To provide a propagation time measurement system capable of easily and precisely measuring the propagation time of ultrasonic waves without requiring synchronization between an ultrasonic waves transmitter and an ultrasonic waves receiver for measuring the temperature of a space to be measured based on the speed of sound waves propagating in the air.
A second sensor unit receives ultrasonic waves transmitted from a first sensor unit and transmits the ultrasonic waves to the first sensor unit after a predetermined fixed waiting time has elapsed from the reception time of the ultrasonic waves transmitted from the first sensor unit. The first sensor unit transmits the ultrasonic waves to the second sensor unit, receives the ultrasonic waves transmitted from the second sensor unit, and calculates the propagation time of the first ultrasonic waves based on the measured time from a point of transmission of the ultrasonic waves to the second sensor unit to a point of reception of the ultrasonic waves from the second sensor unit and the fixed waiting time.
IZUMI AKITOSHI
MATSUO SHOJIRO
FUKUDA TEPPEI
FUJIMOTO KEISUKE
KUNIMATSU KOJI
MATSUMOTO HIROYUKI
Yoshiaki Masaaki
Toshimitsu Ichikawa