Watch Terms

A

A.H.P.: Automatic High Precision. A swinging rotor drives a mini-generator. Its electric power is stored in a capacitor, which supplies energy to the quartz-controlled integrated circuit.

A.S.S. : Servo-controlled motor drive. The system, integrated in the circuit, lengthens the duration of motor impulse when the mechanism meets resistance (during date-change for example) and reverts to the normal duration when the resistance ends. The technique increases battery life by 30%

Alarm: A device that sounds a signal at a pre-set time.
Altimeter: A device that determines altitude by responding to changes in barometric pressure.

Anadigi Display: A display that shows the time both by means of hour and minute hands (an analog display) and by numbers (a digital display)

Analog Display: A display that shows the time by means of hands and a dial.

Analog quartz: The most commonly-used term in referring to any analog timepiece that operates on a battery or on solar power and is regulated by a quartz crystal.

Analog Watch: A watch with a dial, hands, and numbers or markers that present a total display of 12-hour time span. Analog digital refers to a watch that has both a digital display and hands of a conventional watch.

Aperture: Small opening. The dials of some watches (in French: montres à guichet) have apertures in which certain indications are given (e.g. the date, the hour, etc).

Assembling: Process of fitting together the components of a movement. This was formerly done entirely by hand, but the operations have now been largely automated. Nevertheless, the human element is still primordial, especially for inspection and testing.
Atmosphere (Atm): Unit of pressure used in watch making to indicate water-resistance.

Atomic time standard: Provided by the U.S. National Institute of Standards and Technology, Time and Frequency Division, Boulder, Colorado, atomic time is measured through vibrations of atoms in a metal isotope that resembles mercury. The result is extremely accurate time that can be measured on instruments. Radio waves transmit this exact time throughout North America and some "atomic" watches can receive them and correct to the exact time. To synchronize your watch with atomic standard time, call (303) 499-7111.

Automatic Movement: A mechanical movement that requires no winding because the rotor, part of the automatic mechanism, winds the mainspring every time you move your hand. The first automatic movement was invented in Switzerland by Abraham-Louis Perrelet in the Eighteenth century. When fully wound and left to sit, most automatics have up to 36 hours of reserve power. Mechanical movements are accurate within one minute each day. Automatic movements have gained in popularity the last few years especially with watch connoisseurs and are considered to be Switzerland's mechanical answer to the popularity of the no-winding-needed quartz movements that are standard in Japanese watches.

Auto Repeat Countdown Timer: A countdown timer that resets itself as soon as the preset time has elapsed and starts the countdown again. It repeats the countdown continuously until the wearer pushes the stop button.

Automatic Watch: A watch whose mainspring is wound by the movements or accelerations of the wearer's arm. On the basis of the principle of terrestrial attraction, a rotor turns and transmits its energy to the spring by means of an appropriate mechanism. The system was invented in Switzerland by Abraham-Louis Perrelet in the 18th century.

Automatic Winding: (also called "self-winding") Winding that occurs through the motion of the wearer's arm rather than through turning the winding stem. It works by means of a rotor that turns in response to motion, thereby winding up the watch's mainspring. An automatic watch that is not worn for a day or two will wind down and need to be wound by hand to get it started again.

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B

Baguette: Ladies style watch with a thin, elongated faces; usually rectangular in shape but may be oval.

Balance Spring: A very fine spring (also called a "hair spring") in a mechanical watch that returns the balance wheel back to a neutral position.

Balance Wheel: The part of a mechanical watch movement that oscillates, dividing time into equal segments. Lengthening or shortening the balance-spring makes the balance-wheel go faster or slower to advance or retard the watch.

Barrel: Thin cylindrical box containing the mainspring of a watch. The toothed rim of the barrel drives the train.
Bar/lug: A small rod with a sprung pivot at either end to fix the strap (band) to the case.

Base metal: Any non-precious metal.

Battery: Device that converts chemical energy into electricity. Most watch batteries are silver oxide type delivering 1.5 volts. Much longer-lasting lithium batteries are 3 volt.

