What are the quality identification methods of Fengming tablet manufacturers? The quality of the buzzer can be easily detected with a mechanical multimeter. The method is as follows:

Turn the multimeter to the 25V gear, gently hold both sides of the buzzer chip with the left thumb and index finger, hold two pens with the right hand, the red pen approaches the potato chip, and the black pen is placed horizontally on the surface of the buzzer chip. Then press the left thumb and index finger hard, and then relax. Two voltage signals with opposite polarity are generated on the buzzer chip, making the pointer swing to the right - return to zero - swing to the left - return to zero, The swing is about 0.1 ~ 0.15v.
If the test is repeated after changing the position of the probe, the order of pointer swing is swing to the left - return to zero - swing to the right - return to zero. Under the same pressure, the greater the swing of the pointer, the higher the sensitivity of the buzzer. If the pointer does not move, it indicates that the internal leakage or damage of the buzzer.