Thermal Mass Flow Measurement

Thermal Mass Flow Meters use a calorimetric principle to directly measure the mass flow of the particular gas independent of the working pressure and temperature. They are suited to most common dry gases such as compressed air, nitrogen, carbon dioxide, oxygen, argon, helium, hydrogen and methane. The flow sensors can output the instantaneous flow rate, total consumption and temperature of the gas depending on the communication method employed and the S401 and S450 series sensors can be combined with the S409 flow switch to enable separate measurement of flow and consumption in bidirectional systems. S415 is intended as an economical flow meter for air or nitrogen only. S418 is more accurate, suitable for a wider range of gases and includes an integral datalogger.