SPG offset

[JohnN]

I have two HOG brass & glass SPGs that have taken a permanent offset. One about 120 psi (and living in my spares box) and another with about 75 psi. I have no reason to not believe the 'new' gauge offset will continue to drift upwards.

How do I know? At one point I took my AI computer (and transmitter) and compared them to the LDS precision pressure gauge and again to the SPG. . . That, plus at 1 atm, I can see the needle not at 0.

I've been told there is a mfg in Italy that builds 99% of brass & glass SPGs. Is this a common phenomenon or is the Cosa Nostra out to get me?

Should I just remember to deduct the offset (in case the AI craps out)?

 

[Bob DBF]

I would guess it depends on how close you plan on going to zero.

Did you see the gauge take on the change from its original setting, or did you just notice it was off?


Bob

 

[tbone1004]

unless you're doing penetration dives, it doesn't matter.... It's all close enough. Even if you're doing penetration dives, just stop 200psi early and you're close enough

 

[JohnN]

I would guess it depends on how close you plan on going to zero.

Did you see the gauge take on the change from its original setting, or did you just notice it was off?


Bob

It started out at 0 offset

So I'm hearing that this is 'normal'. I'm good with that, but it would seem that the only reason for a Bourdon Tube to do this is poor metallurgy. . .

 

[guruboy]

Any chance of water intrusion?

 

[JohnN]

Any chance of water intrusion?

Nope

 

[guruboy]

Does the pointer move if you hit it?

 

[JohnN]

Does the pointer move if you hit it?

Nope