Kobold MAS, Руководство по эксплуатации

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MAS
MAS K05/0722 page 5
6. Operating Principle
6.1 Measuring principle
The operation of the Mass Flow Meter, model: MAS, is based on the principle of
heat transport (first law of thermodynamic).
The medium flows through the bypass measuring system. Gas enters the MAS
flow body and divides into two flow paths. Part of the flow goes through the
laminar flow bypass the other part flows through the above located measuring
pipe.
Due to the differential pressure between P1 and P2 which is generated by the
laminar flow bypass element a part flow (m
1
) is separated from the main flow (m)
and guided through the sensor tube.
Two resistance temperature detectors (RTD elements) transferring a constant
amount of heat to the gas stream are mounted on the measuring tube. Under flow
conditions, the gas molecules absorb and transport the heat away from one to the
other coil. The resulting temperature difference is detected by the RTD-sensors
and evaluating by the measuring electronic into an output signal or a display
value. Since the heat is transported by gas molecules, the output signal is linear
proportional to the gas mass flow.