Is there a way to check your common tire gauge to see how accurate it is?
Only if you have a known good gauge to compare it to.
[list]Full service truck stop,[/list]
[list]Tire store,[/list]
[list]Instrument testing service (cost about $25).[/list]
I use the scientific method: I get several cheap, Taiwan made (better quality than the Chinese made things) gages. I check a tire air pressure with all of them. If they are all about the same, I feel safe to assume that they are all about correct enough. Any that indicates several psi different, go into the trash.
Just buy a good one. I’ve had a VDO like the one at the bottom of this page for about 25 years:
I put the cheap tire pressure gauges into three cars for their respective drivers. The more expensive gauge is nice if you have only one vehicle to “gauge”.
LOL, I keep my good one in “my car” because I’m the only one who will actually use it anyway.
Or a manometer.
This question, and it is a good one, comes up periodically. You need two tire gauges; one, a dial gauge for about $15 that you will keep as a reference inside a plastic bag or other protective container and in a safe place to occasionally compare to your gauge that you use, drop, freeze, bake, loan, let the kids use and expose to dust.
There is no guarantee that your reference gauge is accurate so you might want to compare it to several others, either your own or a combination of yours and others which may result in a consensus that may or may not be accurate. Better than that, as was mentioned, get it checked by a scientific instrument calibration service at a cost of $25 to $35 at two or three readings in the range that it will be used such as 30, 35 and 40 PSI. You need to know what it reads compared to a standard with calibration traceable to NIST. There is no need to adjust the gauge; just know what the error is and you can easily compensate for that.
A tire pressure gauge with calibration traceable to NIST may be overkill but it’s the best that you can do. Tire pressure is not particularly demanding; my guess is that for consumer use, plus or minus 2 psi from specified is good enough. From experience I can tell you that pressure gauges and other instruments that cost hundreds and thousands of dollars that are used in an industrial setting related to Underwriters Laboratories and Mil standards are typically checked yearly against reference standards traceable to NIST at no small expense.