Battery Life: The minimum period of time that a battery will continue to provide power to run the watch. Life begins at the point of manufacture when the factory initially installs the battery
Battery Reserve Indicator: See "power reserve indicator".

Bezel: The surface ring on the watch, usually made of gold, gold plate or steel, that surrounds the crystal in place. A rotating ratchet bezel moves in some sport watches as part of the timing device. If rotating bezels are bi-directional, able to move clockwise or counter clockwise, they can assist in calculations for elapsed times.

Bi-directional Rotating Bezel: A bezel that can be moved either clockwise or counterclockwise. These are used for mathematical calculations or for keeping track of elapsed time.
Bracelet: Flexible metal band consisting of assembled links, usually in the same style as the case. Detachable links change the length of the bracelet.

Brass: Copper and zinc alloy used to make the main plate and bridge wheels in the movement.

Buckle: Usually matching the case, it attaches the two parts of the leather strap around the wrist.

Button: Push piece controls, usually at 2 o'clock and/or 4 o'clock on the dial to control special functions such as the chronograph or the alarm.

Bridge: Complementary part fixed to the main plate to form the frame of a watch movement. The other parts are mounted inside the frame.

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C

Cabochon: Decorative stone which has been carved into a round shape.

Cabochon crown: A rounded semi-precious stone or synthetic material usually black, fitted into the watch crown as an ornament.

Calendar: A feature that shows the day of the month, and often the day of the week and the year. There are several types of calendar watches. It can be displayed through a cut-out window in the dial, as a sud-dial with small hands indicating the day/date feature or by digital readout.

Caliber: A term often used by Swiss watchmakers to denote a particular model type, such as Caliber 48 meaning model 48. More commonly, the term is used to indicate the movement's shape, layout, or size.

Cambered: Often used in referring to a curved or arched dial or bezel.
Carat (Karat): Unit of gold fineness (and gemstone weight). Pure gold is 24k. 18k gold is 75% pure.

Case: The metal housing of a watch's parts. Stainless steel is the most typical metal used but titanium, gold, silver, and platinum can also be used. Less expensive watches are usually made of brass and plated with gold or silver.

Case back: The reverse side of a watch case that lies against the skin. May be transparent to allow viewing of the inner workings of the watch or be solid. Most manufacturers engrave case backs with their name, water and shock resistance, case metal content and other details.

Chime: The bell-like sound made when a clock strikes on the hour, half hour, etc. Two familiar chimes traditionally found in clocks are the Westminster chime made by the famous Big Ben in London, and the bim bam, a two note chime.

Chronograph: A stopwatch, i.e., a timer that can be started and stopped to time an event. There are many variations on the chronograph. Some operate with a center seconds hand which keeps time on the watch's main dial. Others use sub dials to elapsed hours, minutes and seconds. Still others show elapsed time on a digital display on the watch face. When a chronograph is used in conjunction with specialized scales on the watch face, it can perform many different functions, such as determining speed or distance. Some chronographs can time more than one event at a time. Do not confuse the term "chronograph" with "chronometer". The latter refers to a timepiece, which may or may not have a chronograph function that has met certain high standards of accuracy set by an official watch institute in Switzerland. Watches that include the chronograph function are themselves called "chronographs".

Chronometer: This term refers to a precision watch that is tested in various temperatures and positions, thus meeting the accuracy standards set by an official institute in Switzerland. Most watch companies provide a certificate with your chronometer purchase.

Clasp: The attachment used to connect the two ends of the watch bracelet or strap around the wrist.

Deployment Buckle—a three-folding enclosure, which secures the two ends of the bracelet and allows enough room for placing the watch on the wrist when fully deployed. When closed, the buckle covers the two-piece folding mechanism

Fold-Over Buckle—See Deployment buckle

Hook Lock—two separate units each fitting on either end of the bracelet which allows the watch to be laid out. One end of the closure hooks onto the other to secure the two ends of the bracelet.

Jeweler's Clasp—a closure that is generally used on better bracelets. Also allows it to lie flat.

Sliding Clasp—also a hook type method but allows for easy sizing of the bracelet by sliding up.

