Ultrasonic sensors is using ultrasonic characteristics developed in sensor. Ultrasonic is a kind of vibration frequency of sound wave above, the change can chip in voltage under the excitation of vibrate of generation, it has higher frequencies, shorter wavelengths, diffraction small, especially directional good, can become rays and directional spread etc. Characteristics. Ultrasonic of liquid and solid penetration ability is very big, especially in sunshine opaque solid, it can penetrate tens metres deep. Ultrasonic encounter impurities or boundary surface will produce significant reflection form reflex into echo, encounter moving objects can produce doppler effect. Therefore the ultrasonic widely used in industry, national defence, biological medicine, etc.

Ultrasonic sensors main purposes：

1, automotive anti-collision radar, ultrasonic ranging system, ultrasonic promixity switches,

2, household appliances, toys and other electronic equipment of remote control device,

3, guard against theft, disaster prevention equipment of ultrasound and receivers,

4, drive midge, bug, animal purposes.

Ultrasonic sensors features:

1, high sensitivity and reliability, good stability,

2 and dust-proof, high and low temperature resistance, resistance to wet, impact resistance, resistance to vibration harsh environment conditions such as.