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Water Resistance Ratings my ass


gran

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The one and only RWG Limitcd cdition prototype from MsKing is now defogged and safe :1a:

I went to the lab and used the machine used to dry gels...put the temperature to 45C (heated perforated metal mesh to place a gel or in this case that watch on) and turned on the vacum pump for 15 minutes. The exessive moisture is now gone.

This is what the apartus looks like...gel dryer and small vacum pump :lol:

271559-3490.jpg

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The one and only RWG Limitcd cdition prototype from MsKing is now defogged and safe :1a:

This is what the apartus looks like...gel dryer and small vacum pump :lol:

Nice happy end. Wear it well again! :)

BTW: I hope you understand that you brought this to yourself.. Starting such a topic can only bring the original poster bad luck and vengeance from the insulted watches! :p

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Nice happy end. Wear it well again! :)

BTW: I hope you understand that you brought this to yourself.. Starting such a topic can only bring the original poster bad luck and vengeance from the insulted watches! :p

I know..I know... :p

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I know..I know... :p

Let's try to break the spell completely! ;)

"Because of the historical disparity between what watch makers claim, and what watches are actually expected to be able to survive, the ISO Standard specifies a complex testing procedure for each mark. For example to receive the "Water Resistant 30M" mark, the watch must be able to survive 60 minutes under water at a depth of 10 cm (2.54 inches) followed by 10 minutes under a pressure of 3 ATM or approximately 73 PSI, with no water leakage into the case."

Well, let me just rephrase the last sentence: "10 minutes under a pressure of 3 ATM or approximately 30 meters, with no water leakage into the case" So, 30M by ISO standards is 30 meters for 10 minutes. (3ATM is the static pressure under 30 meters of sea water.)

So, according to static pressure, wearing a 30M watch, diving from a 10 meter cliff, we are ok: We are more likely to go 3-4 meters down, and stay under the surface for less than 10 seconds. Look at the Olympic divers doing so.

The key in your analysis is dynamic pressure.. Correct?

http://scienceworld.wolfram.com/physics/DynamicPressure.html

"Dynamic pressure is the component of fluid pressure that represents fluid kinetic energy (i.e., motion), while static pressure represents hydrostatic effects"

So, how can we add these two together? P total= P static + P dynamic.

Let's try calculating the dynamic part of the above mentioned dive:

P dynamic =

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Thank you..Thank you geo1nah2a :thumbsupsmileyanim:

I simply love it....remarkable that diving does not put more pressure on the watch...

I guess body mass should calculate into this also Force = Mass x Acceleration so a big guy could do more damage...and cliff diving can be very painfull....hope I am not on to something here :blink:

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The one and only RWG Limitcd cdition prototype from MsKing is now defogged and safe :1a:

I went to the lab and used the machine used to dry gels...put the temperature to 45C (heated perforated metal mesh to place a gel or in this case that watch on) and turned on the vacum pump for 15 minutes. The exessive moisture is now gone.

This is what the apartus looks like...gel dryer and small vacum pump :lol:

271812-3463.jpg

Best use for a gel dryer I've heard!!!!

What sort of work do you do? My fellowship was in Infectious Disease research and I had a long background in protein expression in Listeria and other gram positive pathogens before medical school.

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@crystalcranium

I once did premed at UofH (Houston) long time back when Akeem A was hot with the basketball but I traveled back to Norway cause i was in love with a girl there and I did not become a physician..thank god

I have a PhD in Molecular biology, I have been professor qualified and have a permanent position at my institute. I work with DNA, RNA proteins and all that cloning stuff :) The science of molecular biology is changing drastically these days as we can follow how hundreds and thousands of genes are regulated within cells simultaneously. I have also worked and work with diseases but not humans diseases. I work with science everyday and basic science is my love even if I have to do a lot of applied stuff also.

Dr. Gunnar B)

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Thank you..Thank you geo1nah2a :thumbsupsmileyanim:

I simply love it....remarkable that diving does not put more pressure on the watch...

I guess body mass should calculate into this also Force = Mass x Acceleration so a big guy could do more damage...and cliff diving can be very painfull....hope I am not on to something here :blink:

Well, the damage to the watch based on the speed of entry in the water has little to do with the weight of the guy.. If you have a WWF 150kg wrestler jump off a 10m cliff, simultaneously with a 42kg balarina, they will enter the water at the same time, with the same speed. Ok, air resistance can come into play, but it is will nt change things dramatically.

I should thank you since your post got me into reading about a subject I had neglected for years.

And since a lot of people don't share the hobby of diving off cliffs, here is an other action that is close to the same speed: punching. An average punch is around 5-10m/sec at the full extention of the hand. So, if you are wearing a watch, and punch downwards the surface of the water, you would expect to have the same results, only the turbulance of air following your fist will make it harder to compute. :) Still, don't go throwing full speed punches around a pool if your watch is unlikely to survive a 10 meter dive..unless you have a good reason that is :p

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Seams that i hve been too easy on my watches then (see post 9) will have to find a higher board ,harder water and a deaper pool, Then again i am unlikely to dive deaper than 3 m anyway, what about straping my watches tothe front of my bike and riding 100mph in a hail/thunderstorm, we have lots of that right now?

I had a poljot chrono once it did not even survive heavy rain in New orleans!

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Well, the damage to the watch based on the speed of entry in the water has little to do with the weight of the guy.. If you have a WWF 150kg wrestler jump off a 10m cliff, simultaneously with a 42kg balarina, they will enter the water at the same time, with the same speed. Ok, air resistance can come into play, but it is will nt change things dramatically.

I should thank you since your post got me into reading about a subject I had neglected for years.

I am pleased :)

Still according to my formulae Force = Mass x Acceleration the persons weight should matter quite a bit....even if the object accelerate at the same speed and thus have the same impact velocity the mass increases the force of impact the impact.........maybe I am making some mental error here?

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The mass will be of interest after the entry in the water: inertia and deceleration in fluids. But then we get too deep (pun) for my finance background :)

Ok :) I sort of picture the pressure on the watch strapped on to a well built man upon hitting the water surface as the worts possible moment for a watchs water resistance...I guees we have come as far as we can. thank you.

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