Twist Lock—a closure similar to Jeweler's Clasp used on ladies jewelry bracelets.

Complication -a watch with other functions besides time keeping. For example, a chronograph is a watch complication. Other complications coveted by watch collectors include: minute repeater, tourbillion, perpetual calendar, or split second chronograph.
Complication: A watch with other functions besides timekeeping. For example, a chronograph is a watch complication. Other complications coveted by watch collectors include: minute repeater, tourbillon, perpetual calendar, or split second chronograph.

Corrector: System to set the watch indicators (the hour, minute or day) by means of the crown

COSC: The official Swiss Chronometer Testing Institute that puts every chronometer watch through a rigorous, 15-day testing procedure to verify the watch's precision.

Countdown Timer: A function that lets the wearer keep track of how much of a pre-set period of time has elapsed. Some countdown timers sound a warning signal a few seconds before time runs out -- these are useful in events such as yacht races, where the sailor must maneuver the boat into position before the start of a race.

Crown: Button on the outside of the case that is used to set the time and the calendar, and, in the mechanical watches, to wind the mainspring. A nodule extending from the case that is used to set the time, date, etc. Most pull out to set the time. In water resistant styles, the crowns should screw down.

Crystal: The transparent cover on the watch face made of glass crystal, synthetic sapphire or plastic. The clean cover over the watch face. Three types of crystals are commonly found in watches. Acrylic crystal, a plastic, is inexpensive and shallow scratches can be buffed out. Mineral crystal is comprised of several elements that are heat treated to create unusual hardness that aids in resisting scratches. Sapphire crystal is the most expensive and durable, approximately three times harder than mineral crystals and 20 times harder than acrylic crystals. A non reflective coating on some sport styles prevents glare.

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D

Day/Date Watch: A watch that indicates not only the date but also the day of the week.

Day/Night Indicator: A colored or shaded band on a world time that shows which time zones are in daylight and which in darkness.

Deployment Buckle: A type of buckle that pops open and fastens using hinged, often adjustable, extenders. Though more expensive than a belt-buckle like closure, a deployment buckle is easier to put on and remove and is more comfortable on the wrist.

Depth Alarm: An alarm on a diver's watch that sounds when the wearer exceeds a pre-set depth. In most watches it stops sounding when the diver ascends above that depth.

Dial: The watch face. In high-end watches the numerals, indices and surface designs are applied as separate elements. In less expensive watches, they may be simply printed on the dial.

Diachronic: A liquid-crystal display (LCD) enabling a color to appear or vanish on the surface.

Digital: Any watch that shows the time in numbers instead of hands on the dial. The numbers appear in LCD (liquid crystal diode) which shows a continuous reading or in LED (light-emitting diode) which shows time at the push of a button.

Digital watch: A watch that shows the time through digits rather than through a dial and hands display.

Directional compass: Can be displayed by rotating a bezel or digital readout on the face of the watch. It is used to determine a geographical direction using the location of the sun.

Direct-drive: A function that allows the second-hand to advance in intervals rather than a smooth sweep for more precise timekeeping. The French term for a direct-drive second hand is a trotteuse.

Divers Watches: Diver's watches are designed and manufactured especially for divers whose lives depend on the reliability of their watch in the water.

Seiko and Pulsar diver's watches meet ISO (International Standardization Organization) regulations. Diver’s watches must meet various standards regarding water resistance, pressure resistance, readability in the water, time presetting function (rotating elapsed time bezel), anti-magnetic ability, anti-shock, rust resistance in salt water, manageability in water, ability to withstand sudden temperature changes, etc.

Seiko and Pulsar diver's watches also have features such as:
Rotating Bezel will only rotate counter clockwise. This is so in case rotated accidentally the bezel will not show an extended diving duration.

For accurate setting, bezel also has a one minute interval click.
Inscribed on the case back is the battery replacement month to prevent the watch from stopping during a dive.

Straps feature extra large buckles for easy fastening and longer length to allow it to be worn over a diving suit.

Bezel is set higher than the surface of the crystal to help protect it.
Large luminous hands and markers are designed for clear readability.

