GB/T 2414.2-1998 Test methods for properties of piezoelectric ceramic materials Long strip transverse length stretching vibration mode
Some standard content:
Ics_31-030
National Standard of the People's Republic of China
GB/T2414.2—1998
Test methods for the properties of piezoelectric ceramicsTransverse length extension yibration mode for barPublished on November 10, 1998
Implemented on July 1, 1999
Published during the National Quality and Technical Supervision Week
GB/T 2414.2—1998
This standard is revised on the basis of GB/T2414-1981 "Test methods for the properties of piezoelectric ceramics-Radial extension vibration of mesh and transverse length extension vibration of strip". Compared with GB/T2414-1981, this standard has been revised as follows: It is separated from the radial stretching vibration mode of the disc and becomes an independent standard, named as the test method for the performance of piezoelectric ceramic materials, the stretching vibration mode of the transverse length of the strip: 2 According to the provisions of GB/T1.1-1993, the prefix is added, and the standard content and order specified in the test method as an independent standard are written. 3 The test method adds the bridge method, 4 The test environment conditions are modified; 5 Appendix A: The range of the corresponding numerical table of g: ~Af/f. is extended from 0.34 to 0.50. Appendix A of this standard is the appendix of the standard. This standard replaces the relevant content in GB/T2414-1981 from the date of implementation. This standard is proposed by the National Technical Committee for Standardization of Ferroelectric Piezoelectric Ceramics. This standard is under the jurisdiction of the National Technical Committee for Standardization of Ferroelectric Piezoelectric Ceramics. Drafting unit of this standard: Qiyi Factory.
The main drafters of this standard are Luo Shaoan, Gao Mingxian and Tian Dehui. W1 Scope
National Standard of the People's Republic of China
Test methods for properties of piezoelectric ceramics
Transverse length extension vibration mode for bar
Test methods far the properties of piezaelectrle ceramicsTransverse length extension vibration mode for barGB/T2414.2—1998
Replaces part of GB/T2414—1981
This standard specifies the test methods for dielectric, piezoelectric and elastic properties of transverse length extension vibration mode for piezoelectric ceramics. This standard is applicable to the test of parameter properties of transverse length extension vibration mode for piezoelectric ceramics. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard by reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T2413-1981 Method for measuring volume density of piezoelectric ceramic materials GB/T3389.1-1996 Vocabulary of ferroelectric and piezoelectric ceramics 3 Definitions and symbols
The definitions and symbols used in this standard are in accordance with the provisions of GB/r3389.1-1996. 4 Test principles
4.1 Equivalent circuit and characteristic frequency
The electromechanical properties of a piezoelectric ceramic vibrator vibrating freely in a single mode near its vibration frequency can be represented by the equivalent circuit diagram of Figure 1. It consists of a dynamic capacitance Ci, a dynamic inductance L, a dynamic inductance R, a magnetic parallel branch and a parallel capacitance C. Near the resonant frequency, these parameters can be considered to be independent of frequency. Figure 1 Equivalent circuit
According to the equivalent circuit shown in Figure 1, the admittance of the piezoelectric ceramic vibrator can be expressed by formula (1), Y = jaC, + R, + (oL. - 1/uc,)1
= Y. +Y
Where: Y-parallel branch admittance, Ya-jaCu.SiY,——series branch admittance, Y=R,+(aL,-17ac,)S, angular frequency, rad/s.
Approved by the State Administration of Quality and Technical Supervision on November 10, 19981
Implementation on July 1, 1999
WGB/T 2414. 2 —1998
On the conductance-susceptance coordinate plane, with the change of frequency, the series branch admittance Y, the trajectory of the under-measurement terminal is a circle. When the mechanical quality factor Q\ is large, the change in the harmonic is very small, so it can be regarded as a constant. When the dielectric loss is not considered, the circular diagram of the piezoelectric ceramic vibrator admittance Y is shown in Figure 2. Figure 2 Admittance circle diagram
From the admittance circle diagram of Figure 2, the following six characteristic rates can be obtained: f
series resonant frequency,
parallel spectral resonance frequency;
resonant frequency (susceptance equals zero);
anti-resonant frequency (susceptance equals zero);
maximum admittance frequency (minimum impedance frequency); -minimum admittance frequency (maximum impedance frequency). In general, ff.f>f(f.-f>≥(f—f)>(f.-). When the merit value M of the piezoelectric vibrator is higher, under the first-order approximation,.-=f,f.=,=f. When the merit value M is lower, (f.-f) is used instead of (f,-f.) to calculate the parameter performance, which must be modified. The approximate formula is:
Af=(f,-f)*
V1+4/M
2元F.cT[2.]
