High-precision pyroelectric coefficient testing device

Abstract

The utility model discloses a high-precision pyroelectric coefficient testing device which comprises an industrial personal computer, a temperature controller, a high-resistance meter, a test board, an electric heating piece, a temperature sensor and a silver paste electrode used for placing a pyroelectric material to be tested. According to the testing device, the tested pyroelectric material is heated by using a silver paste electrode heating method, so that the defects of environmental error caused by charge of insulating oil in an oil bath heating process, hydrothermal solution splashing and the like are avoided; the high-resistance meter capable of switching different measuring ranges according to the quantity of the measured electric charges is used for replacing an integrating capacitor and an electrometer to collect the pyroelectric charges, and the problems that the testing precision is reduced due to the fact that the integrating capacitor is too large, and the testing range is out of range due to the fact that the integrating capacitor is too small are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of pyroelectric coefficient testing, and more specifically to a high-precision pyroelectric coefficient testing device for pyroelectric materials. Background Art

[0002] Pyroelectric materials will change their electric polarization due to temperature changes. This phenomenon is called the pyroelectric effect, and materials with this effect are called pyroelectric materials. Pyroelectric materials are mainly used in the field of infrared detection. Pyroelectric infrared detectors made of pyroelectric materials have the advantages of no need for refrigeration, can work at room temperature, and have a wide spectral response, which has promoted the development and application of pyroelectric materials and discovered and improved some important pyroelectric materials. The size of the pyroelectric coefficient P is one of the basic parameters for evaluating pyroelectric materials. The measurement of the pyroelectric coefficient of pyroelectric materials is particularly important. Therefore, the development of its test system has received more and more attention from domestic and foreign scholars.

[0003] At present, the standard test of pyroelectric coefficient mainly refers to the charge integration method mentioned in GB / T 3389-2008. This method mainly measures the tiny pyroelectric charge accumulated at both ends of the capacitor to determine the change law of residual polarization with temperature. However, this method has the following problems: the charge amount does not change significantly with temperature, the oil bath heating process has nonlinear temperature rise and the oil bath medium itself carries the charge to introduce environmental errors, the test accuracy is not matched due to the integral capacitor capacitance, and the electrometer test range is limited. In addition, the electrical performance measurement of materials in high and low temperature environments, especially the measurement of weak signals, is affected by factors such as temperature, electromagnetic shielding, power grid harmonics, test environment, measurement wires, and electrode size, and there are large errors. In particular, the verification of instruments in high and low temperature environments is subject to the constraints of high cost of detection equipment and measurement conditions. The current methods and standards have certain shortcomings, which leads to reduced reliability of measurement data.

[0004] Therefore, how to provide a high-precision pyroelectric coefficient testing device is a problem that technical personnel in this field urgently need to solve. Utility Model Content

[0005] In view of this, the utility model provides a high-precision pyroelectric coefficient testing device.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A high-precision pyroelectric coefficient test device, comprising: an industrial computer, a temperature controller, a high resistance meter, a silver paste electrode for placing the pyroelectric material to be tested, a test bench, an electric heating element, and a temperature sensor;

[0008] The industrial computer is electrically connected to the temperature controller and the high resistance meter;

[0009] The silver paste electrode is placed on the test bench, and the silver paste electrode is electrically connected to the high resistance meter;

[0010] The test bench is provided with the electric heating element for heating the silver paste electrode, and the electric heating element is electrically connected to the temperature controller;

[0011] The temperature sensor is installed on the test bench and is used to measure the temperature of the pyroelectric material being tested. The temperature sensor is electrically connected to the temperature controller.

[0012] It can be known from the above technical scheme that compared with the prior art, the utility model discloses a high-precision pyroelectric coefficient testing device. During the test, the pyroelectric material to be tested is placed on the silver paste electrode, the industrial computer controls the temperature controller to work, the temperature controller controls the electric heating element to heat the silver paste electrode, and then heats the pyroelectric material to be tested. The pyroelectric material to be tested releases electric charges due to temperature changes, and the charges are conducted to the high resistance meter through the silver paste electrode and recorded by the industrial computer. The temperature sensor measures the temperature of the pyroelectric material to be tested, and sends the detected temperature information to the temperature controller, which is recorded by the industrial computer. The industrial computer calculates the pyroelectric coefficient of the pyroelectric material to be tested at different temperatures.

[0013] The test device uses the silver paste electrode heating method to heat the pyroelectric material under test. Compared with the traditional oil bath heating, it can avoid the disadvantages of environmental errors introduced by the charge of the insulating oil itself and hot liquid splashing during the oil bath heating process. Therefore, the silver paste electrode heating avoids the problem of charge precipitation from the insulating oil due to heating, which can improve the test accuracy and can reach a higher test temperature than oil bath heating. It can provide more precise temperature control during the heating process, allowing testing and experiments within a narrower temperature range; and, a high resistance meter that can switch to different ranges according to the measured charge amount is used instead of the integrating capacitor and the electrometer to collect the pyroelectric charge, avoiding the problems of reduced test accuracy due to excessively large integrating capacitance and test over-range due to too small integrating capacitance.

[0014] Furthermore, a test cavity is provided at the top of the test bench, a cantilever plate is installed on the cavity opening of the test cavity, the silver paste electrode comprises: a lower silver paste electrode column and an upper silver paste electrode column which are arranged opposite to each other and are both electrically connected to the high resistance meter, the lower silver paste electrode column is fixed on the bottom surface of the test cavity, the upper silver paste electrode column is fixed on the free end of the cantilever plate, and the pyroelectric material to be tested is clamped between the lower silver paste electrode column and the upper silver paste electrode column;

[0015] The electric heating element is inserted into the lower silver paste electrode column, or the electric heating element is wound around the lower silver paste electrode column.

[0016] The beneficial effect of adopting the above technical solution is that the pyroelectric material to be measured is clamped between the lower silver paste electrode column and the upper silver paste electrode column, so that the bottom end surface and the top end surface of the pyroelectric material to be measured can fully contact the silver paste electrode, ensuring the heating effect of the pyroelectric material to be measured, and also facilitating the charge released by the pyroelectric material to be measured due to temperature changes to be fully conducted to the silver paste electrode, ensuring the adequacy of charge conduction.

[0017] Furthermore, it also includes a cooling system for providing a low-temperature test environment for the pyroelectric material to be tested, and the cooling system is electrically connected to the temperature controller.

[0018] The beneficial effect of adopting the above technical solution is that when there is a need for low-temperature testing, the cooling system is used to provide a low-temperature testing environment for testing low-temperature pyroelectric materials, which can be used to study the pyroelectric properties of low-temperature pyroelectric materials. Therefore, the device can not only study the performance of high-temperature pyroelectric materials through electric heating elements, but also study the performance of low-temperature pyroelectric materials through the cooling system, which greatly improves the testing capabilities of the testing device and different testing needs.

[0019] Furthermore, the cooling system comprises:

[0020] Liquid nitrogen tank;

[0021] A liquid nitrogen cooling controller, the liquid nitrogen cooling controller is electrically connected to the temperature controller, the liquid nitrogen cooling controller is provided with a nitrogen inlet, a nitrogen outlet, and a nitrogen return port, and the nitrogen inlet is connected to the outlet of the liquid nitrogen tank;

[0022] A liquid nitrogen cooling circulation pipe is provided inside the lower silver paste electrode column, and an inlet and an outlet of the liquid nitrogen cooling circulation pipe are respectively connected to the nitrogen outlet and the nitrogen return outlet.

[0023] The beneficial effect of adopting the above technical solution is: when cooling, the liquid nitrogen cooling controller introduces low-temperature liquid nitrogen into the liquid nitrogen cooling circulation pipe through the liquid nitrogen delivery pipe, so as to achieve the purpose of cooling the silver paste electrode, that is, the pyroelectric material, and then realize the low-temperature testing function.

[0024] Furthermore, the probe end of the temperature sensor is 1-2 mm away from the surface of the pyroelectric material to be measured.

