Testing tire gauges

[signcrafter]

Over the years I have probably bought 40-50 tire gauges of various makes and styles. I try to buy "good" ones from the reputable makers, not the 99 cent walmart ones. I usually have a bunch of pencil style ones in the drawer and give those to relatives when they don't have one. In the garage I use a milton bayonet gage/filler, http://www.amazon.com/dp/B001O2ZS50/?tag=atomicindus08-20 and also have a bridgeport gauge made in the USA and looks to be heavy duty, 10-150 PSI, model number 40-403, not sure where I got that from. According to this if you scroll down, http://www.romppais.com/Catalog/Schrader-BridgeportCatAll.pdf , it's now sold under the amflo name as part number 903d, http://www.toolsource.com/truck-tire-pressure-gauge-metal-disp-p-77709.html. Anyway, it seems that no two gauges ever read the same! Is there a way to test these gauges? Maybe use a regulator and a dial pressure gauge coming off an airline and then a schrader valve. This should be able to compare the dial gauge to the tire gauges? Is there a way to adjust these gauges if they are off? Maybe I've just had bad luck buying these things but it sure would be nice to be able to get a couple nice ones to read the same so I could trust them better.

Any advice on tire gauges and why they never seem to read the same as another one? Other than buying another one!

 

[pipsters]

I have some US made ones and some from Taiwan. The imports all read accurately close to each other, the US ones are kinda junky. Sad to say.

 

[signcrafter]

Is there an accurate way to test these to see if they are accurate or not?

 

[pipsters]

I figure if 3 read 35 psi and one reads 40 or 30 I know which one is off...

I don't know if a way to run a hose sorry.

 

[2oolhound]

The best way is to fill the tire, check with the gage and adjust if necessary then kick the tire a couple of times to confirm.

 

[signcrafter]

The best way is to fill the tire, check with the gage and adjust if necessary then kick the tire a couple of times to confirm.

I'm hoping that's a joke!

I have some of these, http://www.mcmaster.com/#schrader-valves/=iymt2z. I also have a quality regulator/gauge on my airlines. I wonder if I regulate the air to say 30PSI and then put a quick connect onto the schrader valve I have and plug it into my regulator if I could trust the dial gauge to compare the tire gauges to?

 

[Danglerb]

If I was in a testing mood, I would rig up a manifold so I could compare several gauges at once without the leaks at connection being an issue.

Amazon has a Accutire for $7 that seems to work very well, but if you want "real" accuracy I think its bucks for a thermal compensating gauge.

 

[G1GRANDEUR]

I have Milton pencil type and it's very accurate.

 

[signcrafter]

I ended up making a fitting out of a quick disconnect and a schrader valve with male pipe threads I bought from mcmaster a while back for a different project. Here are some pics.

 

[sberry]

I also check several and am amazed at how much error is in them, used a liquid filled one, its off 10% across the whole range. 44 gives 40 etc.

 

[signcrafter]

I also check several and am amazed at how much error is in them, used a liquid filled one, its off 10% across the whole range. 44 gives 40 etc.

I too was amazed at the differences. I first thought it was because of some cheaper gauges. But then I bought decent ones and still varried in readings. Never really knew which ones to trust and which ones were off!

 

[ricleh]

This is a very accurate calibration gauge

Intercomp air gauge

 

[barney rubble]

This is a very accurate calibration gauge

Intercomp air gauge

Damn they ought to be.

 

[Exceller8]

Damn they ought to be.

You're not kidding!

 

[sberry]

I inherited a good gauge and comparison testing confirms it but I also have a manifold to test some against the other. From this thread I see the great idea to hook schrader valve to it to test some.

 

[signcrafter]

I inherited a good gauge and comparison testing confirms it but I also have a manifold to test some against the other. From this thread I see the great idea to hook schrader valve to it to test some.

What kind of manifold do you have to test them against each other?

 

[sberry]

Just some pipe t's for guages, I think I have one around somewhere with a valve bank on it too. Put valve and air connector on it, can install bushing for 1/8 if needed or add t's, I need to find schrader valve as was suggested.

 

[signcrafter]

Just some pipe t's for guages, I think I have one around somewhere with a valve bank on it too. Put valve and air connector on it, can install bushing for 1/8 if needed or add t's, I need to find schrader valve as was suggested.

I got mine from mcmaster and there is a link to it in my post #6 above.

 

[Jeeper]

Doesn't testing this against a manifold PSI gauge assume they are accurate? I am not saying they are not, but does any idea know the accuracy of these type of gauges?

 

[sberry]

As the man said, if 3 read the same and one is off the one is suspect and somewhere I have a master I have checked. Somewhere I have another pic of one with gage on regulator with m/f air connects in and out, can install it in series or hook to any line with regulated pressure in range of gage.

 

[signcrafter]

Doesn't testing this against a manifold PSI gauge assume they are accurate? I am not saying they are not, but does any idea know the accuracy of these type of gauges?

Correct. But I would trust the 100 plus dollar US made regulator/gauge over a tire gauge. Plus my thinking was to set the regulator at say 30 PSI and test a few different tire gauges to see if they read the same. If 2-3 read the same then they should be correct, if one is off then I know I have a bad one.

Nothing is going to be 100% for sure accurate but I'm not NASA(is there a NASA anymore?) but I think for home use this is one of the best ways to get an accurate as possible reading. I'm just trying to get as close as possible.

 

[t100]

you can fill up your tires at Discount Tire stores, normally it's free if they are not that busy(duh.....). they have the digital manifold setup which have the fill all 4 tires at the same time. I was told these gauges are calibrated every 90 days and pretty accurate.

let them fill it and check the pressure with your own gauge.

also, if you go to Indycar and Nascar races, you can have your gauge checked at Firestone and Goodyear trucks.

 

[signcrafter]

you can fill up your tires at Discount Tire stores, normally it's free if they are not that busy(duh.....). they have the digital manifold setup which have the fill all 4 tires at the same time. I was told these gauges are calibrated every 90 days and pretty accurate.

let them fill it and check the pressure with your own gauge.

also, if you go to Indycar and Nascar races, you can have your gauge checked at Firestone and Goodyear trucks.

While this may work I just wanted something to check my tire gauges at home. Didn't really want to drive to a tire store to have them put some air in my tires and trust the guy using it to accurately fill the tires then come home and test my gauges.

I think what I came up with is a pretty decent way to see if the tire gauges are close to what they should be. So far it works for me.

 

[Vvmvbb]

Maybe replace your reference-standard meter with one of these Flukes

Can be had for under $900 too!

 

[kiatech]

Ive had a little no name digital one I found in a abandoned locker in high school. That was 2007 and I still use it till this day. It reads the exact same as the $200 digital one from snap on so I consider it accurate.

Edit- found a picture.
Mine looks the same except it doesn't have any printing on it.