Abstract: A non-contact type ultrasonic distance measuring device that includes a micro processor for controlling operation of a transducer that functions as both a sonic transmitter and receiver. Micro processor programming provides a control scheme whereby an operator can program different modes of operation into the instrument by depressing buttons arranged on a rear display panel of the instrument. Mode programming is accomplished in a manner similar to setting a digital watch, with the modes displayed in a display window. The mode programming and component operation provide a gate scheme where gate control is provided through application of gain control through three (3) amplifiers, one of which is a fourth order bandpass filter that is operated by the micro processor to provide a controlled increase in gain or "Q" as the elapsed time from a transmission becomes greater.