Pulse reflection type ultrasonic thickness meter

Claim 1

A pulse reflection type ultrasonic thickness meter, comprising: a. a pulse exciting circuit; b. an ultrasonic transducer controlled by said pulse exciting circuit to transmit ultrasonic pulses into an object whose thickness is to be measured and receive echo pulses from said object; c. an oscillator circuit for producing clock pulses; d. a gate circuit connected to receive the echo pulses and clock pulses; e. a counter circuit connected to receive and count clock pulses passing through the gate circuit corresponding to the time difference between the transmitted and received pulses; f. an indicator circuit connected to receive an output of said counter circuit and indicate the thickness of said object; and g. a switching circuit operating in synchronism with said pulse exciting circuit and disposed between an electrical power source and at least one of said counter circuit, pulse exciting circuit, oscillator circuit and gate circuit to connect said power source thereto during a measuring time period in which the ultrasonic transducer transmits the transmitted pulse and receives echo pulses and said counter circuit counts the clock pulses passing through said gate circuit and disconnects the power source therefrom during a subsequent sampling time period in which the indicator circuit receives the output of said counter circuit and indicates the thickness of said object.