Coriolis meters have gained worldwide acceptance in liquid applications since the early 1980’s with an installed base of more than 400,000 units. Newer designs have increased low-flow sensitivity, lowered pressure drop, and increased noise immunity enabling performance characteristics that are similar or better than traditional metering technologies. Coriolis also has attributes that no other fluid measurement technology can achieve. Some of these attributes are the meter’s immunity to flow disturbances, fluid compositional change, and it contains no wearing parts. With more than 25,000 meters measuring gas phase fluids around the world, many national and international measurement organizations are investigating and writing industry reports and measurement standards for the technology. In December of 2003 the American Gas Association and the American Petroleum Institute co-published AGA Report Number 11 and API Manual Petroleum Measurement Standards Chapter 14.9, Measurement of Natural Gas by Coriolis Meter