Pressure guage accuracy

[angelo_f]

Greetings

I am having trouble getting consistency on tyre pressure gauges when doing pressure tests. I mesured the tyres using the SCA guage on my air compressor which read 30psi and a ContinentalContiComfortKit http://www.tirerack.com/accessories/detail.jsp?ID=38 which also read 30psi. I just bought 2 brand new pencil SCA gauges and an SCA dial gauge, which all three read 25 psi. How do I find which is the real reading?

[Maxhead]

You could try the servo gauge or use a decent branded one to test...

[Bloodyaussie]

I have one I bought about 13 years agao and it cost $50 back then and it is what I use to double check everything... even servo's have been out by up to 10psi ?????

[threedogs]

X 2 wouldn't think SCA would have acuracy in mind, check out your local ARB,TJM or Opposite Lock shops

[taslucas]

yeah SCA doesnt stand for Super Completely Accurate lol. If youre after more accuracy go for a better quality gauge. The continental gauge looks pretty good quality. Maybe just take that and leave the sca for the kids bike?

[Maxhead]

This is one I use http://www.ebay.com.au/itm/Nissan-Patrol-Y62-Analogue-Tyre-Pressure-Gauge-GENUINE-NEW-/121066165377?pt=AU_Car_Parts_Accessories&hash=item1c301b1481&_uhb=1#ht_3148wt_1139

Its a Hafner gauge and is 100% accurate. cant go wrong for the price

[Cuppa]

I've got a Jamec Pem gauge like this (http://www.ebay.com.au/itm/JAMEC-PEM-TDR-2000-INDUSTRIAL-WHEEL-TYRE-INFLATOR-VALUED-149-/221016569217) (which came with a calibration certificate) which I use as my reference. I have often found cheap dial & pencil gauges to be inaccurate when compared.

However I was given one of those ARB deflators (http://www.justdifferentials.com/images/ARB_EZ_Tire_Deflator.jpg) for christmas & the gauge on that is spot on, matches the Jamec every time.

Cuppa

[Lieney]

I've got a Jamec Pem gauge like this (http://www.ebay.com.au/itm/JAMEC-PEM-TDR-2000-INDUSTRIAL-WHEEL-TYRE-INFLATOR-VALUED-149-/221016569217) (which came with a calibration certificate) which I use as my reference. I have often found cheap dial & pencil gauges to be inaccurate when compared.

However I was given one of those ARB deflators (http://www.justdifferentials.com/images/ARB_EZ_Tire_Deflator.jpg) for christmas & the gauge on that is spot on, matches the Jamec every time.

Cuppa

I too was given one of those ARB ones and I reckon its spot on. Same read every time and each time.
Not only that, nice and fast to air down. Not as quick as screwing on dawns, but much more accurate with an air-down IMO
My cheap pencil gauge is just that, cheap. When the end flew out, I decided to chuck it
Want accuracy within 1-2psi, spend the money. OR get it for Xmas

[angelo_f]

I decided to go to the service station that had one of those electronic air gauges / pumps and it turned out the pencil gauges were spot on with the electronic one. What I might do is compare at a few different places. I'll let you know the results.

[macca]

We used these when we raced Karts
http://www.kartbay.com.au/p/588894/kart-tyre-pressure-gauge---large-90mm.html
But I had my car serviced and the "apprentice" (a tradie wouldnt do this) pumped the tyres to 60psi and I blew the guage when I checked the tyres.
They are accurate and easy to read. But big thing as well.

[angelo_f]

On the weekend, I took my falcon down to Sydney for new tyres. Before going on the motorway, I checked the tyre pressure at a different shell station to where I previously did a comparison with their electronic gauge and it measure the same as my SCA gauge. My brother's tyre business, Harbord Tyres, has been doing tyres for more than 30 years years and their equipment is always being updated and replaced. We tested the pressure on the new tyres with the gauge which is a part of the 12 month old tyre machine, and it read 36 PSI. We then used their other premium gauge (Jamec Pem 2000 TDR), also only 12 months old to test the pressure on the same tyre. This gauge is always hung up after being used next to the hoyst, and is not the one that is used in the bays. This gauge is never man-handled or dropped and is used as their super accurate gauge - It measured 36 - exactly the same as tyre machine gauge. I then used the SCA gauge and it read 36. So my conclusion is that the SCA gauge is spot on. I believe I have been as scientific as possible and have actually come out with what I believe is a sound conclusion.

[BigRAWesty]

Ive got 4 different gauges, a pencil, an arb gauge, the gauge on my compressor and my new ironman ezy deflator.. the pencil and compressor are way off but the arb and ironman are spot on, and pretty close to the newer servo inflaters so I stick to them..

Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[Maxhead]

It measured 36 -I then used the SCA gauge and it read 36. So my conclusion is that the SCA gauge is spot on. I believe I have been as scientific as possible and have actually come out with what I believe is a sound conclusion.

Thanks for that mate. Just hope the gauge will be accurate every time you use it and also accurate in 12 months time as well. There is a reason why they are cheap

[happygu]

Angelo,

To do a proper scientific test, you need to do a range of pressure tests and record the results.

At the moment you have proved that the SCA Gauges are accurate at 36PSI, but 5PSI down at 30PSI, which I would not find comforting at all.

If you want to be able to trust these gauges, you will need to test them from 10PSI - right through to around 40PSI, at intervals of around 3PSI, and that will give you a good base to see how accurate or not they are.....then you will truly know if you need to spend some cash and buy a more accurate / relaible gauge.

Mic

[angelo_f]

Angelo,

To do a proper scientific test, you need to do a range of pressure tests and record the results.

At the moment you have proved that the SCA Gauges are accurate at 36PSI, but 5PSI down at 30PSI, which I would not find comforting at all.

If you want to be able to trust these gauges, you will need to test them from 10PSI - right through to around 40PSI, at intervals of around 3PSI, and that will give you a good base to see how accurate or not they are.....then you will truly know if you need to spend some cash and buy a more accurate / relaible gauge.

Mic

You are right - I should do those different tests. I probably will when I get back down to Sydney.

[whastie]

Yes similar problems - certainly the cheap ones all seem to give different readings. Have purchased better ones that are no different. Came to the conclusion that the best I could do is use the same one on all tyres - at least I get a consistent reading, hopefully around the mark.
There seems to be support for the ARB one so I'll get one of them in the near future.

Best of luck.

Regards
Wayne

[wouldnot]

Those cheap ebay ones suck. I've tried similar ones when I meet people on the road and there were different readings. Need to spend more than the minimum.

[angelo_f]

Angelo,
At the moment you have proved that the SCA Gauges are accurate at 36PSI, but 5PSI down at 30PSI, which I would not find comforting at all.
Mic

At 30psi, it was accurate with the electronic one at the servo, but not accurate with the two other gauges I originally tested with, which is what got me started.

[Gerry]

Good point thanks mate!