The core of an ultrasonic probe is a piezoelectric wafer in its plastic jacket or metal jacket. There can be many different materials that make up the wafer. The size of the wafer, such as diameter and thickness also varies, so the performance of each probe is different, we must know its performance in advance before use. The main performance indicators of ultrasonic sensors include:
(1) Operating frequency. Operating frequency is the piezoelectric chip *** vibration frequency. When added to its ends of the frequency of the AC voltage and wafer *** vibration frequency is equal, the output energy is the largest, the highest sensitivity.
(2) operating temperature. Because the Curie point of piezoelectric material is generally higher, especially when the diagnostic ultrasound probe using less power, so the working temperature is relatively low, can work for a long time without failure. Medical ultrasound probes have higher temperatures and require separate refrigeration equipment.
(3) sensitivity. Depends largely on the manufacturing wafer itself. High electromechanical coupling coefficient, high sensitivity; vice versa, low sensitivity.