Transit Time Ultrasonic Flow Meters for Natural Gas Measurement

The advantages of ultrasonic flow meters are well know — no line obstructions, large turndown ratio, bi-directionality, high accuracy — and ultrasonic meters are now widely used within the gas industry in a wide variety of applications. Ultrasonic meters are available in several different configurations ranging from high accuracy multipath spoolpiece meters to single path hot-tapped meters. While all of these meters operate on the same basic transit-time principle, there are significant differences in their operational aspects. This paper is intended to review the basic concepts of ultrasonic flow meters, to clarify the differences listed, and to explain how ultrasonic meters should be specified.