ULTRASONIC SENSOR AS A MEASUREMENT DEVICE OF AIR FLOW VELOCITY IN THE PIPE

The newest innovation instruments applying ultrasonic wave have been found in this technology era. Ultrasonic wave is the sound of wave is the sound wave having frequency above 20.000 Hz and is usually used in oceanic field (SONAR), medical (USG) and industrial fields. This research measured the air velocity in pipe by using ultrasonic sensor. The ultrasonic wave used was the one which has frequency of 300 kHz. The Principle of measurement applied the method of elapsed time of ultrasonic wave (time of flight) by considering the change of ultrasonic wave when passing different air flow condition: upstream and downstream. Besides, the anemometer was used as the accuracy comparator. The result showed that accuracy was 99% and the correlation was 0.99 (very high correlation). It was concluded that the ultrasonic sensor was valid and can be used as measuring instrument of air flow velocity in pipe. (C) 2013 Jurusan Fisika FMIPA UNNES Semarang