Test method of piezoelectric ceramic piece

1, voltage test method in amateur conditions, can use a multimeter to check voltage blocking the quality of the piezoelectric ceramic plate, the specific method is: Dial avometer to 2.5V DC voltage profile, left thumb and index finger gently hold pressure sides of piezoelectric ceramic piece, the right hand holding the two probe, the red pen joint metal sheet, the black pen across the ceramic surfaces, as shown in figure 1. Then the left hand thumb and index finger slightly hard pressed once, then relax, piezoelectric ceramic piece has produced two polar opposite voltage signal, so that the pointer is first right pinch, then return to zero, and then to the left before you. The swing amplitude is about 0.1~0.15V. At the same pressure, swing the greater sensitivity, piezoelectric ceramic piece is higher. If the hands do not move, that piezoelectric ceramic sheet or breakage of internal leakage. The exchange of two probe position again after the test, pointer swing sequence should be: the left Pendulum - > back to zero - > right swing - > return to zero. Mind matters: if using AC voltage grade, is not observed pointer swing, this is due to a change in the voltage signals generated by relatively slow reason. Check before, first using R * 1K or R * 10K gear measuring insulation resistance, should be infinite, otherwise the proven leakage, a piezoelectric ceramic sheet intense shock and cracks after the electric iron, available in crack in thin Xu covered solder, as can continue to use. The check when the force should not be too large, too, but not bending piezoelectric ceramic piece; do not make the table pen scratched ceramic piece, so as not to damage the film. If the pressure in the piezoelectric pottery piece has been with constant, because the charge leaks continuously, the pointer swing of it will slowly return to zero.

2 current test voltage test of piezoelectric ceramic using a multimeter 50uA block, can also check the quality of the piezoelectric ceramic piece. The circuit shown in figure 2. The red pen is connected piece of metal, black probe connected to piezoelectric ceramic surface. His hands along the axial force, with +F -F, hands should be to the right a few microamps; fingers, hands and left swinging a few microamps; power facilities and loose force time of DT, through the current microammeter average values were: I = Q/ + T, I2 = - Q/ t. Current testing method of piezoelectric ceramic piece 3 with front inverter test method introduced the piezoelectric ceramic sheet with self oscillating driving and separately excited oscillation type driving in two ways, the following is the circuit shown in figure of the piezoelectric ceramic piece designed according to second ways to check the 3 now uses a piece of CC4069 six by F1 and inverter, inverter F2 constitute the two level inverter type resistance capacitance oscillator, F3 isolation effect. Connected to a piezoelectric ceramic piece, that is composed of a complete buzzer (BZ) circuit. The numbers in the figure represent the pin number CC4069. The real election R1 470K. Adjustable resistor, C = 470pF, FR2 = 1M. Substitute it into formula (f0=0.455/ (R1C1)) is determined in the square wave output frequency of F0 is about 2kHz. Supply voltage VDD choose 6~9V. Closing the switch S, by the piezoelectric ceramic sheet should be able to sound pressure. Then gradually adjust R1, when R1 increases, fo increases, the tone up; when the R1 down, fo down, lower pitch. This method can also be frequency characteristic measurement of piezoelectric ceramic sheet.