Review on Enhanced LF20 Pressure Switch with Extended Range and Accurate 10Psi±2Psi Adjustment by John Larsen

With normally open and normally closed contacts, this is a general purpose switch. It took me a while to figure out that to adjust I had to pry off the little rubber stopper at the top. Underneath is a screw that requires a hex wrench. It seems to have a wide range of settings, but I'll have to experiment to see where the limits are. I already want to order another one. Update: I've created a highly reliable tank water level sensor using these pressure switches! I use a switch for each LED on the sensor. The lights are displayed vertically and each represents one tenth of the volume in my aquarium. I set each pressure switch according to the pressure level it represents. I can see how much water is in my tank at a glance, even remotely. When water is used, the level goes down a few notches until it is turned off, so I can also use this sensor to detect leaks. I have an extra LED at the top that flashes when the pump is running. The flashing is caused by small pressure fluctuations in the charge line from the pump, which are detected by a sensitive pressure switch. There are no cables between the tank and the pressure gauge. Powered by a tiny solar panel. No more stairs leaning against my water tank! I took a length of PVC pipe and drilled and cut holes for 10 1/8" pipe. I screwed the switches into the holes. It can be placed anywhere along the pipeline and will need to be calibrated for any location you choose.