Recently I bought a tire inflater that I returned but it came with a digital cool looking gauge and I notice it read 5 psi more than the gauge I was using. I was using a 4 year old Victor I got from Autozone that I have kept inside the car. I kind of assumed the new cool looking digital one was correct.
So I bought an arguably highly rated Accutire guage
And I also bought an inexpensive pretty ebay guage from China
The Accutire gauge allows for zeroing it out. So I did that and there was a 1 psi change in readings which after that were consistent, though as I think about it more, I may have just lost 1 psi of air in the zeroing out process.
Accutire 55 psi
Victor 56.2 psi
Ebay inexpensive 50 psi
They each make consistent readings so it seems I can use each of them with an adjustment.
I am going to assume the Accutire is the most precise and keep that inside rather than exposing it to heat and cold.
Ideally it would be good to know somebody that has a calibrated gauge to test the gauge I use for my baseline.
I don't think I can assume that the pressure precision would be the same at a different pressure, like a more standard 38 psi.
By the way, the inexpensive gauge comes apart and it is like a short pencil gauge and the part that pops out pushes against the dial readout so perhaps I could shim it up to get a better reading or grind off some plastic do it goes in further.
PS I would like the change the title to use the word precision rather than accuracy. All three gauges are accurately consistent. Not sure how to change that.
Edited by obob, 10 February 2018 - 02:19 PM.