.Technical Library

Frequent Asked Questions | Glossary


A watch that alerts you with beeps at pre-set time(s).


A watch that has hour, minute and second hands.


Automatic (self-winding)
A watch with a mechanical movement that winds by the motion of the wearer’s arm rather than through winding the crown. A rotor will wind the mainspring in response to the hand motion. An automatic watch have to be worn every day. After 2 days or so, it may stop and require winding (by rocking the watch in a to-and-fro motion) for a few minutes to get the watch working again.


Atmospheric pressure is used as a measure of water resistance. 1 ATM = 10m = 33 ft.


Battery (or cell) reserve indicator (also known as end of battery indicator)
A feature found on some battery-operated watches that indicates when the battery is approaching end of its life. This is often indicated by the second hand moving in 5-second intervals instead of every second.


A ring that surrounds the watch dial usually made of gold, gold plate or stainless steel.


Bi-directional rotating bezel
Bezel that can be rotated clockwise or anticlockwise direction.


Butterfly clasp
A hidden bracelet closure for continuous design.


A feature that shows the date, and often the day of week.


Refers to movement type, eg automotive or quartz.


The housing for the movement, dial and crystal.


An analog movement with a stopwatch function. There are many variations on the chronograph. Some have seconds hand in centre of the watch’s face that keeps time. Others use sub-dials to record seconds, 30-minute and 12-hour timing.


Chronograph alarm
A watch that has both a stopwatch and alarm function.


Refers only to mechanical watches that has obtained an official rate certificate from the COSC (official Swiss Chronometer Testing Institute), after having passed stringent precision tests over a 2-week period.


Countdown Timer
A function that beeps after a pre-set period of time.


The “knob” used to set the time and/or date functions. A screw-in crown is used to increase the water tightness of the watch, making it more water resistant.


The transparent cover on a watch face made of glass, synthetic sapphire or plastic. Some watches have a sapphire crystal which is resistant to scratching.


Depth alarm
Feature found in professional diving watches which has an alarm that sounds when the wearer exceeds a certain pre-set depth.


Depth sensor or depth meter 
A device on a diver’s watch that shows the depth either by analog hands and a scale on the watch face, or through a digital display indicating the depth achieved by measurement of surrounding water pressure.


The “face” of the watch.


A watch that shows the time in electronic digits rather than with a dial and hands (analog).


Diving watch
A watch that is water resistant to 100M or more. It has a one-way rotating bezel and a screw-on crown and back.


Flyback hand
A function that allows the chronograph to be reset to zero without having to stop the chronograph. This is useful for timing multiple lap times or finishing times, since the stopping, resetting and re-starting leads to a short delay at the beginning of timing for the next leg.


Abbreviation for Greenwich Mean Time.


A layer of gold electroplated to the base metal.


Kinetic (also known as Automated Generated System, AGS)
The technology that uses a quartz movement that does not use require a battery. A capacitor, which powers the quartz movement, is charged by wrist movements. If the watch is worn every day, the capacitor is continually recharged. The capacitor will need to be changed to maintain power storage capacity after 3 years or so.


Refer to lighting on a watch dial that allows the wearer to read the time in the dark.


Found in mechanical watches, where synthetic sapphires or rubies are used as bearings for pivots in watches. The jewels reduce friction to make the watch more accurate and longer lasting.


Lap memory
Usually found in digital watches, that has a chronograph function to let the wearer time different laps of a race. Different laps of a race can be recorded simultaneously without need to reset chronograph timing.


Mechanical movement
A movement powered by a mainspring, working in conjunction with a balance wheel.


Measurement of metal plating for durability. 


The inner mechanism of a watch that are either mechanical or quartz.


Sub-dial measuring seconds.


Moon face (AM/PM)
Rotating moon display showing the sun (AM) and the moon (PM).


Power reserve indicator
A feature in a watch that indicates the power reserve in the watch before it will stop. For quartz watches, this is often indicated by the seconds hand moving at 5 seconds’ intervals, whereas mechanical watches would have a separate indicator on a sub-dial.

Quartz movement
Battery operated mechanism, eliminating need to wind daily; analog watches only.


Rotating bezel
A graduated rotating bezel that can be turned so that the wearer can align the zero on the bezel with the watch’s seconds or minutes hand. The time duration can then be read off the bezel. Different types of rotating bezels perform different timekeeping and mathematical functions.


It is a flat piece of metal shaped like a semicircle found in an automatic (or self-winding) mechanical watch. It swivels on an axle with the motion of the wearer’s arm and winds the movement’s mainspring.


Sapphire crystal
A crystal made of synthetic sapphire which is scratch-resistant.


Screw-lock crown
A crown that can be screwed into the case to make the watch water-tight. To set the time, unscrew the crown, and then pull the crown to set the time. After time adjustment, push the crown in and turn at the same time until it is screwed tightly into place. If it is not screwed in, it is not water resistant.


Two time zone indicator
A watch with an additional dial that can be set to another time zone.


Solar powered
A watch that uses solar energy to power the quartz movement.

A stopwatch function that is incorporated into a quartz or mechanical watch to measure intervals of time.


Small dials on the watch’s face used for several purposes, such as keeping track of elapsed minutes or hours on a chronograph or indicating the date.


A tachymeter is an instrument for measuring speed. It is a chronograph with a graduated dial on which speed can be read-off in kilometers per hours based on 1000m distance.


A metal that is hypoallergenic and used for some watch cases and bracelets. It is much stronger and lighter than stainless steel, but more expensive.


Unidirectional rotating bezel
A unidirectional bezel only turns one way to prevent a diver from accidentally moving its bezel off its original position and overestimating his remaining air supply as a result. Since the bezel only moves in only one direction, it will simply indicate the diver has less air or decompression rather than more.


Water resistance
Water resistant markings are indicated on the watch, often on the back of case.



Example of use

Water resistant

Withstand splashes of water or rain; do not submerge

3 atm/ 30m/ 100ft

Withstand splashes of water or rain; do not submerge

5 atm/ 50m/ 165ft

Rain, showering, swimming

10atm/ 100m/ 330ft

Rain, showering, swimming, sailing, snorkeling, recreational diving

20atm/ 200m/ 660ft

Rain, showering, swimming, sailing, snorkeling, recreational diving, surfing, white water rafting


Watches will withstand water resistance as long as the crystal, crown, case, push buttons and gaskets remain intact.

Important note: Do not operate crown or buttons when watch is wet or submerged.


World Time
Watch that shows the current time in the major cities around the world.


World time dial
The time zones are represented by the names of cities printed on the bezel or dial, typically on the outer edge of the watch face. It that tells the time for the different zones based on GMT.




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