超音波距離計測の微差圧計への応用とその性能

We report on a manometer with an ultrasonic distance measurement circuit which we have developed and found for practical measurements of low pressure differences in many fields. It uses a separate transmitting and receiving ultrasonic transducer pair with associated circuitary operating at 215 kHz. We explained it's structure, measurement principle and performance by comparing measurement results regarding the pressure difference (<70 mmH2O) with the results of a Gottingen manometer and high response pressure transducer. As a result, it was found that the present manometer provides measurement resolution as great as 0.01 mmH2O and that the maximum error was less than 0.2 mmH2O up to 70 mmH2O pressure difference.