Air pressure gauges

MountaineerTom

MountaineerTom

LJ Enthusiast, Retired USAF Weapons Loader
Supporting Member
Ride of the Month Winner
Joined
Sep 25, 2018
Messages
5,620
Location
Sumter, SC
How do you know what to trust? I was airing up some tires on my utility trailer. I decided to check some different gauges and got these 4 readings All on the same tire. The one on the right is in the gun hooked to the air hose. I don’t know why, but I’ve always tended to trust the like silver pen style gauges the most.

The silver one on the left is a very lightweight, cheap feeling gauge. The one next to to it is probably twice as heavy and just feels like better quality.

E1F1DD51-B849-4579-A598-F5BF1C7B79AD.jpeg
 
I've been wondering the same thing for a long time. No matter which gauge you buy, no matter how good of a reputation it has, you still don't know if it's really correct. High price or cheapo junk doesn't seem to matter much.

I had 6 or 7 gauges at one point, and comparing them all, I found that none agreed exactly, but several of them clumped around the same value. I guessed that those were kinda-sorta accurate, so I used them for a while. Maybe we need to buy a couple of dozen different gauges and pick a few that read similarly. But they could still clump together around the wrong value.

Even if you get one you think is accurate-ish, drop it or bump it or use it at different temperatures, and all bets are off.

I finally bought a JACO ElitePro Digital 100PSI pressure gauge. They claim they're calibrated, but I doubt that each one is individually calibrated, probably just a test sample selected from a batch. But a digital one may be less prone to changes from bumps or temperature. It may not be right, but I think it will be fairly consistent. I'm using it as my "master", along with my closest analog gauge (which is cheapo).

More discussion here: Tire pressure - range between 4 tires?
 
  • Like
Reactions: MountaineerTom
Digital generally. Dials get screwed up if you drop them or abuse them which generally happens with off road stuff. Even the cheapest digital gauges these days are better than the general use dials or pen gauges. At low pressure general purpose mechanical gauges suck. Ironically I do use a dedicated low pressure gas line tester for quick off road pressure but it only reads 0-15 psi so it is air down only. I don't know how anybody can use a normal mechanical gauge for 6-12 psi which is what you really need.
 
  • Like
Reactions: MountaineerTom
up on the mountain. said:
I have been using a digital gage made by slime for years. It is accurate to half a pound. And i check it to my pencil gage. Both are close to spot on.
Click to expand...
Accurate to half a pound, or precise to half a pound? There is a big difference.

My digital gauge is precise to 1/10 pound, but that means nothing if it's off by a couple of pounds.
 
  • Like
Reactions: Grant Lasson and MountaineerTom
No reason for precision calibrated instruments because a couple of pounds difference is a total non issue. If a two of them generally agree then throw the worst one or two away. Good to go.
 
  • Like
Reactions: MountaineerTom
I‘ve wondered if a digital one would be more accurate. I was considering the JACO digital gauge.

pagrey said:
Digital generally. Dials get screwed up if you drop them or abuse them which generally happens with off road stuff. Even the cheapest digital gauges these days are better than the general use dials or pen gauges. At low pressure general purpose mechanical gauges suck. Ironically I do use a dedicated low pressure gas line tester for quick off road pressure but it only reads 0-15 psi so it is air down only. I don't know how anybody can use a normal mechanical gauge for 6-12 psi which is what you really need.
Click to expand...

For airing down, I was using a low pressure gauge and and just letting air out by pressing in the valve core. I’ve since bought an ARB deflator that removes and holds the core until you get to the pressure you want.

0C2E67B1-916F-4FB5-AE27-E94217C2754E.jpeg
 
MountaineerTom said:
For airing down, I was using a low pressure gauge
Click to expand...
I like those, I've read that pencil style gauges are the most robust of the mechanical types. Unfortunately over the years I've had a few that weren't so great but they are cheap and easy to test.

I have several dirt cheap and expensive digital gauges. They all read as close to perfect as I am able to test. It's all about form factor in my opinion.
 
  • Like
Reactions: MountaineerTom
Pencil gauges are what I started with in the 80s. I've always found them to give different results depending on how you hold them (horizontally vs vertically), and they're harder to read quickly than a dial gauge. I like my Accu-Gage RH60X, which has a protective rubber shell, a small length of hose, and a bypass to let air out. I don't baby it, but I'm careful not to drop it or let it bang around. I also have a Viair 90056, which only goes up to 35, and it gets very different results from the Accu-Gage. 😕

I didn't realize that digitals were more precise, but I avoid them because I prefer the simplicity (no batteries) of analog for something that sits in the vehicle for extended periods.
 
RMETeeJay said:
Pencil gauges are what I started with in the 80s. I've always found them to give different results depending on how you hold them (horizontally vs vertically), and they're harder to read quickly than a dial gauge. I like my Accu-Gage RH60X, which has a protective rubber shell, a small length of hose, and a bypass to let air out. I don't baby it, but I'm careful not to drop it or let it bang around. I also have a Viair 90056, which only goes up to 35, and it gets very different results from the Accu-Gage. 😕

I didn't realize that digitals were more precise, but I avoid them because I prefer the simplicity (no batteries) of analog for something that sits in the vehicle for extended periods.
Click to expand...
That’s one thing I didn’t like also with the digitals, keeping up with batteries. However, I did order a JACO digital inflator with gauge and a JACO digital stand alone gauge just to keep in the workshop.
 
Some digital gauges have really nasty little batteries, expensive to replace and they run down fast. One of my reasons for buying a specific JACO gauge was that it used AAA batteries.
 
  • Like
Reactions: MountaineerTom
Every time I get a digital gauge out it's dead so now I stick with mechanical air gauges.
For general purpose I like Milton stick style gauges because they are quality made in the USA. I like a dial mechanical gauge for the Jeep.
It's worth noting that mechanical gauges are most accurate in the middle area of their range so buy your gauge accordingly and don't buy more range than necessary.
 
  • Like
Reactions: Blondie70 and MountaineerTom
MountaineerTom said:
I‘ve wondered if a digital one would be more accurate.
Click to expand...
flyinfish said:
Every time I get a digital gauge out it's dead
Click to expand...

I am not impressed with my digital ARB, it won't report on PSI <6.5 - so it's just generally frustrating as I want to know sometimes what my tires burp down to when I go really low for more technical trails. They also have battery issues, especially in the cold, and I assume use non-standard batteries.

I 100% intend to get analog gauges this year.
 
  • Like
Reactions: MountaineerTom and flyinfish
Top Bottom
Back