First, the watch water into the watch what harm?
1. It is well known that quartz watches and electronic watches are composed of components such as resistors, capacitors and batteries. Water itself is an excellent conductor of electrons, and electrons will “flow” in water (liquid). Once the amount of water is too large, it will cause short-term burning. The substrate of a bad quartz movement may not have problems in the short term if the amount of water is low, but over time, water (liquid) will corrode the circuit board and cause permanent damage to the movement. Water in the mechanical watch will cause the oxidation of the flywheel gear movement and other components, resulting in degraded accuracy. Even large deviations in timing may render the mechanical watch unusable.
2, temperature difference is too large, such as long-term out of the high temperature or steam room, the long will make watch parts variants and watch water (here refers to why the watch is not hot water and water vapor problems will be mentioned below), resistance container Change the electrical properties. As a result, the watch stops or the accuracy decreases.
It can be concluded from the above that no matter how sophisticated the craftsmanship of the watch and the strong waterproof standards, do not try to take a bath (other than a cold shower) or a sauna.
PS: Next, introduce the waterproof standard.
Second, watch waterproof standard:
30 meters: daily life waterproof, waterproof splash. You can wash your hands and face.
50 meters: The water-repellency of everyday life can be washed with a small amount of cold water, and it cannot be soaked in water.
100 meters: submerged floating standard, can be used in the pool or seawater surface.
200 meters or more: The diving watch can be used in the depth of the underwater breathing apparatus (The waterproof standard of the watch should be selected according to the diving depth)
Third, waterproof watch rating and waterproof logo
In the watch factory, the waterproof function of the watch is mainly realized through the waterproof rubber ring of the crown, the table mirror, the back cover, etc. Some special high-end watches will use the spiral crown to achieve the corresponding waterproof standard. The waterproof performance of the watch is usually classified according to its rating: non-waterproof (without label on the back of the watch), anti-sweat (SWEAT-RESISTANT), general waterproof (WATER-RESISTANT), 30m waterproof (30M, 3ATM, 3BAR), 50 Meter waterproof (50M, 5ATM, 5BAR), diving watch 100 meters waterproof, 200 meters waterproof, 300 meters waterproof and so on.

Fourth, the watch's international water standards
Regarding the waterproof performance of the watch, the national standard and the international standard all have the clear stipulation: Any watch that indicates the waterproofing, must endure 2 atmospheric pressures at least, namely does not enter the water in the water depth of 20 meters. 30 meters waterproof means that the watch can tolerate 3 atmospheres, and so on. The premise of this standard is that when the test is conducted, it is under laboratory conditions: the temperature is maintained at 20-25 degrees Celsius, and both the watch and the water are at rest. In this case, the watch is qualified if it is waterproof.
Some watchmates believe that "my" watches can reach 100 meters or even 300 meters of water, and they wear their own love watch to bathe in the sauna. In fact, this approach is completely wrong, because the watch itself is not an absolute sealed shell, which means waterproof is not necessarily waterproof vapor, we all know that water vapor is mixed in the air, the reason why it can float in the air is Because the molecular structure of water vapor is very small. The seal of the watch is based on the gap between the bottom cover and the watchcase. If the temperature difference changes, the atmospheric pressure will squeeze air with a large amount of moisture into the watch, and the water will also age the rubber. Loss of performance and loss of waterproof function.