Vögtlinin's thermal mass flow controllers use CMOS (Complementary metal oxyd semiconductor) technology. In the measuring method, a small heating resistor with a temperature sensor on both sides is installed in the flow channel or past the flow channel. When the gas flow is zero. The temperature of both temperature sensors is the same and when there is a flow in line T2 the temperature of the sensor is higher than T1. The higher the flow, the greater the temperature difference between the temperature sensors.
The advantages of CMOS technology are that it is independent of changes in pressure and temperature. Plus, it has no moving parts so it doesn’t wear out. Mass flow controllers have a very fast response time (50ms with meter and 150ms with controller) It also has high precision, digital electronics and the mass flow controller has excellent long-term stability. The mass flow controllers are always calibrated at the factory with the appropriate gas for the application, and the Smart Series Mass Flow Controller can be calibrated with up to ten different gases.