Easy to Calibrate
The DFS 5.1 control relay can be set to turn ON and OFF at any flow rate between 0.25 and 10 ft/sec (0.075 to 3 m/sec). Insert two links for separate ON/OFF set points or just one link for a Hi or Lo flow alarm. Set the relay actuation time delay from 0 to 80 seconds.

A bright LED indicator shows the relay state and a LED bargraph shows the flow rate. Electronics are housed in a watertight polycarbonate wall-mount enclosure.

The clamp-on ultrasonic sensor mounts on the outside of metal or platic pipes without cutting the pipe or shutting down flow. It works on any pipe diameter 1/2″ (12.5 mm) or larger and installs in minutes. There are no moving parts and no maintenance is required. The shielded sensor cable length is 20 ft. (6 m) and can be extended up to 500 ft. (152 m) with an optional Junction Box.

DFS 5.1 Doppler Flow Switch

• Flow Control from the Outside of Metal or Plastic Pipes
• 5 amp DPDT Control Relay
• Adjustable ON/OFF Set-Points
• Hi or Lo Flow Alarm Mode
• Adjustable Time Delay
• Relay Status LED
• Flow Rate LED bar graph