Piezoelectric Ultrasonic Sensors

Piezoelectric sensors are low cost, rugged devices that are easy to drive. They are resonant devices and are available in several frequencies, depending on application. The lower frequency devices (40KHz) are low cost and can range longer distances than the higher frequency devices. Higher frequency devices (200KHz and 125KHz) have limited range but are more precise and exhibit higher immunity to ultrasonic noise. Common applications include back-up warning sensors in automobiles, tank level and proximity sensing in dirty, dusty or wet environments.