So how exactly does a calorimetric flow switch work?

If the presence of flow in a piping system should be monitored, a calorimetric flow switch ? often known as a flow monitor ? is often used. But how does a calorimetric flow switch really work? The following post explains this in greater detail.
Calorimetric flow switches, which are often generally known as thermal flow monitors, utilize the physical laws of heat transport in flows. A distinction is actually made between two technical solutions: continuous and regulated heating.
Schematic illustration of a measuring probe for a calorimetric flow switch
Continuous heating
A flow switch which is based on the calorimetric measuring principle includes a measuring probe with two temperature sensors integrated into it (see illustration). Among the sensors is heated continuously using an integrated heating element (wire-wound) with a constant heating power and measures the temperature at the heating element. The next sensor determines the temperature of the medium in the pipe. Consequently, เพรสเชอร์เกจ occurs between the two sensors, that is registered by the electronics. The higher the flow velocity of the medium in the offing, the smaller this temperature difference is. The foundation for this may be the cooling effect of flowing media. The molecules in the medium, which are flowing past the probe tip, collect ?packages of heat? and transport them away. The more molecules flow past, the greater the cooling effect. pressure gauge 10 bar of molecules passing by increases continuously with increasing flow velocity.
Regulated heating
The measuring probe is actually identical in design: You can find two temperature sensors in the medium, one of which can be heated. In this technical solution, the heating power is regulated so that the temperature difference between the two temperature sensors is kept constant throughout. Consequently, because the flow velocity increases, the heating power must be increased in order to keep how big is the temperature difference constant. The applied heating power is thus a primary way of measuring the flow velocity in the medium.
Note
Are you experiencing further questions on the measuring principle behind the calorimetric flow switch or do you need help with the selection of such a product? In its portfolio, WIKA has a calorimetric flow switch for monitoring the flow of liquid media (model FSD-3). Your contact person will be happy to assist you to.