Inferential flow meters infer volumetric flow rate by measuring one or more dynamic properties of the flowing gas stream.
Inferential flow meters use meter calibration factors or empirical coefficients to account for the effects of parameters that are not measured.
A critical factor in the use of inferential flow meters is to understand their sensitivity to distortions in the gas flow through the meter.
For orifice meters, a GFC produces a maximum metering uncertainty of plus or minus 0.10 percent, and virtually no uncertainty for other inferential flow meters
. For turbine meters, the GFC has dramatically improved the repeatability and linearity of both conventional and helicoil turbine meters.