Watch Pressure Tests?

[fishrising]

My local AD has pressure tested several of my watches, and below are the results. I didn't get a chance to talk to him about the results because of the shocking number of customers in the store and he needed to help others.

But, why the difference betweeen the EXPII and GMTII? Being they are both 100m rated, why the different test pressures? Let alone a negative one for the EXPII?

Can anyone shed some light for me on what these mean?

EXPII
Test Pressure: -0.8 bar
Max Deformation: -002.6 u
Tightness Value: +2.1% /min

GMTII
Test Pressure: 5.0 bar
Mex Deformation: +15.1 u
Tightness Value: +2.6% /min

SUB
Test Pressure: 10.0 bar
Max Deformation: +58.8 u
Tightness Value: 2.6% /min

[DadsWatch72]

A bar is approximately 1 atmosphere. At 1 atmosphere (sea level) there is 14.7 psi.

For every 33 feet you decend into water, you add an atmosphere.

10 atmospheres is 330 feet/100 metres. (33 feet X 10 bar/atmospheres)

The deformation has to do with stressing of the watch at pressure. I think it means that it deforms (Sub) 58.8 u (microns) in size while under pressure. It could also be ATM (Atomic Mass Units).

Tightness Value is how much it will leak, basically.

I don't know what acceptable limits are or how to interpret these results either.

I do know you can go twice as deep with the Sub than you can with your GMT.

AND, I would not go in the water with your Exp 2.

[Jocke]

Originally Posted by fishrising

My local AD has pressure tested several of my watches, and below are the results. I didn't get a chance to talk to him about the results because of the shocking number of customers in the store and he needed to help others.

But, why the difference betweeen the EXPII and GMTII? Being they are both 100m rated, why the different test pressures? Let alone a negative one for the EXPII?

Can anyone shed some light for me on what these mean?

EXPII
Test Pressure: -0.8 bar
Max Deformation: -002.6 u
Tightness Value: +2.1% /min

GMTII
Test Pressure: 5.0 bar
Mex Deformation: +15.1 u
Tightness Value: +2.6% /min

SUB
Test Pressure: 10.0 bar
Max Deformation: +58.8 u
Tightness Value: 2.6% /min

It looks like you have 2 Rolex's and one fake.

Jocke

[fishrising]

Originally Posted by Jocke

It looks like you have 2 Rolex's and one fake.

Jocke

I sure hope not, but if it is, it is keeping better time than the two real ones!

[Jocke]

Originally Posted by fishrising

I sure hope not, but if it is, it is keeping better time than the two real ones!

Maybe it's watercooled.

Jocke

[vjb.knife]

Originally Posted by DadsWatch72

A bar is approximately 1 atmosphere. At 1 atmosphere (sea level) there is 14.7 psi.

For every 33 feet you decend into water, you add an atmosphere.

10 atmospheres is 330 feet/100 metres. (33 feet X 10 bar/atmospheres)

The deformation has to do with stressing of the watch at pressure. I think it means that it deforms (Sub) 58.8 u (microns) in size while under pressure. It could also be ATM (Atomic Mass Units).

Tightness Value is how much it will leak, basically.

I don't know what acceptable limits are or how to interpret these results either.

I do know you can go twice as deep with the Sub than you can with your GMT.

AND, I would not go in the water with your Exp 2.

I agree with most of what you have said except for these things.

I think the tightness value refers to the stress on the gasket not an expected leak rate.

I don't know how they are calculating the measure so I can't say for sure but the expected leak rate had better be zero at the rated pressure differential.

And I don't think anything is refering to atomic mass units.

[watchmaker]

These results mean nothing. Your sub was tested to 10bar or 100m, and your gmt was tested to 5 bar, or 50 meters. And your explorer was tested in a 0.8 bar vaccuum, hence the negative pressure. None of these pressures are correct, and as such with this information alone I cannot say they have passed 100%.

However, if the explorer has withstood a 0.8 ba vaccuum, it will withstand 10bar overpressure. This I know through experience, but your results don't show this.

The sub and gmt have just been tested to the wrong pressures.

OR...... You were just given whatever scraps of paper the watchmaker had handy and these results are irrelevant. Would explain the wrong pressures?!

[DadsWatch72]

"The accepted standard is now the unified atomic mass unit (symbol u), with: 1 u = 1.000 317 9 amu (physical scale) = 1.000 043 amu (chemical scale)". This could be the +58.8 u.

Gaskets and gasketed joints By John H. Bickford page #433 refers to "tightness" as (sealing).

[DRAWTOOL]

Originally Posted by DadsWatch72

AND, I would not go in the water with your Exp 2.

[vjb.knife]

Originally Posted by DadsWatch72

"The accepted standard is now the unified atomic mass unit (symbol u), with: 1 u = 1.000 317 9 amu (physical scale) = 1.000 043 amu (chemical scale)". This could be the +58.8 u.

Gaskets and gasketed joints By John H. Bickford page #433 refers to "tightness" as (sealing).

The u is a measurement in microns of the difference in the watch thickness as the gaskets are compressed by the pressure being applied, it has nothing to do with atomic mass units however you wish to define them.