ATTENUATOR CIRCUIT FOR ULTRASONIC TESTING

摘要

A broad bandwidth, constant input impedance programmable attenuator circuit for use in pulse-echo ultrasonic testing is provided for attenuating an acoustic discontinuity responsive electrical signal. The attenuator circuit is programmable either by computer or manually and comprises solid state components, specifically a constant current source and unidirectional current conducting devices. The attenuator circuit exhibits both constant input impedance over a wide range of operating frequencies and immunity from varying output load conditions.