Ultrasonic transducer and current loop transmitter.

摘要

Ultrasonic vibrations indicating trouble at remote locations are detected by sensors (20) spaced in the vicinity of expected trouble. These sensors have weather resistant transducers that convert ultrasonic vibrations from a leak in a conduit, electrical arc, bearing vibration or the like, into an electrical signal. In the sensor there are circuits that amplify the electrical signal and transmit it with a current loop transmission system over a twisted pair of wires to a central control and analysis computer (30). The amplification of the signal at the sensor is controlled by a signal from the central computer which changes the gain increments until the sensor circuits are not saturated by the ultrasonic signal. This gain control signal is also delivered to the sensors over a twisted pair of wires (31, 33) by current loop transmission system.