Weird gauge issue

[lemmiwinks]

So I dropped a gauge, and now it seems like the needle is zeroed in at 20 PSI. The weird thing is that the gauge still works, but I don't know how well. Is it safe to use this gauge and just assume pressure is 20 PSI less than what the dial reads?

[cwazy1]

i would assume so, but to be on the safe side, test your gauge to a correct one...an even better solution would to be just buying another gauge

[jackssmirkingrevenge]

Is it safe to use this gauge and just assume pressure is 20 PSI less than what the dial reads?

In a word, no.

[Hotwired]

My gauge lies to me all the time now.

It believes about 5-10psi is 0psig now. Possibly because I overpump the gauge by 50% over its final markings.

the gauge on the pump is fixed in so I can't replace it with something more appropriate like a 0-300psi gauge

[lemmiwinks]

In case anyone was wondering I tested it out in conjunction with a couple other gauges and it seems to be fine, just zeroed in at 20.

[Novacastrian]

I found that you can zero gauges, there is a thin strip of brass that connects the copper "bladder", the thing that actually moves when compressed air tells it to. I found that by either flattening it or extending with needle nose pliers one could zero the needle. After "fixing" it it read to within about 5psi i think. I am sure someone can find a pic or diagram of the workings of a gauge, *cough*jsr*cough...