Question What is your tolerance for error in your SPG?

[rick00001967]

i have never really givin this much thought to be honest. i have never been near empty so maybe thats why. lol
if mine was verified to be 500 psi out of whack, and it cannot be recalibrated, it goes in the garbage.

 

[broncobowsher]

I just checked a half dozen gauges. About 300 PSI spread on a 3000 PSI bottle. All read zero just fine.

 

[Jonn]

100Psi either way is fine but it’s NOT a symmetrical tolerance. Reading high is way worse than reading low!

 

[rx7diver]

I was taught a long time ago that a Bourdon tube SPG is not equally accurate across its entire range. So, there's that.

rx7diver

 

[Vicko]

On my shallow water setup I have a spg that shows 280 bars when it's at 200 and it goes from 50 bars to 0 in about 2 breaths. Considering I only use it for black water diving that's good enough for me.
Im waiting for my normal reg set spg to go bad so I can use it instead of this one.

 

[happy-diver]

Kakosi! What's your address Vicko that's ridiculous I'll send you one




Yeah, if you're checking other stuff like particular static pressures with bourdon tubes
the needle optimally, should be between eleven and two oclock, I suppose or something

All my manual stuff seems 10bar out even tank checkers, my cheap electronic gauges work well

All my intermediate pressure checkers read heaps different, thats good, from brand new, two from DGX

 

[Eric Sedletzky]

I have three G/B SPG’s and all of them read slightly different. As long as they zero out with the needle just coming to rest on the peg when the pressure finally settles to zero is what I look for. As long as the pressure is within 50-100 PSI of each other I’m fine with it.

 

[MacDuyver]

She showed you 3K on a digit gauge just after she filled the tank or hours after it was filled and as you were picking the tank up from the shop?

Get a 2nd regulator from a friend or dive buddy and see what their spg reads.

The tolerance from manufacturer is 10%. I would question anything above 200 psi when analyzed at the same time and know that one of those gauges is off.

When your regulator is depresurized, is the needle at 0 or somewhere above/below?

When I picked the tank up, she attached a gauge (analog) to it and it showed 3000.

Going to check mine today against a test set I know to is calibrated correctly.

The needle sits at 0 with no pressure but I don’t really trust that since there’s a pin at 0, which prevents it from dipping below.

I’m in the +/- 100psi is acceptable crowd. A gauge being potentially 500-600 off would explain ALOT about why I’ve recently had to cut a few dives shorter than any of the other divers.

 

[Belzelbub]

When I picked the tank up, she attached a gauge (analog) to it and it showed 3000.

How did the tank feel? If it was warm or hot, then that 3000 psi will drop as the tank cools, and it can be a significant jump.

Going to check mine today against a test set I know to is calibrated correctly.

That will work as well. At least you'll then know that there is a difference or not. If your gauge matches, then the problem is either at the shop that filled, or due to the temperature at the time of checking. The owner of the shop I use instructs his employees to overfill a bit to allow for the pressure drop as the tank cools. Generally, I drop off and pick up later, so they are at room temp. Only on one or two occasions has he had to top off.

 

[Wibble]

Is this a good time for the discussion about the accuracy of analogue vs. digital gauges?

Clue; digital isn't more accurate.