A
A/H
Amplitude Amplitude (semi oscillation) of the balance is the change between peak (highest amplitude value) and trough (lowest amplitude value) within a one-hour period
Automatic Winding
In a watch that requires automatic winding, the centrifugal and gravitational forces are used as an energy source. A semicircular weight called the rotor or balance weight winds the spring through the arm movements of the person wearing the watch. As an automatic watch is continuously being wound, the tension spring has a sliding clutch instead of an end hook. When the watch has been wound completely, the spring descends, and overstraining is circumvented. For more information about Automatic Watches please see our essential guide
B
Beyond Steel Beyond Steel® from Davosa has truly outstanding properties. With a hardness comparable to a diamond, it is corrosion and heat resistant, rust and nickel-free, and is practically indestructible. Beyond Steel® can be considered a material in a super class of its own and Davosa has harnessed the outstanding, high-performance properties to create the optimal bezel inlay for watches such as the new Davosa Argonautic BGBS. For more information about watches that offer this feature
Click to view our useful guide to watch bezel types
Bronze
Bronze is a copper alloy that reacts when it is exposed to oxygen allowing a natural patina to form (oxidization). Natural oxidization of the bronze will gently provide varying degrees of coloration in brown, red, black, blue, or green hues that will give each Davosa bronze watch its own unique and distinguishing character. Oxidation of bronze is a natural process and not a quality defect. To keep the oxidation of the bronze components of a DAVOSA watch to a minimum before it is worn by the buyer, the watch is delivered in a vacuum-sealed protective cover. We recommend keeping the watch in this cover before wearing it. When the watch has been unpacked, the bronze parts should not touch the skin, to avoid locally increased discoloration of the surface. Bronze watches should be stored cool, dry, and protected from light. Cleaning a DAVOSA bronze watch: We recommend not to remove the patina. It acts as a natural protective layer for the bronze. You can carefully clean the bronze parts, to remove unsightly marks: We recommend mixing salt with a little vinegar and rub in with a soft brush, then rinse with water.
C
High-Tech Ceramic
Both decorative and functional, bezel inlays can be made from a variety of materials but are mostly made of a high-tech ceramic that is extremely scratch-resistant with a hardness of 1250 HV (Vickers). Both heat and corrosion-resistant, the colored bezels possess a smooth finish thanks to a high-gloss polish. An elaborate and expertly created production process ensures that each bezel is of a consistent high quality and possesses exceptional color brilliance. For more information about watches that offer this feature
Click to view our useful guide to watch bezel types
Chronograph or Chrono
A Chronograph or Chrono watch tells the time and is also equipped with a timer mechanism or stopwatch. A chrono can be easily recognized by the extra push buttons, which release, stop, and reset the chronograph hand. This hand turns once a minute, like a second hand on an auxiliary watch face. Further small hands count the minutes, half hours, hours and even tenth of seconds respectively. For more information about watches that offer this feature
G
GMT
The GMT function for wristwatches was originally developed in the 1950s for pilots whose job regularly took them back and forth between different time zones. The acronym GMT refers to Greenwich Mean Time: the official ‘world time’ until 1928. Today it has been replaced by UTC or Coordinated Universal Time, however most watchmakers still use the older terminology when referring to watches with a second time zone. How do GMT watches work? Click to view our dual time watch guide & Click to view our GMT Watch Guide
H
Helium Escape Valve
The helium valve was specifically developed for professional divers, who can work underwater for extended periods of time. During their breaks they rest in diving bells which are filled with a mixture of helium and oxygen. The helium molecules are so small that with extremely long dwell times and under high pressure, they can penetrate the watch case through the watch seals. So, there is a balance of helium molecules in the decoration chamber and in the watch case. During decompression an overpressure is created in the watch case. Helium molecules cannot escape from the watch case as quickly as, for example, from the body/tissue of a diver. The helium valve allows the excess pressure to escape from the watch case without the watch glass being blown off. Click here for more information about watches that offer this feature
K
K1 Mineral Glass 1 Mineral Glass is a super-hardened glass that is created by an innovative grinding process. Crystal clear, K1 Glass is scratch and impact resistant, and is known for its strength and superb clarity, making it the ultimate glass for watch faces used by watchmakers. According to the Vicker Hardness Test, Sapphire has a hardness of around 1900, K1 around 700 and Mineral Glass around 380. For the Mohs Hardness Scale (from 0-10, the hardness of a diamond is 10): sapphire is around 9, K1 is around 6 and mineral glass is around 4. Click to view our Watch Crystal Guide
M
Moonphase Adjustment The moonphase feature on a watch is designed to display the 29.5-day lunar cycle. However, in practice, this is complicated since the moon does not follow an exact 24-hour rhythm. In order to adjust the moonphase function pull out the crown to position 2 as explained in the instructions provided. You can then move the moon around in a clockwise direction. The simplest way to set the moonphase dial is to wait until there is a full moon and then set the full moon icon at the top of the dial. However, if you would like to set the moon in its exact phase immediately it is necessary to research the current phase of the moon either online or by an almanac. Remember it will take almost a month for the Moonphase dial to rotate. Click to view our moonphase watch guide
Mother of Pearl
Iridescence is an optical phenomenon that gives Mother of Pearl its characteristic shine and produces a rainbow of different colors depending on how light hits it. The insides of certain seashells are made up of multiple thin layers of material, which are responsible for creating this shimmering effect. Incidentally, pearls are created in a similar process. The thin overlying layers break and reflect light differently, resulting in a color spectrum that you can also find in a rainbow.
