What should the maximum daily variation of my mechanical watch be?
The daily variation in timekeeping of a mechanical watch is dependent on several fundamental points, such as the quality of the watch movement, how much, and where the watch is mainly worn, or the influence of extreme fluctuations in temperature. However, as a rule a watch that is technically correct may still gain up to 10 seconds per day.

What is a chronometer?
A chronometer is a certified watch. The variation of the timekeeping by the watch movement is tested for 14 days in a variety of locations at 4°, 20°, and 36°. Should it fulfil the toughest of criteria, the numbered watch movement receives the official label of chronometer".

What is a chronograph?
A chronograph is a watch with an additional function that measures units of time.
 
 

Can sapphire glass also be scratched?
Yes, sapphire glass can also be scratched. Sapphire is rated as 9 on the scale of hardness. Rated at 10, only diamonds are harder. Sapphire glass can thus be scratched by a diamond or by a similarly hard material. The building material concrete contains corundum, which is also classified as 9 on the hardness scale.


How long is my watch water resistant for?
A watch is classified as water resistant when fine seals on the glass, crown, and back protect the watch movement from moisture (water). The seals should be replaced every 2 years. The elasticity (depending on the thickness of the seal) wears off after 2 years and can no longer protect the watch from moisture (water).