Reply With QuoteThat is a lovely piece of kit and must take away the worries of wet pressure testing as you say.
....and a lot less hassle!
One of the more onerous tasks when repairing watches is the pressure testing element, I've been using a 6bar wet tester for my basic leak tests for some time - you know the machine, it's the one below. What it does it does well but it is a labour intensive time consuming process, especially when your doing watches day in and day out.
Simply preparing the wet tester, sometimes having to remove the watch strap if it's fitted, hanging the watch, sealing the pressure cylinder, pumping it up, waiting 15 minutes, releasing the pressure whilst taking pictures as proof, drying the watch afterwards then doing a condensation check takes a good 30 minutes of my time that can be better spent doing other tasks. This is without mentioning that I don't enjoy testing chronographs in a wet tester as the chances of failure are considerably higher than a basic wristwatch, and the last thing you want is the crystal blowing out once it's submerged! With this in mind I've been saving for some time to get my dream tester, a Greiner Poseidon LT-100 which is a dry tester, can test a vacuum of 0.7bar and a pressure of up to 10bar. The thought of just putting a watch in, pressing a button and walking away has been a dream of mine for ages. Well finally it's here, it was delivered today so this afternoon was spent commissioning the compressor, printer, tester and running the air lines.
This is what it looks like
And this is what powers it, a small Bambi compressor that is normally found in laboratories, dental surgeries and the like, in fact anywhere where dry, oil free air is required.
To work it you first open the chamber
Place the watch on the rest and lower the bridge
Close the chamber and choose which test you want to run, this submariner is having a 10bar waterproof test
And that's it, I can walk away and get on with other stuff now! The display shows whats happening as the tests are running, here the vacuum test is in operation
Once this is completed it moves on to the pressure test
Once this is done the machine vents and that's it, finished
The thermal printer prints out the results ready for inclusion with the receipt.
All that's left is to remove the watch ready for the next one. To say I'm pleased with it is an understatement, I've just gained back a few hours each week and that's worth every penny
That is a lovely piece of kit and must take away the worries of wet pressure testing as you say.
Great investment Duncan, i'm sure quite a few TZ'ers divers will see that piece of kit in due course!
Well done, I'm sure your hard saving will pay dividends. ;-)
R
Ignorance breeds Fear. Fear breeds Hatred. Hatred breeds Ignorance. Break the chain.
Tremendous bit of kit but it ends on era of those great wet tester shots!
Pleased you're happy with it.
Nice piece of kit.
Does this mean you now have a reasonably priced wet tester for sale?
Dave
I`m envious!.......I`d love one of these but I can`t justify it on the scale I work.
The wet tester is a flawed device, it needs using with care. I`m far happier testing built up cases without a movement in for obvious reasons! It is time-consuming to use and there's always a risk of getting water in a watch if it isn`t used with great care. I`d never put a watch in if I hadn`t already mocked up the case and tested without the movement, if there's a huge leak it can end badly.
Paul
One of the problems with the wet tester apart from the hassle and potential jeapody is the fact that air trapped in crowns, bezels and the like waits until you release the pressure to make itself known. I am sure many a minor heart attack during the first outing for first time users. My throughput will never be high enough to justify the expense of a dry tester, but that doesn't prevent me from being envious!
Martin
I'm afraid not, if the Greiner ever goes down I'll need something in reserve!Originally Posted by Dave S
At least that's saved me wondering if I have the need
Dave
Nice bit of kit Duncan.
Mmm, shiny...
How does it work? I understand the wet tester but how does the dry tester "know" if the watch has leaked?
It measures the deflection on the crystal, during the vacuum test it measures the deflection of the crystal upwards as the pressure inside the watch should be higher than in the chamber. During the pressure test it measures the deflection of the crystal downwards. The deflection it measures is miniscule, it measures to an accuracy of 0.0001mm which equates to one ten thousandth of a millimetre, 0.1 micrometre or 10 nanometres.
This is the vacuum test build up to the vacuum
And this is the graph, the deflection has to hold steady for a set amount of time, the default is 25 seconds. The screen informs me that the upward deflection is 1.8 thousandths of a millimetre.
With the pressure test the same applies, in this shot it's up to pressure and the test is running
And this is the graph, again it has to hold steady, the downward deflection here is 74.4 thousandths of a milimetre.
If the watch fails the vacuum test the pressure test won't be run, if it passes the vacuum test then fails the pressure test the decompression is dropped slowly by 2 bar at a time to prevent the crystal blowing out.
Last edited by Thewatchbloke; 12th April 2016 at 10:34. Reason: decimal point error!
Does this have any limitations? For example, if you wanted to test a Swiss Military CX, the crystal is 10mm thick - would that be expected to flex at all?
It depends how it's seated, if it's on a rubber gasket the gasket will give slightly, if it's got a nylon seal holding it in place then I'm not sure there'd be any deflection on a 10mm thick crystal. If there isn't that's when the wet tester has to be used
modern times modern solutions! Nice equipment though
Duncan,
Have you tested any CWC and Precista divers in the new machine? They both use flat mineral crystals 2.00 - 3.00 mm thick (depending on model) that sit in a hard plastic 'L' shaped gasket.
The crystal would not flex as such but would have to compress the gasket. Does it self-calibrate depending on the crystal type, thickness and method of sealing or am I missing something here?
Terry
I haven't tested any of the CWC divers yet Terry but I've done a few 4,000m Sea Dwellers. I'm not sure how thick the crystal is on one of those but it measured a deflection of 4.7µm at 10bar on the one I did yesterday. All it measures is movement of the probe from the starting set point which is touching the crystal to the end point which is when the chamber's at maximum pressure. It doesn't matter whether it's the caseback, the gasket or the crystal that's deflecting or compressing the fact is the reading won't stay steady if there's a leak and that's what it's looking for.
It looks like my Tudor had the privilege of taking your tester on it's maiden voyage, and they both passed with flying colours
very nice indeed, but does it have Netflix?
Netflix?
Duncan, many thanks for answering my question - I've been away down the Work Hole for a good few days and completely forgot that I'd posted. Curiosity satisfied and I can absolutely see the logic that even the sturdiest of cases and crystals must exhibit some flex on the micron scale, under 10+ bar.
As an aside I'm always perplexed by people who say they won't do the washing-up (say) in a 5 bar watch - when I consider the pressure in my car's rear tyres (3 bar) it seems nonsensical that a 5 bar watch would be at risk in a few inches of water. But, you pays yer money, and takes yer choice.
Extremely handy, but it doesn't test over 10 Bar? So you cannot test the "real divers" that "need" 20 Bar and over...
I can routinely test up to 300bar pressure/ 3,000m depth or 400bar pressure/ 4,000m depth with an additional clamp using my hydrostatic tester which is enough for most dive watches. I think you've missed my point in this thread
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