[0025] The utility model provides a high-precision pyroelectric coefficient testing method, using the testing device to perform the following testing steps:

[0026] Step S1: placing the pyroelectric material to be tested on the silver paste electrode, and then covering the test bench with a sealing cover;

[0027] Step S2: the industrial computer controls the temperature controller to work, and the temperature controller controls the electric heating element to heat the silver paste electrode to provide an ambient temperature for testing;

[0028] Step S3: the pyroelectric material under test releases charges due to temperature changes, the charges are conducted to the high resistance meter through the silver paste electrode, and are recorded by the industrial computer; the temperature sensor measures the temperature of the pyroelectric material under test, and sends the detected temperature information to the temperature controller, which is recorded by the industrial computer;

[0029] Step S4: the industrial computer calculates the pyroelectric coefficient of the pyroelectric material under test at different temperatures, and draws a curve graph showing the change of the pyroelectric coefficient with temperature.

[0030] The beneficial effects of adopting the above technical solution are: this test method uses the silver paste electrode heating method to heat the pyroelectric material to be tested. Compared with the traditional oil bath heating, it can avoid the disadvantages of the insulating oil's own charge introducing environmental errors and hot liquid splashing during the oil bath heating process. Therefore, the silver paste electrode heating avoids the problem of charge precipitation from the insulating oil due to heating, which can improve the test accuracy and can reach a higher test temperature than oil bath heating. It can provide more precise temperature control during the heating process, allowing testing and experiments within a narrower temperature range; and, a high resistance meter that can switch to different ranges according to the measured charge amount is used instead of the integrating capacitor and the electrometer to collect the pyroelectric charge, avoiding the problems of reduced test accuracy due to excessively large integrating capacitance and test over-range due to too small integrating capacitance.

[0031] Furthermore, in the step S2, the industrial computer having a built-in step heating process control curve with superimposed small heating and cooling cycles controls the electric heating element to perform step heating on the silver paste electrode.

[0032] Furthermore, the step heating process control curve is specifically a small heating and cooling cycle superimposed on a large heating process, that is, in the large heating process, the heating and cooling is controlled at a low heating rate of 2.0°C / min; in the small heating and cooling cycle, the heating and cooling is controlled at a high heating rate of 5°C / min-20°C / min, and the heating range is 10°C. The same heating rate is repeated for 3-4 small heating and cooling cycles, and then the heating rate is changed, and 3-4 small heating and cooling cycles are repeated, and so on.

[0033] The beneficial effect of adopting the above technical solution is: using a step heating method with superimposed small heating and cooling cycles, multiple small heating and cooling cycles will make the temperature change rate more obvious, avoiding the problem that the heating rate is too small to cause a significant change in the charge amount, and obtaining a more accurate measurement result. In addition, by performing multiple small heating and cooling cycles with different heating rates near a certain temperature, the impact of different heating rates on the pyroelectric coefficient test can be compared. At the same time, the test time is extended, the interference caused by the hysteresis of the pyroelectric charge change on the test can be eliminated, and the test accuracy can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0035] Figure 1 The utility model provides a structural schematic diagram of a high-precision pyroelectric coefficient testing device.

[0036] Figure 2 This is a schematic diagram of the main structure of the test bench.

[0037] Figure 3 It is a schematic diagram of the control curve of the step heating process with superimposed small heating and cooling cycles. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] Pyroelectric materials experience a change in polarization due to temperature changes. This phenomenon is called the pyroelectric effect, and materials that have this effect are called pyroelectric materials.

[0040] The pyroelectric coefficient reflects the proportionality coefficient of the response relationship of the change in the polarization intensity of the dielectric due to temperature change, and is defined by the following formula:

[0041]

[0042] Where p m is the pyroelectric coefficient, with the unit of coulomb per degree Celsius square meter [C / (℃·m2 )]; Q is the pyroelectric charge, in coulomb (C); A is the area of ​​the pyroelectric material being measured, in square meters (m 2 ) ; T is the temperature of the pyroelectric material being tested, in degrees Celsius (℃); t is the time, in seconds (s).

