Abstract
In this study, a new sensor is proposed to determine water temperature. This sensor utilizes the difference in measurement length between two laser beams. Both are the test beams, and there is no reference beam. The two beams pass mostly through equal or closely arranged paths ; therefore, the effect of mechanical vibration on the two test beams is expected to be very small. This sensor was installed on a side wall of a vessel. The temperature near the sensor was also measured with a thermocouple as a reference. The response of the thermocouple was enough to follow the change in water temperature because the speed of temperature is very slow. This paper focuses on the confirmation and evaluation of this system of temperature measurement. The temperature measured with this system agreed well with that measured with a thermocouple. It was confirmed that this sensor system is useful for detecting changes in water temperature.
