The Gas Flow Measurement Unit (GFMU) is intended for commercial or operational (internal accounting) measurement of natural gas or associated petroleum gas consumption. The unit provides measurement and recording of gas volumetric flow rate and volume reduced to standard conditions, as well as determination of its quality indicators, including component composition, density, specific heat of combustion, Wobbe index, and dew point temperature for moisture and hydrocarbons.

The composition of the measuring equipment is determined by the category of the Gas Flow Measurement Unit (GFMU) depending on the measured flow rate, and by the class of the GFMU depending on its purpose.