−R ₄ / R ₂ ) (T _h2 −T _m2 ) = ΔT _{42 (1)} (33)
In the second measurement, no. No. 1 in the cell, No. A standard sample with a known specific heat in cell No. 2 3 cells and No. 3 cell. When the cell 4 is measured as an empty cell, the equations (34) to (37) are obtained in the same manner as the equations (28) to (31).
[0046]
(T _h1 −T _m1 ) / R ₁ = φ ₁ (C _m + C + C _s ) (34)
(T _h3 −T _m3 ) / R ₃ = φ ₃ (C _m + C) (35)
(T _h2 −T _m2 ) / R ₂ = φ ₂ (C _m + C + C _r ) (36)
(T _h4 −T _m4 ) / R ₄ = φ ₄ (C _m + C) (37)
Here, since T _h1 = T _{h3 Th h2} = T _m4 , T _m3 −T _m1 = (1−R ₃ / R ₁ ) (T _h1 −T _m1 ) + R ₃ φ from the equations (34) and (35). ₁ C _s (38)
Similarly, (36) (37) T _m4 over T _{m @ 2} = [Delta] T ₄₂ from the equation ₍₂₎ = (1 over _{R 4 / R 2) (T} h2 over _{T m2) + R 4 φ 2} C r ... (39)
(32) From equation (38), T _m3 −T _m1 = ΔT _{31 (2)} = ΔT _{31 (1)} + R ₃ φ ₁ C _s (40)
(33) (39) T _m4 over from the equation _{T m2 = ΔT 42 (2)} = ΔT 42 (1) + R 4 φ 2 C r ... (41)
(40) From equation (41), C _s = C _r · (ΔT _{31 (2)} -ΔT _{31 (1)} ) / (ΔT _{42 (2)} -ΔT _{42 (1)} )
R ₄ / R ₃ (42)
R ₄ / R ₃ is No. 1 cell and No. 1 cell. It can be obtained from measurement in which a standard sample is placed in both of the two cells. If the third measured values of ΔT ₃₁ and ΔT ₄₂ are ΔT _{31 (3)} and ΔT _{42 (3)} ,
R ₄ / R ₃ = (ΔT _{42 (3)} -ΔT _{42 (1)} ) / (ΔT _{31 (3)} -ΔT _{31 (1)} ) (42 ')
Therefore,
C _s = C _r · (ΔT _{31 (2)} −ΔT _{31 (1)} ) / (ΔT _{42 (2)} −ΔT _{42 (1)} )
・ (ΔT42 ₍₃₎ −ΔT42 ₍₁₎ ) / (ΔT31 ₍₃₎ −ΔT31 ₍₁₎ ) (42 ″)
become.
[0047]
Also in this case, even if there is a non-uniform temperature in the surface of the calorimeter, T _h1 and T _h3 are equal, so that the result is not affected and the specific heat can be measured with high accuracy.
[0048]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0049]
FIG. 1 shows a schematic diagram of one example of a twin type heat flux type differential scanning calorimeter of the present invention.
[0050]
In the figure, reference numerals 1 and 2 denote first and second thin metal plates, both of which are heat flow meter plates (actually referred to as temperature sensitive plates), and reference numeral 3 denotes No. 1 on the first thin metal plate 1. 1 is a cell in which a sample (specific heat is unknown) placed in position 1, and No. 4 on No. 1 on the first metal thin plate 1 is placed. No. 2 on the second thin metal plate 2 is a cell for storing a standard sample (having a known specific heat) placed at the position No. 2. 3 and no. 4 is an empty cell.
[0051]
An empty cell 5 (No. 3 position) and an empty cell 6 (No. 3) are positioned symmetrically below the cell 3 (No. 1 position) and the cell 4 (No. 2 position) on the first thin metal plate 1. .4) is arranged on the second thin metal plate 2, and both ends of the first and second thin metal plates 1 and 2 are in good thermal and electrical contact with the soaking vessel 7. ing. No. 1 on the first and second thin metal plates 1 and 2. 1, no. 2, no. 3 and no. The positions of 4 are positions where the thermal resistance with the soaking vessel 7 is the same. Reference numeral 8 is a thermocouple for sample temperature, 9 is a thermocouple for standard sample temperature, and 10 and 11 are thermocouples for empty cell temperature, which are attached to the first and second thin metal plates 1 and 2, respectively.
[0052]
In the drawing, an electric furnace provided on the outer periphery of the soaking vessel 7, a sample temperature thermocouple 8, a standard sample temperature thermocouple 9, and a DC amplifier connected to the empty cell temperature thermocouples 10 and 11, etc. Since a microcomputer, a display, and the like for calculating the specific heat of the sample are well known, they are omitted.
[0053]
FIG. 2 shows another example of the metal thin plate of the heat flux meter.
[0054]
In the figure, the thin metal plate 1 (2) is connected to the end of the thin metal plate via a bridge 13 formed by a hole 12 in which a portion on which the cells 3, 4 (5, 6) are placed is opened. Thus, according to this configuration, the thermal resistance R is increased, and the temperature difference can be increased with respect to the same heat flux. In other words, the sensitivity as a heat flow meter board is improved.
[0055]
Using the twin heat flux type differential scanning calorimeter, the specific heat of the sample is measured by the following method.
[0056]
The difference value between the output of the empty cell temperature thermocouple 10 and the output of the sample temperature thermocouple 8 and the difference value between the output of the empty cell temperature thermocouple 11 and the output of the standard sample temperature thermocouple 9 are calculated using a microcomputer. Then, the difference value and the specific heat value of the standard sample are substituted into the equation (27) by a computer to calculate the specific heat of the sample.
[0057]
In the above specific heat measurement method, no. 1, no. 2, no. 3 and no. 4 is set to a position where the thermal resistance with the soaking vessel 7 is the same, but may be set to a position where the thermal resistance is different. No. 1 in the cell, No. A standard sample with a known specific heat in cell No. 2 3 and No. 3 No. 4 cell is an empty cell, and 1, no. 2, no. 3 and no. When all four cells are empty cells, the difference between the output of the thermocouple 10 for empty cell temperature and the output of the thermocouple 8 for sample temperature, the output of the thermocouple 11 for empty cell temperature, and the standard While obtaining the difference value from the output of the thermocouple 9 for the sample temperature, No. 1 and No. No. 2 was put into both cells, and No. 2 was obtained from the above equation (36). 3 and no. Heat resistance R ₃ , R ₄ between the position 4 and the soaking vessel 7 is obtained, and the specific heat of the sample is substituted by substituting the above difference value, R ₄ / R ₃ and the specific heat value of the standard sample from the equation (42). Is calculated.
[0058]
The above three measurements need not be performed every time. If measurement is performed under the same measurement conditions (for example, heating rate, atmosphere, measurement temperature range, etc.) using the same sample cell, ΔT _{31 (1)} , ΔT _{42 (1)} , ΔT _{31 (3)} , ΔT _{Since 42 (3)} is obtained, the specific heat of the sample can be obtained by obtaining ΔT _{31 (2)} and ΔT _{42 (2)} by only one measurement.
[0059]
Note that the twin-type differential scanning calorimeter of the present invention can be effectively used for thermal identification and comparison of samples because two samples can be measured simultaneously under the same conditions when used as a simple thermal analysis.
[0060]
【The invention's effect】
The present invention can measure the specific heat in a high temperature range with high accuracy even when the temperature around the sample is not uniform. In addition, the specific heat in the high temperature range can be measured with high accuracy by reducing the number of measurements compared to the conventional measurement method.
[Brief description of the drawings]
FIGS. 1A and 1B are a cut front view and a cut plan view showing a schematic configuration of a differential scanning calorimeter according to the present invention.
FIGS. 2A and 2B are a plan view and a cross-sectional view of another example of the heat flow meter plate used in the differential scanning calorimeter according to the present invention.
FIGS. 3A and 3B are a cut front view and a cut plan view showing a schematic configuration of a conventional differential scanning calorimeter. FIGS.
FIG. 4 is a diagram illustrating the principle of another example of a conventional differential scanning calorimeter.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... 1st heat flow meter board 2 ... 2nd heat flow meter boards 3-6 ... Cell 7 ... Soaking vessel 8 ... Thermocouple for sample temperature 9 ... Thermocouple for standard sample temperature 10, 11 ... Thermocouple for empty cell

