The ultrasonic wave thermometer sodium test(2); A summary of ultrasonic thermometer test results for pipe-flow using an externally mounted ultrasonic transducer with acoustic guide rods

not registered ; Kokaki, Nobuhisa; not registered ; not registered; not registered 

An ultrasonic thermometer based on the temperature dependence of the velocity of sound in a medium is being developed to measure the temperature of sodium non-intrusively. The principle of the device is based on the propagation time of an acoustic pulse wave, and the back calculation of the sodium temperature. As the part of the development a test was conducted in sodium pipe-flow in order to evaluate various aspects of implementing the ultrasonic thermometer. This report describes sodium test results of the ultrasonic thermometers using acoustic guide rods and a heat-resistant, but low temperature (the 80C design use temperature) ultrasonic transducer. The results and conclusions to date are as follows: (1)The ultrasonic thermometer appears relatively insensitive to flow velocity of sodium, pressure of the cover gas and the impurity concentration in sodium. The calculated error of the measured thermometry in the experiment was approximately 2 C, a smaller value than the expected 4C of the system. (2)The ultrasonic thermometer using vertical acoustic guide rods for pipeflow has been used wherein the thermal expansion coefficient was known and with 200C as the reference temperatures. For the entire temperature range tested the difference between this and a two-point calibration approach, over the temperature range is only expected to be about 2 C. (3)The number of transmit and receive cycles from which a mean value was calculated was determined. 4)(4)The in-sodium test period was about 2 months. No noticeable change in measurement characteristics of the ultrasonic thermometer were observed. Therefore, there is growing confidence in the device and the technique as a means of thermometry for sodium pipe flow is promising.