What is the difference between ultrasonic temperature measurements and a thermocouple measurement?
Unlike thermocouples which measure temperature at a single point, ultrasound measures the integral of the temperature. Thermocouples measure temperature as heat moves into the thermal mass of the sensor, which ideally is positioned at the surface or a location within a material, thus the temperature being measured can only respond as fast as the thermal mass of the thermocouple. Ultrasonic thermometry responds at the speed of sound through an object. In order to gain thermal information on the interior of a component, a thermocouple must be drilled into the component, compromising integrity. Ultrasonic thermometry is non-intrusive and can even be non-contact which maintains the integrity of the component and thermal transport and any flow conditions. Thermocouples cannot easily reach high temperatures, while ultrasonic thermometry has been demonstrated at over 2000°C without issue. The output of a thermocouple is only a measure of the temperature that goes into the thermocouple. The ou