Claims (6)

A heat flux type differential scanning heat flow meter capable of measuring the temperature of each of the first cell, the second cell, the first cell and the second cell in a soaking vessel capable of raising and lowering the temperature. A first heat flow meter board having an attached temperature sensor;
A second heat flow meter plate having a third cell serving as a reference sample, a fourth cell serving as a reference sample, and a temperature sensor attached to each of the third cell and the fourth cell so as to allow temperature measurement. And
The both ends of the first heat flow meter plate and the both ends of the second heat flow meter plate are mounted in thermal contact with each other at the same position in the soaking vessel, respectively.
The first cell is one of a cell containing a sample, an empty cell, and a cell containing a standard sample;
The second cell is either an empty cell or a cell containing a standard sample;
The third cell and the fourth cell are empty cells;
A differential scanning heat flow meter that obtains specific heat of the sample based on a temperature difference between the sample, the standard sample, and the reference sample. 2. The differential scanning heat flow meter according to claim 1, wherein the first heat flow meter plate and the second heat flow meter plate are provided in the soaking vessel in a symmetrical structure and position. In the first heat flow meter plate and the second heat flow meter plate, a hole is provided around the first cell, the second cell, the third cell, and the fourth cell. The differential scanning heat flow meter according to claim 1 or 2, characterized in that A heat flux type differential scanning heat flow meter capable of measuring the temperature of each of the first cell, the second cell, the first cell and the second cell in a soaking vessel capable of raising and lowering the temperature. A first heat flow meter board having a temperature sensor attached thereto, a third cell serving as a reference sample, a fourth cell serving as a reference sample, and measuring each of the third cell and the fourth cell. A second heat flow meter plate having a temperature sensor attached thereto, wherein both ends of the first heat flow meter plate and both ends of the second heat flow meter plate are respectively connected to the soaking vessel. A differential scanning heat flow meter mounted in thermal contact at the same position inside,
When the thermal resistance between the first cell, the second cell, the third cell, and the fourth cell and the soaking vessel are all equal,
By measuring the temperature of the first cell containing the sample, the temperature of the second cell containing the standard sample, and the temperatures of the empty third cell and the fourth cell at the same time, A specific heat measurement method for determining the specific heat of a sample. In the differential scanning heat flow meter, when the thermal resistance is not equal,
A first step of simultaneously measuring the temperature of each cell when all of the first cell, the second cell, the third cell, and the fourth cell are empty;
A second step of simultaneously measuring the temperature of the first cell containing the sample, the temperature of the second cell containing the standard sample, and the temperatures of the empty third and fourth cells;
A third step of simultaneously measuring each temperature of the first cell and the second cell containing the standard sample and each temperature of the empty third cell and the fourth cell;
With
The specific heat of the sample is determined based on a temperature difference between the first cell and the third cell and a temperature difference between the second cell and the fourth cell in each step. Item 5. The specific heat measurement method according to Item 4. When the temperature difference between the first cell and the third cell and the temperature difference between the third cell and the fourth cell are already obtained by the first process and the third process,
6. The specific heat measurement method according to claim 5, wherein the specific heat of the sample is determined by only one measurement of the second process.

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