This study was focused on determining the effects of thermal radiant energy on ultrasonic meter accuracy at flow rates less than 10% of meter capacity. A straight run ultrasonic meter installation consistent with the recommendations of AGA Report Number 9 was assembled, and arrays of heat lamps were mounted above the meter run. The heat lamp arrays were energized in banks in order to simulate different modes of shading of the meter run assembly to determine the influence of solar radiation on flow measurement at low flow rates. Observed flow measurement errors were evaluated by analysis of ultrasonic...
This study was focused on determining the effects of thermal radiant energy on ultrasonic meter accuracy at flow rates less than 10% of meter capacity. A straight run ultrasonic meter installation consistent with the recommendations of AGA Report Number 9 was assembled, and arrays of heat lamps were mounted above the meter run. The heat lamp arrays were energized in banks in order to simulate different modes of shading of the meter run assembly to determine the influence of solar radiation on flow measurement at low flow rates. Observed flow measurement errors were evaluated by analysis of ultrasonic meter diagnostic log data and through various temperature measurements on the pipe surface and measurements taken at the pipe centerline. The effectiveness of using a stepped thermowell compared to a bare RTD was also evaluated in these tests.