[0043] The basic principle of testing the pyroelectric coefficient of the pyroelectric material in the utility model is as follows:

[0044] The utility model uses a test bench to place the pyroelectric material to be tested, and controls the temperature change of the pyroelectric material to be tested in the test bench through a temperature controller. On the one hand, the test bench derives the pyroelectric charge to the high resistance meter for collection through the silver paste electrode in contact with the pyroelectric material to be tested, and on the other hand, measures the temperature of the pyroelectric material to be tested in real time through the temperature sensor. Finally, the industrial computer records the change of the pyroelectric charge of the pyroelectric material to be tested with the temperature, and calculates the curve of the change of the pyroelectric coefficient with the temperature.

[0045] Specifically, Figure 1-Figure 2 As shown, the embodiment of the utility model discloses a high-precision pyroelectric coefficient test device, including: an industrial computer 1, a temperature controller 2, a high resistance meter 3, a silver paste electrode 5 for placing a pyroelectric material 4 to be tested, a test bench 6, an electric heating element 7, and a temperature sensor 8;

[0046] The industrial computer 1 is electrically connected to the temperature controller 2 and the high resistance meter 3;

[0047] The silver paste electrode 5 is placed on the test bench 6, and the silver paste electrode 5 is electrically connected to the high resistance meter 3;

[0048] The test bench 6 is provided with an electric heating element 7 for heating the silver paste electrode 5, and the electric heating element 7 is electrically connected to the temperature controller 2;

[0049] The temperature sensor 8 is installed on the test bench 6 and is used to measure the temperature of the pyroelectric material 4 under test. The temperature sensor 8 is electrically connected to the temperature controller 2 .

[0050] Specifically, a test cavity 61 is provided at the top of the test table 6, a cantilever plate 62 is fixedly or rotatably mounted on the cavity opening of the test cavity 61, and the silver paste electrode 5 comprises: a lower silver paste electrode column 51 and an upper silver paste electrode column 52 which are arranged opposite to each other and are both electrically connected to the high resistance meter 3, the lower silver paste electrode column 51 is fixed on the bottom surface of the test cavity 61, the upper silver paste electrode column 52 is fixed on the free end of the cantilever plate 62, and the pyroelectric material 4 to be tested is clamped between the lower silver paste electrode column 51 and the upper silver paste electrode column 52;

[0051] The electric heating element 7 is inserted into the lower silver paste electrode column 51 , or the electric heating element 7 is wound around the lower silver paste electrode column 51 .

[0052] The electric heating element 7 can be a heating rod, a heating tube, etc.

[0053] The high resistance meter 3 can switch different ranges according to the size of the measured charge, avoiding the influence of the integral capacitor on the test result in the charge integration method of GB / T3389-2008, that is, if an integral capacitor with a large capacitance is used during the test, the generated pyroelectric charge will be very small, which will interfere with the measurement and reduce the test accuracy; if an integral capacitor with a small capacitance is used, although the test accuracy can be guaranteed, an over-range situation will occur, resulting in the inability to fully collect the released charge and reduce the test accuracy.

[0054] The test bench 6 is used to fix the pyroelectric material 4 to be tested, provide the required environmental temperature for the test, and can measure the temperature of the pyroelectric material 4 to be tested and derive the pyroelectric charge released by the pyroelectric material 4 to be tested. Specifically, Figure 1 , Figure 2 As shown, during the test, the pyroelectric material 4 to be tested is brought into contact with the silver paste electrode, that is, clamped between the lower silver paste electrode column 51 and the upper silver paste electrode column 52, and the test bench 6 is covered with a sealing cover. The electric heating element 7 heats the lower silver paste electrode column 51 through the instruction of the temperature controller 2, and the temperature sensor 8 records the temperature of the pyroelectric material 4 to be tested and outputs it to the temperature measurement controller 2, and is recorded by the industrial computer 1. The pyroelectric charge generated by the temperature change is output to the high resistance meter 3 through the lower silver paste electrode column 51 and the upper silver paste electrode column 52, and is recorded by the industrial computer 1. The industrial computer 1 calculates the pyroelectric coefficient of the pyroelectric material 4 to be tested at different temperatures according to the calculation formula of the pyroelectric coefficient.

[0055] In another embodiment, the high-precision pyroelectric coefficient testing device further includes a cooling system 9 for providing a low-temperature testing environment for the pyroelectric material 4 to be tested, and the cooling system 9 is electrically connected to the temperature controller 2 .

