The performance of the ultrasonic transducer is designed and realized in the production, and the thermal enterprise is embodied in the application. The design of Ultrasonic transducer includes: (1) acoustic index design, (2) manufacturing process design, (3) Reliability design, (4) Stability design, (5) consistent design. The ultimate goal of transducer design is to meet the needs of the heat meter system in the working environment, in particular, the best signal waveform, high amplitude and steady waveform of the receiving transducer at the operating frequency point.
The main technical indexes of ultrasonic calorimeter include working frequency band, sensitivity of transmitting voltage, sensitivity of receiving voltage, directivity opening angle, insulation resistance, and working frequency point impedance. The parameters of these specifications have some effect on each other, and an optimal balance point is found at design time.
Piezoelectric elements are the core of piezoelectric transducers. Piezoelectric components are many kinds: piezoelectric single crystal, piezoelectric ceramics, PVDF, piezoelectric composite materials, glass ceramics, relaxation ferroelectric single crystal and so on. Piezoelectric ceramic has the advantages of low price, superior piezoelectric performance, wide variety, high mechanical strength, easy forming, mature process and stable performance, which occupies the dominant position in the field of piezoelectric transducer.
According to the current frequency of the ultrasonic energy meter transducer, the piezoelectric element is mainly used in the thickness mode. Transducer has three parts: support seat, piezoelectric ceramic, radiant surface, looks very simple, but there are still a lot of design, process problems need to be resolved.
The ultrasonic transducer is used in pairs, to get the best resonant waveform, we need to find an optimal frequency point between the transmitter voltage sensitivity curve and the receiving sensitivity curve, which is determined by the working frequency, usually slightly lower than the working frequency, which is an important principle of transducer design. The design of the ultrasonic transducer is determined by the characteristics of the transceiver system, the system operating frequency, the frequency of the device and the frequency of the piezoelectric element have a mutual relationship, the design of the ultrasonic transducer is the system design, not the choice of piezoelectric tablet.
Development of Ultrasonic Transducer
The design of ultrasonic transducer to be manufactured, the realization of reliability, stability and the consistency of mass production is a matter of great concern to manufacturers, which requires a lot of effort in the process.
First choose the right material, the core is the selection of piezoelectric functional materials, piezoelectric ceramics have many varieties, we must choose the thermal stability, pressure stability can be strong varieties; non-functional materials including encapsulated polymer materials and metal materials temperature and pressure stability to be reliable; the choice of adhesive is also very important.