I have always treated my gages with care. But let's face the facts, our manifold gage sets have to endure extreme vibration, plus exposure to heat and cold as well as moisture and dirt.
And that's without ever dropping them, throwing them or otherwise abusing them on purpose.
And just how accurate are our gages?
Someone here once mentioned they calibrate their gages on a regular basis.
I for one never saw or heard of anyone doing this ritual.
Is it a good idea, of course it is.
But what gage pair would someone use to compare theirs to? And how often is this necessary?
Also, what are our standard gages rated at for accuracy?
1%, 5% .... 10% ???
It would sure be nice if we could simply take them in with us to the shop once a week or to the parts house and have them compared to a known accurate standard set of gages.
The reason I am bringing this topic up is because in recent years I have become more aware of the critical nature of our pressure measurements in the field.
Any comments would be nice.
Dice, I know you go by feel, so you dont have to post here.
compare the pressure of your gauges with your regulator
I replace my gauges every year on my birthday and give my old sets to the company apprentice, who generaly has managed to destroy the accuracy of them by blasting 500psi of Nitrogen through the low side. I keep one set in my van for special problem calls where accuracy is a must such as Ice machines.
I beat the living hell out of essentially all of my tools. If they can't take it, they weren't worth having.
The Yellow Jacket gauges with the brass cases are rated for 1% accuracy, and I have a half-dozen sets of them.
The regualr YJs are, I believe, 5%. I have tons of them.
I only use JB gauges and manifolds for two purposes:
- Double Low pressure
- Net oil pressure. (Double low sides on one manifold.) I carry 4 sets of these at all times.
- Suction core pressure drop.
- Double high pressure.
- Liquid line filter pressure drop.
- Holdback valve differential.
- Defrost differential valves.
- Any other high side app where I need to measure differential.
I check that the needles are on zero every single time, before I use them.
I actually calibrate against a CO2 regulator that I don't beat the **** out of, (and, in fact, I leave in a toolbox at the shop) once every couple months.
I rarely find them "bad".
So, if you check your zero, and don't use JB's for anythign where EXTREME accuracy is required, you'll be OK.
(The JB's get to a point in a hurry where they cannot hold a "Zero" setting, I've found.)
I don't buy gimmick manifolds, either, just plain old 3 hose Yellow Jackets.
I carry around 2 dozen sets all the time.
Like you Dave I have gauges everwhere.7 sets at least. I like 2 sets i have with the rubber around the gauges so one bump does not sent them to the trash can.
I'm not allowed to say anything.
Dose any one use Uniweld gauges? I have a set for about 12 years I replace the gauges and hoses but its one of my must trusted tools I think its more of a luck thing.
Originally posted by Diceman
I'm not allowed to say anything.
I check mine all the time, when I put them on a rack I compare them to what the transducers are saying. If there close to each other and I know that the transducers are not malfunctioning then thats what I go by.
Here's a good point, too, Bob.
Don't believe a damn thing those transducers are telling you until you check them against your gauges. A lot of techs (me included) have fallen for that little trap...
Transducers lie Thats why they have offsets.
A Diamond is just a piece of coal, that made good under pressure!
I have a set of gages too.