[0056] Specifically, the cooling system 9 includes:

[0057] Liquid nitrogen tank 91;

[0058] A liquid nitrogen cooling controller 92, which is electrically connected to the temperature controller 2, and is provided with a nitrogen inlet, a nitrogen outlet, and a nitrogen return outlet, and the nitrogen inlet is connected to the outlet of the liquid nitrogen tank 91;

[0059] The liquid nitrogen cooling circulation pipe 93 is disposed inside the lower silver paste electrode column 51 , and the inlet and outlet of the liquid nitrogen cooling circulation pipe 93 are connected to the nitrogen outlet and the nitrogen return outlet respectively.

[0060] When low-temperature testing of low-temperature pyroelectric materials is required, the temperature controller controls the liquid nitrogen cooling control operation, transports the liquid nitrogen in the liquid nitrogen tank to the liquid nitrogen cooling circulation pipe, cools the silver paste electrode and then cools the low-temperature pyroelectric material, thereby providing a low-temperature test environment for the test, and the liquid nitrogen flows back to the nitrogen return port of the liquid nitrogen cooling controller through the liquid nitrogen cooling circulation pipe, realizing the circulating flow cooling process of liquid nitrogen.

[0061] The temperature sensor 8 can be a thermocouple, and the probe end thereof is 1-2 mm away from the surface of the pyroelectric material 4 to be measured.

[0062] A high-precision pyroelectric coefficient test method uses a test device to perform the following test steps:

[0063] Step S1: The pyroelectric material 4 to be tested is placed on the silver paste electrode 5, i.e., clamped between the lower silver paste electrode column 51 and the upper silver paste electrode column 52, so that the pyroelectric material 4 to be tested is fully in contact with the silver paste electrode 5, and then the probe end of the temperature sensor 8 is 1-2 mm away from the surface of the pyroelectric material 4 to be tested, and finally the sealing cover of the test bench is covered;

[0064] Step S2: the industrial computer 1 controls the temperature controller 2 to work, and the temperature controller 2 controls the electric heating element 7 to heat the silver paste electrode 5 to provide an ambient temperature for the test;

[0065] Step S3: the pyroelectric material 4 under test releases charges due to temperature changes, and the charges are conducted to the high resistance meter 3 through the silver paste electrode 5 and recorded by the industrial computer 1. The temperature sensor 8 measures the temperature of the pyroelectric material 4 under test, and sends the detected temperature information to the temperature controller 2, which is also recorded by the industrial computer 1.

[0066] Step S4: The industrial computer 1 obtains a curve of the change of the pyroelectric charge with the temperature of the pyroelectric material under test by recording the pyroelectric charge collected by the high resistance meter 2 and the temperature of the pyroelectric material measured by the temperature sensor 8, and on this basis, calculates the pyroelectric coefficient of the pyroelectric material under test 4 at different temperatures according to the pyroelectric coefficient formula, and draws a curve of the change of the pyroelectric coefficient with temperature.

[0067] In step S2 , the industrial computer 1 having a built-in step heating process control curve 10 with superimposed small heating and cooling cycles controls the electric heating element 7 to perform step heating on the silver paste electrode 5 .

[0068] Step temperature rise process control curve 10, see Figure 3Specifically, a small heating and cooling cycle is superimposed on a large heating process, that is, in the large heating process, the heating and cooling is controlled at a low heating rate of 2.0℃ / min; in the small heating and cooling cycle, the heating and cooling is controlled at a high heating rate of 5℃ / min-20℃ / min, and the heating range is 10℃. The same heating rate is repeated for 3-4 small heating and cooling cycles, and then the heating rate is changed, and 3-4 small heating and cooling cycles are repeated, and so on.

[0069] After the test starts, the industrial computer 1 sends the instruction to the temperature controller 2, and the temperature controller 2 controls the electric heating element 7 to heat the silver paste electrode 5 according to the temperature rise method preset by the industrial computer 1, so as to create a temperature environment that meets the requirements for the experiment.

