The observation of phase state and temperature using noninvasive ultrasonic waves.

Abstract

There are many ways to obtain temperature measurements and observe phase changes, but most rely on physical contact or a line-of-sight path with the material. Many industries ranging from oil and gas to food and beverage could expand their application space in select scenarios if a noninvasive means were available to identify the internal temperature state of a material within a confined vessel. This thesis investigates the hypothesis that the use of ultrasonic signals and the resulting time of flight and intensity of the high-frequency sound wave may be used to identify a material undergoing a phase change within a confined vessel. A wax melting experiment within a confined chamber has been designed to test this hypothesis. The results presented within this work demonstrate the viability of the method and the results for the speed of sound of a material as a function of temperature are highly repeatable and indicate a clear one-to-one ratio between the speed of sound and the temperature state.