This standard is applicable to the measurement of dielectric loss tangent tanδ of pyroelectric materials. GB 11297.9-1989 Test method for dielectric loss tangent tanδ of pyroelectric materials GB11297.9-1989 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for dlelectric tangent orless angle of pyroelectric material
Test method for dlelectric tangent orless angle of pyroelectric materialThis standard is used to measure the dielectric loss tangent tan of pyroelectric material. 1Terms and termsUnC: 621.315. 592+621. 317.3GR11297.9-89The terms and terms used in this standard comply with: GB11291 "Common terms and terms for semiconductor optoelectronic materials and thermoelectric materials in infrared detection materials"
2Test principle
The electric energy loss caused by the heat generated by any dielectric (including pyroelectric materials) under the action of an alternating electric field is called dielectric loss. The factor that measures the size of this loss is tan, which is called the tangent of the dielectric loss angle and is a dimensionless physical quantity. It represents the ratio of active power P to reactive power.
Measurement and calculation of dielectric loss tangent tan? There are two equivalent circuits. Figure 1 shows the two equivalent circuits and the diagram.
Approved by the Ministry of Machinery and Electronics of the People's Republic of China on October 9, 1988 and implemented on January 1, 1990
Parallel equivalent circuit
\Parallel equivalent circuit diagram
GB 11297. 9--89
b. Reconnected equivalent circuit
d. Series equivalent circuit diagram
Equivalent circuit and loss diagram
Total current, V, 1-total current. A, C-parallel equivalent capacitance. F, R-·parallel equivalent resistance.; I current parallel equivalent capacitance current, A: current flowing through parallel equivalent circuit, A, C series equivalent capacitance, F, R. = The equivalent resistance of the parallel connection, O: U. The equivalent resistance of the parallel connection, VU: The equivalent resistance of the parallel connection, V, 9: The current and voltage of the lossy capacitor account for a certain loss effect. As shown in Figure 1, the parallel loss tangent can be expressed as: tandn
The series loss tangent can be expressed as:
Where: tu---the angular velocity of the applied AC voltage, s-EUe
From equations (2) and (3), it can be seen that the tane value is only directly related to The test frequency is related. And because Cp, C, R:, Rs are functions of the field strength, field rate, pressure and temperature of the sample (the same is also related to other conditions), when measuring tan, the above-mentioned conditions should be clearly defined. In addition, the influence of the capacitance C generated by the test line and the sample should also be considered, which is in parallel with the sample capacitance C. According to formula 2) or formula 3), the relationship between tan and the measured value (ran) can be obtained: (ana)ak
where ( is the real capacitance of the sample, which is related to the actually measured capacitance as follows: C=C, --Cu
Therefore, equation (4) can be rewritten as: www.bzxz.net
tand -- {tsn)(1 +
Firstly measure C using the capacitance loss bridge, then measure the sample (Li (ta) and calculate the sample dielectric loss tangent tangent according to equation (6)
3 Test components
3.1 Test environment
GB 11297.9-89
The test should be carried out under constant temperature conditions with a constant temperature accuracy of ±1°C. The humidity around the sample should be less than 60% and the air pressure should be normal fire pressure. 3.2 Test sample
The sample should be in the form of a thin sheet with electrodes plated on two large surfaces. The thickness direction should be parallel to the ten pyroelectric axes with an allowable deviation of ±2°. 4 Test instruments and equipment
4.1 Test instrument
The instrument for measuring tan value can be selected from various types of capacitance loss measuring instruments, and the loss value can be read directly. The maximum measurement accuracy of the loss should not be less than 5%.
4.2 Test frequency and current The voltage
test frequency is specified as 1kHz±5%. The test voltage is converted into the field strength applied to the sample, which should generally be less than 10Vcm4.3 Sample shield box and sample fire
The test sample must be placed in a shield box for testing. The shield box can be made of copper or its alloy. The sample can be made of elastic metal, and the pressure on the sample should be small.
5 Test method
5.1 Sample treatment
5.1.1 First, clean the unplated electrode part of the sample with alcohol or ether, then short-circuit the two electrodes and let it stand in dry air for 4 h L
5.1.2 For pyroelectric materials with ferroelectricity, a DC electric field must be applied for single domain (polarization) treatment, and then the two electrodes of the sample are short-circuited. After 24 hours of static storage at room temperature, the loss can be measured. 5.2 Measurement steps
5.2.1 Separate the sample into two parts, with a distance equal to the thickness of the sample, connect the leads, and use a capacitance bridge to measure the virtual capacitance. The measured value is C5.2.2 Clamp the sample with a sample clamp and put it in a shielded box. Then use a shielded cable to connect the two electrodes of the sample to the measuring instrument. The dielectric loss measurement can be carried out.
5.2.3 If it is necessary to measure the dielectric loss above or below the air temperature, the sample box can be placed in a suitable form of heater or induction device. After the temperature reaches the predetermined temperature and the temperature is kept constant for 15 minutes, the measurement can be carried out. The measured value is (tana). 5.2.4 The capacitance C- of the sample should be measured while measuring (tang). 5.3 Calculation of tan value
Substitute the measured C, C and (tan) into formula (6) to calculate the actual value of the sample loss tangent. The measurement error of tan
The measurement error of this method is less than 5%.
Additional remarks:
This standard was drafted by the Institute of Crystal Materials, Shandong University. The drafters of this standard are citizens.
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