METHOD AND DEVICE FOR ULTRASONIC MEASUREMENT OF SIZE

摘要

PURPOSE:To take a safe, high-precision measurement in nuclear power facilities, etc., by providing an ultrasonic wave reflector between a size measuring probe and a body to be measured, and taking the size measurement on the basis of an echo from the reflector as a reference point. CONSTITUTION:A synchronizing signal N1 generated by a synchronizing signal generating circuit 3 is sent to a transmitter circuit 5 through a cable. A transmit voltage P1 is generated there and used to emit an ultrasonic wave from the size measuring probe 2a. A part of the ultrasonic wave emitted by the size measuring probe 2a is reflected by the reflector 9a to generate a reflected echo Q1, which is detected by the size measuring probe 2a; the remainder is reflected by the internal surface of a pressure tube 1 and detected as an echo signal S1 again by the size measuring probe 2a. A size measuring circuit 4 regards the echo signal Q2 as a reference signal to start a time measurement and also finishes the time measurement by a echo signal S2.