The American Watchmakers Institute has an article from a watchmaker in New Zealand and he wrote the following about “waterproof and watches today”:
The basic figures for the water resistance ratings of watches are derived from ISO (International Standards Organization) 2281 document
Most watches will have some form of water resistance rating printed on the dial (the watch face) or on the back of the case. Usually in the form of “Water Resistant X meters” where X is usually 30,50,100,150 or 200. Additionally the word “Divers” may be seen-this represents a higher level of water resistance which requires different tests as outlined in the ISO specification for Divers grade watches. Where no rating is given it is assumed that the watch is NOT suitable for immersion in water and no guarantee should be given as to the water resistance of the watch. Unless specified as a “Divers” grade watch, the watch should not be used as such.
With regards to the phrase “Water Proof” -This is an outdated expression which is no longer in use in the industry as it implies that a watch is completely impervious to any form of leakage regardless of conditions, this is not the case, as given extreme enough conditions (e.g. extreme ocean depths) there is virtually no way of making what is essentially a container such as a watch case completely watertight. The expression “Water resistant” is now used instead which can be taken to mean that it only resists water and given appropriate conditions this resistance may be overcome and the watch may leak.
The words “Water Resistant” and the “depth” rating do not directly rate to each other. To be eligible to be certified as “Water resistant” a watch must pass a combination of 5 of 6 tests. These test are as follows:
- Resistance to air over pressure- A watch should not leak when subjected to a pressure of 2 bar at a rate of more than 50 micrograms of air per minute when put into a pressurized dry chamber.
- Condensation Test- The watch is heated to a temperature of 104-113 Fahrenheit, then a drop of water of 65-77 degrees Fahrenheit is placed on the glass. After approximately 1 minute no condensation should have formed on the inside of the watch glass.
- Resistance when immersed in water at a depth of 3.9″ -The watch should show no signs of leakage when left in 10cm of water for 1 hour.
- The watch should not leak when a force of 5 Newtons is applied to the crown or other operating buttons at an angle perpendicular to the casing while the watch is immersed in 3.9″ of water for 5 minutes.
- At a depth of 3.9″ in water the watch should be heated successively to 104 Fahrenheit for 5 minutes, then 68 Fahrenheit for 5 minutes, and then again to 104 Fahrenheit for 5 minutes. The watch should show no signs of leakage at any stage during the test.
What to know about your Self-winding watch.
We hope you find the following information about your timepiece informative and that it will better assist you in the proper functioning of your watch.
You may experience that your self-winding watch occasionally stops overnight or appears to be running slowly. This does not necessarily indicate a malfunction or defect in the watch. In most cases, the problem is related to the power reserve that has not been properly initiated or, may be the result of too insufficient wrist action while wearing the watch.
For a self-winding watch to function properly, the mainspring must build up a sufficient power reserve. Many people are unaware that a self-winding watch needs to be wound first manually before it will run automatically. This is called the initiation process. Without the initiation process, the watch will never operate properly or consistently. To initiate the power reserve, the watch must be wound manually. Turn the winding crown at the 3 o’clock position, in a clockwise direction for about 40 revolutions. This start up wind is usually sufficient for most automatic watches.
After completion of the initiation process, the watch will wind itself automatically [rebuilding the power reserve) by means of an oscillation weight that shifts every time the watch’s position is changed by the action of the arm and wrist.
A self-winding watch should be worn at least eight hours a day to maximize the power reserve. If this is not possible, or if the watch has been off the wrist for more than 15-20 hours, the initiation process must be repeated.
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