Please refer to the Instruction Booklet for "Periodical Check," "Pre-Diving Check," and "Battery Change Instructions."

Dual timer: A watch that measures current local time as well as at least one other time zone. The additional time element may come from a twin dial, extra hand, sub dials, or other means.

Dual Timer: A watch that measures current local time as well as at least one other time zone. The additional time element may come from a twin dial, extra hand, sub dials, or other means.

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E

E.O.E.: End of Energy. System used with the AHP alerts the wearer of accumulator discharge by causing the seconds hand to jump every four seconds instead of every second. The accumulator can the be recharged by turning the crown.

E.O.L.: End of Life. In quartz movement the end of battery life is indicated by the seconds hand which starts to jump every four seconds. The battery should be changed immediately.

Electroplating process: Process of covering metal articles with a film of other metals. The article is immersed in a chemical solution; electric current (D.C.) flows through the solution from a piece of metal (anode) to the article (cathode), depositing metal thereon by electrolysis. metals which can be used for plating are: 1) gold—a precious metal generally yellow in color; 2) chrome—can be white or black; 3) palladium—a precious metal, generally white; 4) ruthenium—also a precious metal but usually gray.

Elapsed Time Rotating Bezel: A graduated rotating bezel used to keep track of periods of time. The bezel can be turned so the wearer can align the zero on the bezel with the watch's seconds or minutes hand. He/she can then read the elapsed time off the bezel. This saves him/her having to perform the subtraction that would be necessary if he used the watch's regular dial.

Engine Turning: Decorative engraving, usually on the watch face.
Escapement: Device in a mechanical movement that controls the rotation of the wheels and thus the motion of the hands.

ETA: One of the leading manufacturers of watch movements based in Switzerland. ETA movements are used by many major Swiss watch brands.

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F

Face: The visible side of the watch where the dial is contained. Most faces are marked with Arabic or Roman numerals to indicate the hours. Interestingly, when Roman numerals are used, it is traditional to use IIII, rather than IV, to indicate the 4 o'clock position.

Fly back hand: A seconds hand on a chronograph that is used to determine lap or finishing times for several competitors in race. To operate, put both the fly back and the regular second hand in motion, then to record a lap or finishing time, the fly back hand can be stopped. After taking the results, push a button and the fly back hand will catch up to the constantly moving second hand.

Frequency: The number of vibrations a second, in hertz (Hz).

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G

Gold: Yellow precious metal which is stainless and very malleable. Used in alloys to make jewelry, bracelets and watches. The portion of gold in the alloy is indicated in carats (k).

Gasket: Most water resistant watches are equipped with gaskets to seal the case back, crystal, and crown to protect against water infiltration during normal wear. It is important to have the gaskets checked every two years to maintain the water resistance of the watch.

Gear Train: The system of gears which transmits power from the mainspring to the escapement.

Gold plating: A layer of gold that has been electro-deposited onto a metal; its thickness is measured in microns.

Grande Sonnerie: A type of repeater that sounds the hours and quarter hours when the wearer pushes the button.

Guilloche: A style of intricate engraving that is popular on watch dials, usually very thin lines interwoven to create a surface texture.

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H

Hands: The pointing device anchored at the center and circling around the dial indicating hours, minutes, seconds and any other special features of the watch.

Alpha Hands: A slightly tapered hand
Baton Hands: A narrow hand sometimes referred to as a stick hand.
Dauphine Hands: A wide, tapered hand with a facet at the center running the length of the hand.
Luminous Hands: Hands made of skeleton form with the opening filled by a luminous material.
Skeleton Hands: Cut-out hands showing only the frame.
Hard metal: A scratch-resistant metal comprised of binding several materials, including titanium and tungsten-carbide, which are then pressed into an extremely hard metal and polished with diamond powder to add brilliance.

High-Tech Ceramic: Used as a protective shield for spacecraft reentering the earth's atmosphere, high-tech ceramic is polished with diamond dust to create a highly polished finish. Because the ceramic can be injection molded, pieces can be contoured. It has a very smooth surface and is usually found in black, but can be produced in a spectrum of colors.

