Tek-Thermal 1700B Thermal Mass Flow Meter
Measuring Principle and Operation of a Thermal Mass Flow Meter
Tek-Thermal 1700B measures the gas mass flow based on Thermal Diffusion theory. One sensor measures the velocity of gas flow (Rh) and the other sensor detects the temperature shift of gas flow (Rmg). When there are two RTDs in gas flow, Rh will be heated and Rmg will sense the temperature difference. As the velocity of gas flow increases, more heat will dissipate and so the temperature read by Rh will decline.
Tek-Thermal 1700B Thermal Mass Flowmeter design is based on constant power measuring method, thus the RTD is heated on a consistent power and will be more durable and stable. Due to that, Tek-Thermal 1700B has less problem of zero-off which may cause a function failure of RTD due to overheating the term.