A Novel Precision Ultrasonic Thermometer

A new type of temperature measurement apparatus is designed by utilizing the characteristic that the velocity of the ultrasonic wave varies with the temperature through the medium, with both merits low cost and high precision. This paper introduces the principle of ultrasonic thermometer and puts forward the realization of hardware and software of thermometer, and details the special software subdivision algorithm which is used to measure the ultrasonic transmission time accurately. The experimental results indicate that the thermometer achieves the measure of the ultrasonic wave transmitting time with nanosecond level. The key problems are solved in the practical application of the ultrasonic temperature measuring technology, and the resolution of the temperature measurement is better than 0.001 centigrade.