ASME MFC-21.2-2010 (R2018) PDF
This Standard establishes common terminology and gives guidelines for the quality, description, principle of operation, selection, installation, and flow calibration of thermal dispersion flowmeters for the measurement of the mass flow rate, and to a lesser extent, the volumetric flow rate, of the flow of a fluid in a closed conduit.
Multivariable versions additionally measure fluid temperature. Thermal dispersion mass flowmeters are applicable to the flow of single-phase pure gases and gas mixtures of known composition and, less commonly, to single-phase liquids of known composition. Companion standard ASME MFC-21.1 covers capillary tube type thermal mass flowmeters and controllers.