[0070] The utility model is beneficial in that:

[0071] (1) Using a step heating method with superimposed small heating and cooling cycles, multiple small heating and cooling cycles will make the temperature change rate more obvious, avoiding the problem that the heating rate is too small to cause a significant change in the charge, and obtaining more accurate measurement results. In addition, by performing multiple small heating and cooling cycles with different heating rates near a certain temperature, the effects of different heating rates on the pyroelectric coefficient test can be compared. At the same time, the test time is extended, which can eliminate the interference caused by the hysteresis of the pyroelectric charge change on the test;

[0072] (2) The test bench uses electrode heating to heat the pyroelectric material under test. Compared with the traditional oil bath heating method, which has disadvantages such as the insulating oil itself carrying charges during the heating process, introducing environmental errors and hot liquid splashing, electrode heating avoids the problem of insulating oil precipitating charges due to heating, and can reach a higher test temperature than oil bath heating. It can provide more precise temperature control during the heating process, allowing testing and experiments to be carried out within a narrower temperature range;

[0073] (3) A high resistance meter that can switch between different ranges according to the amount of charge being measured is used to replace the integrating capacitor and the electrometer to collect the pyroelectric charge, thereby avoiding problems such as a decrease in test accuracy due to an excessively large integrating capacitor and an over-range test due to an excessively small integrating capacitor.

[0074] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0075] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-precision pyroelectric coefficient testing device, characterized in that: include: An industrial computer (1), a temperature controller (2), a high resistance meter (3), a silver paste electrode (5) for placing a pyroelectric material (4) to be tested, a test bench (6), an electric heating element (7), and a temperature sensor (8); The industrial computer (1) is electrically connected to the temperature controller (2) and the high resistance meter (3); The silver paste electrode (5) is placed on the test bench (6), and the silver paste electrode (5) is electrically connected to the high resistance meter (3); The test bench (6) is provided with the electric heating element (7) for heating the silver paste electrode (5), and the electric heating element (7) is electrically connected to the temperature controller (2); The temperature sensor (8) is installed on the test bench (6) and is used to measure the temperature of the pyroelectric material (4) being tested. The temperature sensor (8) is electrically connected to the temperature controller (2).

2. A high-precision pyroelectric coefficient testing device according to claim 1, characterized in that: The top of the test bench (6) is provided with a test cavity (61), a cantilever plate (62) is installed on the cavity opening of the test cavity (61), the silver paste electrode (5) comprises: a lower silver paste electrode column (51) and an upper silver paste electrode column (52) which are arranged opposite to each other and are both electrically connected to the high resistance meter (3), the lower silver paste electrode column (51) is fixed on the bottom surface of the test cavity (61), the upper silver paste electrode column (52) is fixed on the free end of the cantilever plate (62), and the pyroelectric material (4) to be tested is clamped between the lower silver paste electrode column (51) and the upper silver paste electrode column (52); The electric heating element (7) is inserted into the lower silver paste electrode column (51), or the electric heating element (7) is wound around the lower silver paste electrode column (51).

3. A high-precision pyroelectric coefficient testing device according to claim 2, characterized in that: It also includes a cooling system (9) for providing a low-temperature testing environment for the pyroelectric material (4) being tested, and the cooling system (9) is electrically connected to the temperature controller (2).

4. A high-precision pyroelectric coefficient testing device according to claim 3, characterized in that: The cooling system (9) comprises: Liquid nitrogen tank (91); a liquid nitrogen cooling controller (92), the liquid nitrogen cooling controller (92) being electrically connected to the temperature controller (2), the liquid nitrogen cooling controller (92) being provided with a nitrogen inlet, a nitrogen outlet, and a nitrogen return outlet, the nitrogen inlet being connected to the outlet of the liquid nitrogen tank (91); A liquid nitrogen cooling circulation pipe (93), wherein the liquid nitrogen cooling circulation pipe (93) is inserted into the lower silver paste electrode column (51), and an inlet and an outlet of the liquid nitrogen cooling circulation pipe (93) are respectively connected to the nitrogen outlet and the nitrogen return port.

5. A high-precision pyroelectric coefficient testing device according to any one of claims 1 to 4, characterized in that: The probe end of the temperature sensor (8) is 1-2 mm away from the surface of the pyroelectric material (4) being measured.

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