Where: M-
merit value of piezoelectric vibrator: bzxZ.net
free capacitance.F#
minimum impedance of piezoelectric vibrator,.
If M(f.-f,)/f,>1 00, the error generated by the approximate formulas (2) and (3) is less than 1%. 4.2 Test Overview
This standard uses the transmission circuit method or the bridge method to test the material properties of the transverse length extension vibration mode of the piezoelectric ceramic strip. (2)
The maximum transmission frequency Fm, minimum transmission frequency Fr, and minimum impedance Zm of the piezoelectric vibrator are measured using a transmission network. An impedance analyzer is used to measure the maximum admittance constant fm, minimum admittance frequency·f, minimum impedance 2m: or resonant frequency f., anti-resonant frequency . and resonant resistance R. of the piezoelectric vibrator.
In the first order approximation, Fm1=f.=f,-f.+f,=f.=f -f,.IZ.1=R,-R1 to obtain the parallel resonance frequency f,, parallel spectrum vibration frequency f. and dynamic resistance R,, the electromechanical coupling coefficient can be determined by calculation or by checking Appendix A (standard appendix), and other parameters of the piezoelectric vibrator can be calculated. 2
W5 Test Parts
5.1 Environmental Conditions
a) Standard atmospheric conditions for the test:
Temperature: 15℃~35℃;
Relative humidity: 45%~75%;
Air pressure: 86 kPa-106 kPa.
b) Standard atmosphere for arbitration test:
Temperature: 25℃±2℃
Relative humidity: 45%～55%:
Air pressure: 86 kPa~106 kPa.
5.2 Specimen size and requirements
GB/T 2414. 2—1998
The specimen is a long strip. The length 1, width 5 and thickness 1 of the specimen shall meet (1/6)≥10, (1/)10; the straightness shall not be greater than the tolerance of the length (or width), and the parallelism shall not be greater than the tolerance of the thickness. The two main planes are all covered with metal layers as electrodes, and the plate treatment is carried out along the thickness direction.
Recommended specimen size: 30mm×5mm×(0.7~1)mm The specimen should be kept clean and dry. According to the requirements of different porcelain materials, it should be stored for a certain period of time after polarization, and tested after 2 hours under the environmental conditions specified in 5.1.
5.3 Test signal requirements:
a) When measuring capacitance and dielectric loss + electric field strength E≤5V/mm, frequency f=1kHz+b) When measuring series resonant frequency and dynamic resistance, electric field strength E≤30mV/mm. 6 Test method
6. 1 Test of free capacitance CT and dielectric loss tangent tg 6.T.1 Test equipment and requirements
The measurement error of bridge capacitance is not more than 0.5%, and the measurement error of dielectric loss tangent is not more than 5%+1×10-6.1.2 Test procedure
Connect the sample to the bridge and directly measure its capacitance and dielectric loss tangent. 6.1.3 Test uncertainty
6. 1. 3. 1 Uncertainty of capacitance test: Uc≤±1%6.1.3.2 Uncertainty of dielectric loss test, U≤±10%. 6.2 Test of series resonant frequency f., parallel resonant frequency F and dynamic resistance R1 6.2.1 Transmission circuit method
6.2.1.1 Test circuit (--) as shown in Figure 3 3
W. GB/T 2414.2-1998
PI-signal generator; P2 frequency meter, P3, P4 voltmeter BI-sample, R, Rr·dividing resistor Rr, R-terminal resistor + Rat variable non-inductive resistor box; Cr, Crs, Ca-distributed capacitance; S1·parallel type network transmission line method test circuit Figure 3, the resistance of the dividing resistor R, matches the output impedance of the signal generator, R, ≥ 10R, Rt~
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