Hi, I want to monitor the water pressure from our well. The sensors on Amazon have a pretty bad rap for only working a short time with water. My guess is that the sensing diaphram is not isolated from the water and corrodes easily. Justa guess though.
Mouser and Digikey want $140++ for sensors that look very similar but are probably actually designed to work with water, but that's not going to happen here.
I am wondering about an oil pressure sender unit for a car/truck as they may be made of sterner stuff and they are well under 20-bucks.
Question: Anyone know what data output they have? I can't even find how many wires they have to see if it is voltage-ref, resistance-change or what.
It's a long time since I used to mess with cars so this might be out of date information....
In my experience car oil pressure sensors are an on-off switch. On for low pressure, off when the pressure exceeds a preset threshold. Alternatively, oil pressure gauges are (were) entirely mechanical, using the oil pressure to operate a dial.
Have you actually got a sensor in mind that outputs some kind of signal that indicates oil pressure electrically, rather than just indicating that it is above or below a threshold? I can't remember seeing an oil pressure gauge in a car for many years.
Although it doesn't change my answer, I am curious what you are really asking:
I want to monitor the water pressure from our well.
I don't really see how a well has water pressure, unless you mean the pressure at some depth, in which case the pressure is proportional to the depth, being 1 tonne per square metre at a depth of 1 metre.
PerryBebbington:
I don't really see how a well has water pressure
Ahhh, you City folk. We have a 350-ft well and a 2hp pump at the bottom. At the top we have a 25-gallon pressure tank and a cut-in/cut-out switch for 30-psi to 50-psi. The pressure tank allows the pump to only run when the tank is empty and the pressure is at 30-psi. Less wear and tear on the $2000-pump with a 170-psi (approx.) start up load.
I'd like to monitor that pressure so I can see if a leak is forming. The well pumps are notorious for wearing a hole in the 1-1/2" delivery-pipe down near the pump. To see the pressure falling and no usage (overnight for instance) suggests a small hole so we can get repairs before being totally out of water one day.
When that hole is big enough, all the water escapes (around 170-psi) there instead of coming up. We are then at the mercy of the local well company schedule to come out and haul the pump up and replace the bottom pipe. A cost of around $900 for their pleasure. Water is not free out here.
WaitSome:
To see the pressure falling and no usage (overnight for instance) suggests a small hole so we can get repairs before being totally out of water one day.
Suggestion: Monitor the pump contactor and add a flowmeter on the output. If the pump runs and the flowmeter hasn't shown any activity for xx mins/hrs there may be a problem.
Automotive sensors tend to be variable resistance , 300ohm or thereabouts . If you know the part number you might be able to look it up-VDO has a good web site for its transducers.
WaitSome:
Hi, I want to monitor the water pressure from our well. The sensors on Amazon have a pretty bad rap for only working a short time with water. My guess is that the sensing diaphram is not isolated from the water and corrodes easily. Justa guess though.
Mouser and Digikey want $140++ for sensors that look very similar but are probably actually designed to work with water, but that's not going to happen here.
I am wondering about an oil pressure sender unit for a car/truck as they may be made of sterner stuff and they are well under 20-bucks.
Question: Anyone know what data output they have? I can't even find how many wires they have to see if it is voltage-ref, resistance-change or what.
Thanks
The problem is the PLUMBER who installed the pressure sensor.
The proper way is to plumb in a tee,an elbow and a nipple several inches long going vertically from the tee.
Put the sensor at the top end of the nipple and there will be air trapped in the nipple that will keep the water away from the sensor. May get some water vapor on the sensor, but if the sensor is designed for water pressure, then is should be ok.
We have a 350-ft well and a 2hp pump at the bottom. At the top we have a 25-gallon pressure tank and a cut-in/cut-out switch for 30-psi to 50-psi. The pressure tank allows the pump to only run when the tank is empty and the pressure is at 30-psi. Less wear and tear on the $2000-pump with a 170-psi (approx.) start up load.