Can you tell something about the capillary flow sensor?
“The heart of the FLEXI-FLOW mass flow instrument is a capillary flow sensor, mounted as a bypass to the main gas flow channel. Essentially, this sensor consists of two straight silicon nitride capillaries, each with a diameter of 100 micron and a wall thickness of 1 micron. Temperature-dependent metal resistors on top act as heaters and temperature sensors.
During operation, gas enters the capillaries, is heated by the heaters, and subsequently the temperature of the gas is measured at a defined position downstream. Flowing gas transports this heat, and in the laminar flow regime inside the capillaries, the temperature difference (or its voltage difference analogy) is a direct measure of the gas flow rate.”
“This flow sensor is patented by Bronkhorst and is called Trough Chip Sensor – TCS technology. It offers a fast and stable flow sensor applied in a proven bypass construction for a reliable and accurate flow measurement. It replaces the traditional capillary tube sensor. The slogan of the FLEXI-FLOW refers to this as well; swift & stable, proven & precise.”