A sapphire glass is a watch crystal that is made of a piece of artificial sapphire. Having a hardness of 9 mohs, it is extremely hard and scratch resistant and can only be scratched by a diamond.
A watch with the description of «30 m» or «3 bar» has been tested for water resistance at three bar. Three bar is equivalent to a pressure of 3kg/cm2. In principle, when engaging in a water sport or swimming, a normal water resistant watch (three bar) should not be worn because the movements of swimming can easily take the pressure higher than three bar.
Gold plated is a layer of a gold alloy which is combined insolubly to the basic metal (steel, brass, nickel silver). The thickness of the layer is given in microns.
An abbreviation which stands for Physical Vapour Deposition. The PVD technology used for watch cases and bracelets is one of the most up-to-date and non-polluting coating systems. Its quality can be compared to 10 micron gold plating. The PVD finish is highly scratchproof and long lasting. The primary desirable qualities of PVD coatings are hardness, durability and anti-allergenic properties. An enhanced process allows the deposition of extremely hard and smooth diamond like carbon (DLC) film.
The Helium valve is intended for divers staying in a pressure chamber or diving station for several days. In these places the air is enriched with helium to aid breathing. The tiny helium molecules are capable of penetrating through the watch joints. Unfortunately, the helium does not escape in the same way. Therefore, the helium valve can be opened to enable the excess pressure to escape. The valve must not be opened in the water. Helium is a noble gas and not harmful to health.
The DLC (diamond-like carbon) coating process is a PVD (see FAQ topic) coating process using diamond like carbons. This durable and friction-reducing coating with an anthracite-coloured appearance essentially comprises diamonds measuring just a few nanometres across, coated in graphite. This structure is commonly referred to as Diamond-Like Carbon (DLC). Thanks to its diamond-like layered structure, DLC layers possess exceptionally hard surface properties. They are substantially harder and more durable than ultra-hardened grades of steel, and are exceptionally corrosion-resistant, as well as being skin-friendly. DLC coatings are harder than classic PVDs and therefore have an increased resistance to abrasion.
A chronograph is a watch with hands that display hours, minutes and seconds, together with a mechanism for measuring elapsed time by means of a central chronograph hand, which records seconds, and totalisers for the minutes and hours (not mandatory). A chronometer is a watch whose movement has obtained an official rate certificate from the COSC (Official Swiss Chronometer Testing Institute) after having passed precision tests in different positions and at different temperatures. These tests are conducted over a 15-day period.
The push buttons serve to start or stop the function, and to reset the chronograph. Generally, the push button at 2 o'clock is to start and stop the chronograph function.
The functioning of a self-winding mechanical movement depends on the wrist movements of the wearer. When fully wound, the watch will have a power reserve between we specify in the description measured in hours. Since the watch's self-winding mechanism is directly linked to the wearer's activity, generally 8 to 10 hours ensures that the watch will continue to run throughout the night. However, if a watch has not been worn for several days and its power reserve has thus run low, we recommend you wind the watch manually for around 15 rotations of the crown (clockwise) to ensure the best possible rate from the outset.
Like any high-precision instrument, a watch needs to be services regularly in order for it to work perfectly. While, we cannot indicate the intervals, given that it depends entirely on the model, climate and the care taken by the watch's owner. As a general rule, it is between 4 and 5 years, depending on the use of the watch.