Starting at $449.00
  • Usually ships in 2-3 weeks



  • Flow Rate Settings: 0.1 GPM to 11 GPM
  • Port Size: 1/2" to 1-1/2"
  • Body Material: 316 Stainless Steel
  • Maximum Operating Pressure: 363 PSIG
  • Operating Temperature: -14 to 140°F
  • Power on Delay Time: 15 Seconds Max (Output On)
  • Response Time: 10 Seconds Max.
  • Operating Voltage: 24 VDC or 24 VAC +/- 15%
  • Current Consumption: Less than 50 mA
  • Switch Contact Rating: 30 VAC @ 45 mA, 42 VDC @65 mA
  • Switch Logic: Normally Open
  • Ingress Protection: IP65
  • Set point Accuracy: 15%
  • Set point Differential: 20% (Max.)
  • Electrical Termination: M12 x 1 (4-Pin) (1 meter cable included)
  • Approvals: CE


The Gems FS-600 series flow switch uses proven thermal dispersion technology to provide a robust flow switch with no moving parts and without filtration. The solid state sensor is compatible with both conductive and non-conductive fluids. Suitable for fluids with particulates or slurries, the FS-600 is immune to changes in media viscosity. The straight through switch is designed for a long life and can be mounted in any orientation and can handle a wide range of flow rates. No moving parts means years of reliable service.

The FS-600 series has four port sizes from 1/2" to 1-1/2" NPTF for liquid flow settings from 0.13 to 11.00 GPM. Featuring a rugged stainless steel body, the FS-600 utilizes a simple and reliable design suitable for operating temperatures from -14 to 140°F and line pressures up to 363 psig.

The Gems FS-600 series flow switch operates on the calorimetric principle which uses the cooling effect of a flowing fluid or gas to monitor the flow rate. The sensor tip of the FS-600 flow sensor houses two transistors and a heater element. When power is applied, the tip of the probe is heated. As the fluid starts to flow, heat will be carried away from the sensor tip. Cooling of the first transistor is a function of how fast heat is conducted away by the flowing liquid. The difference in temperature between the two transistors provides a measurement of fluid velocity past the sensor probe. When fluid velocity is high, the temperature differential is small. As fluid velocity decreases, there is an increase in temperature differential. This temperature-based operating principle can reliably sense the flow of virtually any liquid or gas.


This product can be used in the following applications: