Thermal Dispersion Flow Switch Working Principle

The thermal dispersion flow switch is an accurate liquid flow sensor. The operating principle is based on the transfer of heat.

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The thermal dispersion flow switch comprises of two temperature sensors based on the heat transfer principle. One temperature sensor is the reference and measure the fluid temperature where the flow switch probe is immersed in the heat dispersion.

The second sensor of temperature is paced close an element of heating. As the stream is flowing. There will be differences in temperature between the two sensors.

As the fluid flow rate rises, owing to the fluid shifting past the heated sensor, there is a cooling impact. The more the flow, the more the refrigeration.

A decrease in the temperature difference between the two sensors shows that the flow rate exceeds the adjustable set point of the user. When the flow rate drops there is less cooling, which causes an increase in the temperature difference.

There is a distinction in temperature between the two sensors when liquid flows. The difference in temperature has an inverse relation to the velocity of flow (quick flowing fluids will lead in higher variations in heat and vice versa) and the same is used to detect flow.

Since the device contains no moving parts, has no wear and tear and maintains a long lifespan.

News Reporter
Instrumentation Engineer