Campbell pressure gauge accuracy?

[user123908]

I had a 40/60 well pressure switch leaking and swapped it out with this one.

Turned the water back on and noticed it was cutting on at about 42 psi and off at about 63 psi.

Additionally, I checked empty pressure tank psi and it's set to 38.

Wondering how accurate the campbell pressure gauges are; believe it's this one. I actually had the entire tank and switch/ gauge/ brass fitting assembly in front of it replaced only a few years ago but my water supply has a very large amount of iron and sediment in it. So I'm sure that might degrade things quicker.

Should I trust the reading on the gauge and adjust the switch screws to be 40/60 on the gauge? Or should I replace the gauge as well?

Is there a way to test the accuracy of the gauge?

Thanks

 

[MicEd69]

Unless a gauge is certified, the accuracy can be all over the place. I'm assuming your system is working with these items, I would not worry about the difference between 40 to 42 PSI, or 60 to 63 PSI. Adjust the pressure switch if you want, or just use the 42 and 63 numbers.

If you have an air tank, you could use some pipe fittings and put the gauge on it and test it with one or more tire gauges.

And if you have some accessible elevation available, piping, fittings and hose, every 2.3 feet of water is equal to 1 PSI. So, if you can build a 23-foot column of water above the pressure gauge, it should show 10 PSI; a 46-foot column should show 20 PSI; etc. But I would say that is a little bit overboard.

 

[gagecalman]

Typical ±3-2-3% of span accuracy.
Accuracies with multiple percentages indicate that the accuracy varies at different reading points on the gauge. These types of gauges are most accurate in the middle half of their range. Error on a 100psi pressure gauge would be:

• 3psi or ±3% for 0-25 psi range of the gauge
• 2psi or ±2% for 26-75 psi range of the gauge
• 3psi or ±3% for 76-100 psi range of the gauge

 

[RS]

It's really hard to find gages that are very accurate unless you spend a lot of money, and it doesn't matter anyhow, what I do to confirm that the pressure tank preload is set correct is: Turn off the power to the pump, and then slowly bleed off the pressure in the system, watching the gauge, and listening for the pressure switch to click. When the switch clicks, the gauge should slowly drop about another 2 psi, and then drop quickly to zero.