Horology: The science of time measurement, including the art of designing and constructing the timepieces.

Hourly time signal: Single beep/chime which rings on the hour, every hour when it is engaged.

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I

Index: An hour indicator on an analog watch dial, used instead of numerals.

Integrated Bracelet: A watch bracelet that is integrated into the design of the case.

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J

Jewels: Synthetic sapphires or rubies that acts as bearings for gears in the mechanical watch, reducing friction.

Jump Hour Indicator: A jump hour indicator takes the place of an hour hand. It usually shows the hours by means of a numeral in a window.

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K

Kinetic: Based on a revolutionary technology, Seiko, Kinetic watches run entirely on sell generated energy from natural movement of your wrist. It never needs a battery.

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L

Lap Memory: The ability, in some quartz sport watches, to preserve in the watch's memory the times of laps in a race that have been determined by the lap timer. The wearer can recall these times on a digital display by pushing a button.

Lap Timer: A chronograph function that lets the wearer time segments of a race. At the end of a lap, he/she stops the timer, which then returns to zero to begin timing the next lap.

LCD: Liquid-crystal display. This digital time display is used by longines to give additional chronograph indications.

Lighted dials: Several types of lighted dials are used so that you can tell time in the dark. Recently, a patented night-lite process, called electro-luminesce, lights the entire dial with a uniform light that makes for easy reading in nighttime situations. A side button activates the light. This technology often appears under a name brand such as Timex' Indiglo or Seiko's LumiBrite.

Limited Editions: A watch style manufactured in a specific amount, often numbered, and available in limited quantities. Limited editions are available from most fine watch manufacturers and may be highly prized by collectors.

Liquid-Crystal Display: A digital watch display that shows the time electronically by means of the liquid held in a thin layer between two transparent plates.

Lugs: Projection on the watch face to which the watch band/bracelet is attached.

LumiBrite: environmentally safe illumination technology that will glow brightly for hours without pushing a button or drawing energy from a battery.

Luminous: self illuminating paint used on hands and markers.

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M

Manual: A hand-wound mechanical watch.

Mechanical: Describes a movement with a balance wheel.

Main Plate: Base plate on which all the other parts of a watch movement are mounted.

Mainspring: The driving spring of a watch or clock, contained in the barrel.

Marine Chronometer: Highly accurate mechanical or electronic timekeeper enclosed in a box (hence the term box chronometer), used for determining the longitude on board ship. Marine chronometers with mechanical movements are mounted on gimbals so that they remain in the horizontal position is necessary for their precision.

Measurement Conversion: A feature, usually consisting of a graduated scale on the watch's bezel, that lets the wearer translate one type of measurement into another -- miles into kilometers, for instance, or pounds into kilograms.

Mechanical Movement: A movement based on a mainspring which is wound by hand; when wound, it slowly unwinds the spring in an even motion. An automatic mechanical requires no winding because of the rotor, which winds the mainspring every time you move your wrist.

Micron: Unit of measurement of the thickness of the gold-coating. 1 micron = 1/1000mm.

Military or 24-hour time: When time is measured in 24-hour segments. To convert 12-hour time into 24-hour, simple add 12 to any p.m. time. To convert 24-hour time into 12-hour time, subtract 12 from any time 13 to 24.

Mineral glass: Watch glass that has been tempered to increase its scratch resistance.

Minute repeater: A complication on a watch that can strike the time in hours, quarters, or seconds by means of a push piece.

Moon phase: A window in a watch face that shows which phase the moon is. A regular rotation of the moon is once around the earth every 29 days, 12 hours, and 44 minutes. once set, the moon phase indicator accurately displays the phase of the moon.

Mother-of-Pearl: Iridescent milky interior shell of the freshwater mollusk that is sliced thin and used on watch dials. While most have a milky white luster, mother-of-pearl also comes in other colors such as silvery gray, gray blue, pink and salmon.

Movement: The inner mechanism of watch that keeps time and moves the watch's hand, calendar, etc. Movements are either mechanical or quartz.

