Tire Pressure Gauges

[LeeOts]

I know tire pressures have been beat to death but this is a slightly different question.

Is there an "acceptable" tolerance for pressure gauges? I have a TST TPMS, a very old Radio Shack digital gauge and a fairly new double headed truckers' gauge. None of them agree with each other.

The RS digital is the most consistent and is within 2-3 lbs of the TPMS except one sensor that I believe has gone bonkers. It doesn't agree with anything.

The truckers' gauge is always 7-8lbs higher. I'd go with that except TST claims their sensors are calibrated to within 0.73+/- PSI and it's within 2-3 lbs of the RS.

Bottom line question: Is there a way to use my compressor to check each gauge against a known, stable pressure? Thanks.

[Skip426]

JMHO: Nothing to say the gauge on your compressor is 100% accurate.
When I was still working the Snap-On tool truck carried a " master" air pressure gauge, 5" dial and we could borrow it to check our gauges.
I'd take the truck pressure gauge to a tire store and ask them to check it against their equipment. Tire machine at our shop had a 7" gauge that was supposed to be accurate to within 0.5 %, and the foreman had it tested monthly too, by the Snap-On rep.

[LeeOts]

You're right, I don't have any confidence the gauge on the compressor is accurate. I just want to see if the 3 gauges are reasonably close to each other.

[Hikerdogs]

You can take your gauges to almost any truck tire shop and have them tested. The tire shop we use has a master calibrated gauge. Every Monday morning each employee tests their gauges against the master to be sure they register properly. If they don't they're sent out for repair. The master gauge is tested and certified on a quarterly basis.

As for the TST sensors I don't believe they are that accurate. I check our tires with a gauge (tested against the tire shop master) before we start each trip. All tires are set to exactly 88 psi. When I install the TST 507 sensors there's as much as 2 psi difference before the coach even moves. At times they register as much as 5 psi difference, but when I remove the sensors and test the pressure with the gauge they're all the same.

[tderonne]

RV Tire Safety: Gauge accuracy

[LeeOts]

Originally Posted by Hikerdogs

...As for the TST sensors I don't believe they are that accurate. I check our tires with a gauge (tested against the tire shop master) before we start each trip. All tires are set to exactly 88 psi. When I install the TST 507 sensors there's as much as 2 psi difference before the coach even moves. At times they register as much as 5 psi difference, but when I remove the sensors and test the pressure with the gauge they're all the same.

Thanks Hikerdogs, that gives me confidence I'm not seeing things. I had doubts about the accuracy of the TST system but, when I called them, they swore their system was dead on.

Originally Posted by tderonne

RV Tire Safety: Gauge accuracy

Thanks Tim, that's a good read. I'll continue to use the TPMS for keeping an eye on the tires while driving but will revert to checking with a known, tested gauge each morning.

OK, now I can tell my wife I'm not totally crazy as she often accuses me.