Metering research facility program: Pulsation effects on gas turbine meters. Topical report, March 1990-January 1992

It has been demonstrated that pulsations cause over-registration at pulsation frequencies and flows which produce significant (10 percent or larger) velocity modulations at the turbine meter. Pulsation conditions which cause only pressure variations at the turbine meter do not cause turbine meter errors. Pulsations at very low frequencies (within the meter's ability to respond) also do not cause errors. However, many commonly occurring pulsation frequencies and amplitudes can cause turbine meter measurement errors. Unfortunately, it is not practical to directly measure velocity modulations at field installations to detect such conditions. Diagnostic tools for detecting the presence of pulsation and its effects on turbine meters would be extremely valuable for the gas industry. The study has evaluated a number of diagnostic approaches including a new rotor pulse period modulation method.