The Series TDFS Thermal Dispersion Flow Switch is a thermal flow switch that indicates whether flow rate is above or below a user setting with NO and NC NPN outputs.
Incorporated are two LED status indicators on opposite sides of the unit that provide visual switch indication - green when the flow is above set point, red when the flow is below setpoint.
The TDFS uses an impulse thermal dispersion measurement technique to measure flow rate where the probe is heated above the process temperature, and is then allowed to cool down to the process temperature.
By design, the TDFS has no paddles or vanes that can break off into the flow media, no jams or material stopping the paddle movement, as well as no seals on movement assembly to wear or leak.