Mystery Watch: A patented invention of watchmaker Vincent Calabrese and produced by Jean Marcel, a Swiss manufacturer, the Mystery automatic mechanical watch uses no hands to indicate hours, minutes or seconds. Rather a jumping hour window moves clockwise around a minute scale while a second indicator, an arrow, also ticks around. Gently breathing on the crystal causes the word "mystery" to appear.

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N

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O

Oscillation: The travel of the balance wheel from one extreme to the other and back again. See Vibration.

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P

Pedometer: A device that counts the number of strides taken by the wearer by responding to the impact of the wearer's steps.

Perpetual Calendar: A calendar that automatically adjusts for the months' varying length and for leap year. Perpetual calendars, which can be powered by quartz or mechanical movements, are programmed to be accurate until the year 2100. Many watch collectors suggest storing mechanical versions in motorized winding boxes when they aren't being worn in order to maintain the calendar countdown.

Plating: Coating a metal base with another metal. In watch making a stainless steel base is coated with gold seven to 20 microns thick.

Platinum: One of the rarest of precious metals, platinum also is one of the strongest and heaviest, making it a popular choice for setting gemstone jewelry and watches. It has a rich, white luster, and an understated look. Platinum is hypoallergenic and tarnish resistant. Platinum used in jewelry and watches is at least 85 to 95 percent pure. Many platinum watches are produced in limited editions due to the expense and rarity of the metal.

Polished: Brilliant metal surface obtained on the watch-case with fine abrasive.

Power Reserve: The amount of energy reserve stored up to keep a watch running until it stops. The remaining power is sometimes indicated by a small gauge on the dial. For mechanical watches it is usually 44 hours. For quartz watches it can vary from 18 moths to 10 years.

Power Reserve Indicator: A feature of a mechanical watch that shows how much longer the watch will operate before it must be wound again.

Pulsimeter: Scale on a chronograph watch for measuring the pulse rate.

Push-piece: Button that is pressed to work a mechanism. (The push-pieces on chronographs, striking watches, alarms, etc.)

PVD: Physical Vapor Deposition. Method of coating thin watch cases by integrating titanium particles and then depositing gold for color.

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Q

Quartz: A natural or commercially synthesized silicon dioxide crystal. Used in "quartz analog" or solid state digital watches. When activated by a battery or solar power, the thin sliver of crystal very predictably vibrates at an extremely high frequency (32,768 times per second) thus providing very accurate timekeeping. The main components are: an Electric Circuit Block (Quartz Oscillator and CMOS-IC) and the Mechanical Block (step motor, gear train, hands) and a battery.

Quartz Movement: A movement which allows a watch to keep time without being wound. This technology employs the vibrations of a tiny crystal to maintain timing accuracy. The power comes from a battery that must be replaced about every 1.5 years. In recent years, new quartz technology enables the watch to recharge itself without battery replacement. This power is generated via body motion similar to an automatic mechanical watch, or powered by light through a solar cell, or even by body heat. A digital quartz watch has no mechanical parts. Most quartz movements are made in Hong Kong, Japan or Switzerland.

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R

Ratchet bezel ring: A bezel ring which can either turn one way (counter clockwise) or both ways and generally clicks into place.

Repeater: A device that chimes the time when the wearer pushes a button.

Rose (or pink) Gold: A softly hued gold that contains the same metals as yellow gold but with a higher concentration of copper in the alloy. A popular color in Europe, rose gold in watches is often seen in retro styling or in tricolor gold versions. Some 18k red gold watches achieve their color from additional copper in the alloy.

Rotating Bezel: A bezel (the ring surrounding the watch face) that can be turned. Different types of rotating bezels perform different timekeeping and mathematical functions.

Rotor: The part of an automatic watch that winds the movement’s main spring.

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S

Sand-blasting: Creating a granular metal finish by using a high-pressure jet of sand.

Sapphire Crystal: A crystal (the cover that protects the watch face) made of synthetic sapphire, a transparent shatter-resistant, scratch-resistant substance.

Sapplex Crystal: Combination of sapphire and hardlex crystals.