P
PVD Plating PVD stands for physical vapor deposition and offers the ultimate in robust and long-lasting color and composition. In the PVD process the watch case or strap is placed in a sealed, pressurized chamber where the material is vaporized, creating a saturated atmosphere. The basic substrate stainless steel becomes completely saturated by vaporized molecules, creating an even and deep deposition of color. In contrast to traditional plating or lacquering techniques, which only coat the surface of the substrate, making it subject to abrasion and tarnishing through exposure to UV rays or moisture, a PVD coating does not discolor thanks to the complete penetration of the color particles into the metal, allowing for a flawless finish. Click to view watches that offer this feature
S
Superluminova
SuperLumiNova luminescent pigments are the latest patented development in the field of non-radioactive luminescent pigments. Thanks to their highly improved light storage capacity, these pigments can be used as luminescent markers on watch hands and dials. In essence, the photoluminescent pigments work like a light battery. After sufficient charging with either sunlight or artificial light, the stored light energy is discharged in the dark over a long period of time. This charging and discharging process can be repeated indefinitely and does not deteriorate or weaken over time. Click to view our watch lume guide
T
Tachymeter
The tachymeter scale on the watch face of a chronograph is used to measure the speed, e.g., of a car over a 1-km (0.62 miles) distance. The chronograph is activated when the vehicle passes the starting point and deactivated when the vehicle has reached the final point. The figure shown on the tachymeter scale corresponds to the speed in km per hour. The speed must be equal over the whole test distance. Click to view our essential racing watch guide
Telemeter
A telemeter scale enables the calculation of the distance between an acoustic signal and its own position. Or, put more simply, it can be used to determine the proximity of a storm. To do this, the chronograph is started when lightning strikes and stopped at the first clap of thunder. It is then possible to gauge how far away the storm is by reading the telemeter scale and using the second hand as a counter. The scale is based on the well-known sonic speed value (343 m/s or 1,235 km/h - 1,126 ft/s or 768 mph) and was originally employed in a military context. It was used to determine the enemy's position via muzzle flashes and cannon fire.
Tritium Gaseous Tubes
Tritium is a colorless gas and is the only naturally occurring radioisotope of hydrogen. The name Tritium originates from the Greek word meanign 'tritos' and refers to the three components of the atom (3H). ‘Tritium has been used for decades in a variety of applications where constant, independent, and long-lasting light sources are essential. On the dials of military watches, you will often find a red, circular symbol with the notation ‘3H’ that refers to the use of tritium. In ‘civil’ watches, the abbreviation ‘T25’ denotes the same thing. In the past, luminous tritium was applied directly to the dial. Today’s watchmakers are more careful and fill the gas into fine tubes made from borosilicate glass, a highly resilient and ISO-certified glass used in chemical engineering. These Gaseous Tritium Light Sources (or GTLS) are not only exceptionally safe, but they also guarantee the watch wearer at least ten years’ constant luminance – without any external energy source. For more information about watches that offer this feature
W
Water Resistance
Wristwatches that are resistant to water penetration up to the specified depth are referred to as "water resistant". "Water protected" means that the watch is resistant to splashing water or everyday (hand) washing only. The DIN standard 8310 regulates whether a watch is considered "water resistant" or not. The criteria are typographic tests. If a watch can withstand a pressure of 200 meters deep, this means to 20 bar or 20 ATM. The watch can be classified as a diver's watch, and you can dive with it safely. Watches with 10 ATM, however, should be used only for swimming and snorkeling, while watches with 5 ATM are only considered "water-protected", whereby they are protected against splashing water and can be worn while bathing. If a clock is only awarded 3 ATM, it should be limited to splashing water only. To view our essential guide about water resistance: Click to view our Essential Diving Watch Guide
