Yes an echo, we must be in a cyber-cave, they say imitation is the highest form of compliment, so plagiarism must be a close second, glad we agree on something, i'm still a Jawa remember
Of course, all of the foregoing assumes that 50 meters is indeed 50 meters.
I have a pretty decent collection of snap-back watches, trench watches and vintage chrono’s- water proof ratings of 0 meters. I take them off when I do dishes, I don’t wear them on the hottest of steamy days, and I keep a ziplock in my bag for if I get caught in a freak thunderstorm (which I have used a few times). My lady has taken to the same safety measures- she too has a ziplock in her purse as most of her collection is also vintage.
If I know I am going to be getting into a really wet environment, I wear my Seiko that day.
Of course, all of the foregoing assumes that 50 meters is indeed 50 meters.
Breitling website said:All Breitling products have a certain degree of water resistance, described in meters or in bars (1 bar ~ 10 m ~ approx. 33 ft). This level of water resistance refers to a technical standard, based on the pressure the watch would be exposed to, during a static immersion at a certain depth (for example 50 m / 165 ft). However, the movements of the owner (diving, jumping, swimming...), as well as the force of water in motion (shower jets, river currents, waterfalls...) can considerably increase this pressure. Therefore a water resistance level of 5 bar (50 m / 165 ft) does not entail that the watch can be worn in motion at this depth; it means the watch is intended for the corresponding activities described in the table below.
I think it's a big CYA scheme. If water ever gets in they can blame you for splashing it in the sink or some nonsense like that.
Cya scheme? What is it?
i think we've found a subject that literally will never be universally agreed upon,
does anybody draw a distinction between the atmospheric pressure a watch can undergo in a bell jar chamber machine thing, and it's ability to keep water outside of it - at it's ATM-equivalent depth in water?
If it's pressure tested in a bell jar, (correct me if i've misunderstood this) the machine measures the difference in movement of the crystal when the bell jar is first emptied of air, or evacuated to form a vacuum, and a very movement sensitive pin on an arm is set lightly on the crystal, then the jar is filled with air and pressurised, when the pin touching the crystal moves down (measured in microns i think) it means the crystal has flexed downward in response to the pressure inside the jar and the test ends. The machine records a figure in ATM to reflect what pressure was inside the jar at the time.
Then there is actually taking the watch down inside the actual wet water stuff to a depth equivalent to it's surface ATM (let's say 50 metres or 5ATM) and moving it about, surely the watch will experience water molecules being more forcefully pushed against the seals, and given time (not a pun) will let some through.
True, largely because many people don't understand it well. I'll do my best to explain it below...
There are several types of pressure testers on the market. This one is probably the most common you will see in small shops:
This type of tester involves pressurizing the watch above the water line in the chamber for a period of time, then slowly releasing the pressure in the chamber, and lowering the watch into the water. If air has leaked inside, then when the pressure outside the chamber is lower, air will leak out from the case at the source of the leak. This is the most common and easily understood type of test I think.
The second is a similar unit, but it operates without the pressure. The watch is placed into a chamber filled with water, and then a vacuum is applied to the chamber - if the watch is leaking bubbles will come out of the watch at the leak location. Rolex uses this style of tester, and I even have an old Bulova one in my basement that is similar - on that one you place the watch on a platform, cover it in a solution that form bubbles, place a dome on top, and pull a lever to create a vacuum. It's mostly useless.
Then there the dry tester that you have tried to describe here:
Your description is overly simplified, so rather than just confirm the movement of the crystal (it's not always just the crystal, but the way) these machines use very sophisticated software that takes into account many things before the test is even started. Things like diameter of the watch, type of crystal, depth rating - these are all taken into account in selecting the correct program to test the watch.
Once the test begins, the machine will watch the deflection of the case, and determine if it sees both the amount of defection it expects, but also the pattern of that deflection. It does this for both the vacuum and pressure tests, which are measured in hundredths of a micron, not microns. In other words, these machines are very sensitive.
Here is my machine after a test and a printout of the results:
The last type of test is a high pressure wet test. It abandons sophisticated machinery, and is essentially a brute force test, so you are trying to force water into the case at high pressure.
Note - this sequence of tests is done twice - first with the case empty, and then after casing with the movement inside. This is done to avoid damage due to a failure.
Their are different brands of testers - here's mine:
The process I follow involves several stages - the first is simply putting the watch in the chamber, filling it with water, putting the lid on , and letting it sit there for 30 minutes.
After 30 minutes, the pressure inside the chamber is increased to the rating of the watch, plus 25%, so in this case for a 300 m rated watch (30 bar) I use 37.5 bar, of 375 meters:
It sits at this pressure for an hour:
After an hour the pressure is removed, and again the watch sits in the water for another 30 minutes. The watch is then removed from the testing chamber, dried off, and placed on a heating unit for 30 minutes:
This is the "dynamic pressure" argument. It is brought up every time there is a discussion on water resistance. Many people just assume that moving your arms will be enough to make a significant difference to the pressure a watch experiences under water. I always challenge these people to do the math to prove their theory - I have yet to have someone take me up on that. Will you be the first?
Cheers, Al
^^^^
I am just trying to imagine those three molecules squeezing through seal and joining millions of water molecules already inside watch case.
btw speaking of water jet pushing something through seals. Have you ever seen exposed seal? Have you ever seen watch case construction?
Great info and pictures Archer, thanks,
i don't have or even know the maths to prove the theory, so a theory it will remain for now, but in my Jawa mind it made sense that if we're dealing with incremental measurements in hundredths of a micron, certainly in the direction of the quantum level of scale, then the dynamic forces exerted by arm movement while at the rated depth, contributing to water molecules (over time and more than a one off dive) making their way across the expanse of the seal, wouldn't be beyond reason, it's not a crazy notion to consider (in theory of course)
But any watch manufacturer who makes decent quality watches and state they are ok to use at a certain depth must have caveats written into their instruction manuals i presume,
After an hour the pressure is removed, and again the watch sits in the water for another 30 minutes. The watch is then removed from the testing chamber, dried off, and placed on a heating unit for 30 minutes:
Al, do you cool the crystal and look for condensation after the wet test? Or is that an old wives tale?
