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	The measuring principle of thermal mass measurement is exceptionally well suited for the measurement of gas flows. One of the key advantages is that the measurement is by and large independent of pressure and temperature. Therefore, in contrast to volumetric systems, the pressure and temperature do not have to be subjected to additional measurement. All design variants of the measuring system come with a heating element and one or more temperature measurement points. The gas flowing through draws off heat from the heating element.
	Schematic illustration of how thermal mass measurement functions
	With the 'red-y' mass flow measuring and mass flow control instruments, a constant heating capacity ensures a flow-dependent temperature difference. The measurement channel contains a temperature gauge, then a heating element followed by another temperature gauge, arrayed one after the next. The accompanying illustration demonstrates the design. When flow = 0, the heating element H distributes the warmth evenly so that the temperature difference T1 - T2 is nil. The presence of flow is accompanied by two effects that in turn yield a temperature difference: First, the temperature sensor T1 located at the entrance of the channel measures a lower temperature. This is due to the cooling of the gas as it enters the chamber. Second, the gas flowing over the heating element transports warmth to the temperature sensor T2 located past the heating element, which results in an increased temperature T2. The thus generated temperature difference is a direct measure of the mass flow.
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