A Low Power Ultrasonic Heatmeter

A solution for measuring the thermal energy based on an ultrasonic flowmeter and a resistance temperature detector is presented in this paper. The electronic module was build around a dedicated time to digital converter integrated circuit. Due to the TDC-GP2 implemented functionality, including precision temperature measurement, fire pulse generation, windowing and clock calibration it was sufficient to add a low power microprocessor MSP430 and a transducer dependant driver and receiver. A software application implements the SPI communication, measurement cycle, data processing and the user interface