First of all, the core component of the heat meter transducer is the piezoelectric ceramic transducer. Due to the characteristics of the piezoelectric ceramics, the performance parameters of the transducer, such as the electrostatic capacity, resonant frequency and resonant impedance of the product, will change under high voltage and high temperature conditions, while the circuit board module requires that the parameter changes of the transducer have a certain regularity. Secondly, ultrasonic heat meter needs a pair of transducers when it is used. The performance parameters of these two transducers should be in good agreement, that is, they can match. Generally, depending on the scheme of the module board, the requirements for the transducer parameters vary, with some requirements matching the transducer in terms of the electrostatic capacity of the product, while others matching the resonant frequency or impedance. In addition, the size of the transducer and the copper tube base match is also critical. If the dimensions are well matched during assembly, there will be sufficient assurance in terms of product accuracy, reception amplitude and withstand voltage.

So what methods can be used to detect piezoelectric ceramic energy exchangers?

1. Measure the resistance between the two poles with R ×10K, which should be ∞ under normal circumstances. Then gently tap the piezoelectric ceramic transducer, and the pointer should swing slightly.

2. The multimeter to switch to the dc voltage range 2. 5 v, the left thumb and index finger gently hold both sides of the piezoelectric ceramic piece, right hand holding the multimeter probes, on the red probe is connected to the sheet metal, black probe placed on ceramic surface, and then the left hand slightly press then relax, which produced in the piezoelectric ceramic piece two opposite polarity of the voltage signal, The pointer of the multimeter swings to the right first, then back to zero, and then to the left. The swing amplitude is about 0.1-0.15V. The larger the swing, the higher the sensitivity. If the multimeter pointer is stationary, it indicates that the multimeter is leaking or damaged.

Remember not to pinch the piezoelectric plate with wet hands, the multimeter in the test process can not use ac voltage to stop, otherwise the pointer can not be observed to swing, it is best to use R × L0K before the test to stop, its insulation resistance should be infinite.