TTFS SMS-TORK - Thermal Flow Switch

The TTFS is an SMS-TORK electronic thermal flow switch that detects flow or no-flow using a dual-resistor thermal dispersion probe, with no moving parts to wear out and an antifouling coating that resists dirt and rust build-up on the probe.

One resistor in the probe is heated as the sensing element and the other serves as an unheated reference; as flow carries heat away from the sensing resistor, the resulting resistance difference is used to detect and set the switching point. The TTFS covers water at 3 to 300 cm/s, air at 200 to 3000 cm/s and oil at 3 to 300 cm/s, at an accuracy of plus or minus 1 to 10 cm/s, with SS316L wetted parts and probe, a G1/2 or G1/4 male or M18 female process thread, and an insertion probe length selectable from 15 to 60 mm. It is rated up to 100 bar and -20 to 80 degrees C, offers relay, PNP, NPN or (on the TFS-F2/FE variant) 4-20 mA output with an M12 connector and 1 m cable, runs on 24 VDC or 110/220 VAC, and is rated IP67 with an adjustable set point via potentiometer or buttons.