Common Misconceptions When Using Watches

(1) Wearing a watch in a sauna is a completely incorrect practice.

　　Regardless of the water resistance depth, you should never wear a watch in a sauna. While there may be no visible issues in the short term, the movement has actually been compromised. Because the external components of a watch are made of materials with different expansion coefficients, if the ambient temperature exceeds 50 degrees, a pressure difference will occur inside the watch. Under atmospheric pressure, air inside the watch will escape; when the temperature difference normalises, external air will be drawn back in. The temperature in a steam room is much higher than standard, and as the air inside escapes, it carries moisture-laden air back in. Sometimes, water vapour may not appear on the glass immediately, but when suddenly exposed to low temperatures, the warmer air inside will condense on the glass, forming water droplets or mist. Moreover, the heat of the steam will accelerate the ageing of the waterproof seals, preventing them from properly protecting the movement.

(2) Using water droplet condensation to confirm if the crystal is sapphire;

　　This is an unscientific method because some mineral glasses can also cause water droplets to bead, while water droplets on some sapphire crystals may spread. However, the scratch resistance is the same. The manufacturer will specify the material of the crystal; do not use water droplets to test it.

(3) Quartz watches lose their water resistance and accuracy after a battery change: This view is incorrect.

　　Professional repair facilities are well-equipped. After changing your battery, professional technicians will use specialised instruments to re-pressurise, reset the water resistance, and measure whether the timekeeping error is within the normal range. Therefore, please ensure you have the battery changed at a professional service centre.

(4) Using methods like rubbing against the ground or scratching glass to prove a watch's scratch resistance is not recommended, as we advise customers against using destructive behaviour to test it.

　　Additionally, while high-tech ceramic is highly scratch-resistant, it is brittle and susceptible to damage from drops and violent impacts.