July 2011, Vol. 238 No. 7

Features

How Todays Gas Ultrasonic Meter Handles Compressor Pulsations

To date, limited testing has been done to determine the effects pulsation in the gas stream may have on the ultrasonic meter’s accuracy and performance. Some previous testing does show that there may be an impact on accuracy when the frequency of the pulsation is the same as — or a multiple of — the sampling frequency of the ultrasonic meter. To more clearly understand the pulsation impact, Sick Maihak, Inc. sponsored tests conducted at the TransCanada Pipe Line Didsbury Gas Dynamic Test Facility (GDTF). The results shown in this article are for an NPS 8 – inch FLOWSIC600 4 + 1 meter, also known as the 2plex design. A series of flow rates, frequency of pu