Robust water pressure sensor?

JimS

Active Member
Have a sprinkler system that pumps from a very small creek and occasionally at the end of a dry summer it dries up.  So I have put a pressure sensor on the system to shut down if the pressure is too low.  It is after a filter so having an analog sensor provides an indication of a dirty filter but still functional and I can clean the filter.
 
Trouble is several solid state sensors have died.  It's at the end of about a 75 ft wire run and the water comes from the stream much farther away so differential voltage from lightening storms is a real issue.
 
The system runs with a Raspberry Pi so have linked that to my network by wifi to at least keep any transients out of my network cabling.
 
Thinking I may need to abandon the linear measurement and use pump pressure switches instead.  They are very robust although they may have trouble with low voltage/low current (sometimes the low voltage/low current isn't enough to overcome oxide layer on the contacts).  Have even though of trying to make a sensor from some PVC pipe, a pop up sprinkler spring and some orings - it would basically be a pop up sprinkler with the nozzle plugged and perhaps more stroke to sense lower pressures.  I could detect the plunger position various ways - optical interrupters or magnetic reed switches would work. 
 
Have even thought about using a camera aimed at a conventional gauge to detect the position of the needle.  But with the outside environment and the length of cable I think there are simpler workable ways.
 
Maybe some sort of rubber pressure bladder and measure the displacement with pressure?
 
Whatever I use has to have about a 60 second start up delay to allow the pump to raise the water to ground level and build up pressure but that can be handled in the controller.
 
Any ideas on how I might do this?
 

pete_c

Guru
Many years ago here used a Davey Booster Pump.  The one I purchased was made in Australia.  Never had an issue with it.
 
It was more of a legacy type of pump versus the one I see on Amazon.  Many safety issues and CS was great with it.
 
Davey Booster Pump
 
I originally did not have enough water pressure to drive the irrigation system using the town water feed.
 
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