Screw-Lock Crown: A crown which aids water resistance by sealing the crown against the case. The seal is achieved by the matching of a threaded pipe on the case with the crown's internal threads and gasketing while twisting the crown to lock it into place.

Seal: Synthetic gaskets that seal the joints between parts of the case and keep out the wet.

Second Time-Zone Indicator: An additional dial that can be set to the time in another time zone. It lets the wearer keep track of local time and the time in another country simultaneously.

Shock Absorber: Resilient bearing which, in a watch, is intended to take up the shocks received by the balance staff and thus protects its delicate pivots from damage.

Shock Resistance: As defined by the US government regulation, a watch's ability to withstand an impact equal to that of being dropped onto wood floor from a height of 3 feet.

Shot-blasting: A satin finish obtained by using tiny glass pellets, one or two microns in diameter.

Skeleton Case: A case with a transparent front or back that allows the wearer to view the watch's movement.

Slide Rule: A device, consisting of logarithmic or other scale on the outer edge of the watch face that can be used to do mathematical calculations.

Solar Compass: A compass that lets the wearer determine the geographical poles by means of a rotating bezel. The wearer places the watch so that the hour hand faces the sun. He then takes half the distance between the position and 12 o'clock, and turns the bezel until its "south" marker is at that halfway point. Some quartz watches have solar compasses that show directions on an LCD display.

Solar Powered Batteries: Batteries in a quartz watch that are recharged via solar panels on the watch face.

Solid State: A timepiece with no moving parts. All digital watches are 100% solid state. Analog watches combine solid state circuits with moving parts.

Split time measurement: Measures the elapsed time of a certain moment of an event.

If you want to know the elapsed time at a certain point during a track meet, you can tell exact time by using this.

The chronograph keeps running while split time is being displayed. Therefore, when split time is released the display returns to original measurement of total elapsed time.

Stainless steel, an extremely durable metal alloy (chromium is a main ingredient) that is virtually immune to rust, discoloration, and corrosion; it can be highly polished, thus resembling a precious metal. Because of its strength, stainless steel is often used even on case backs on watches made of other metals.

Split Seconds Hand: Actually two hands, one a fly back hand the other a regular chronograph hand. When the wearer starts the chronograph, both hands move together. To time laps or different finishing times, the wearer can stop the fly back hand independently while the regular chronograph hand keeps moving, in effect "splitting" the hand(s) in two.

Stainless Steel: An extremely durable metal alloy (chromium is a main ingredient) that is virtually immune to rust, discoloration and corrosion; it can be highly polished, thus representing a precious metal. Due to this and the importance of white metal jewelry, steel has become a popular setting for diamonds. Because of its strength, stainless steel is often used even on casebacks of watches made of other metals.

Strap: A watch band made of leather, plastic or fabric.

Subdial: A small dial used for any of several purposes, such as keeping track of elapsed minutes or hours on a chronograph or indicating the date.

Sun/moon indicator: A wheel on a watch partially visible through a cut-out window indicating a sun and moon on a 24-hour basis.

Stepping Motor: The part of a quartz movement that moves the gear train, which in turn moves the watch's hands.

Sterling Silver: A white and highly reflective precious metal. Sterling silver refers to silver that is 92.5 percent pure, which should be stamped on the metal, sometimes accompanied by the initials of the designer or the country of orgin as a hallmark. Although less durable than stainless steel and other precious metals, sterling silver is often employed in watches that coordinate or look like sterling silver jewelry. A protective coating may be added to prevent tarnishing.

Stopwatch: A watch with a seconds hand that measures intervals of time. When a stopwatch is incorporated into a standard watch, both the stopwatch function and the timepiece are referred to as a "chronograph".

Subdial: A small dial on the watch face used for any of several purposes, such as keeping track of elapsed minutes or hours on the chronograph or indicating the date.

Swiss Made: A watch is considered Swiss if its movement was assembled, started, adjusted and controlled by the manufacturer in Switzerland.

Swiss A.O.S.C. (Certificate of Orgin): A mark identifying a watch that is assembled in Switzerland with components of Swiss orgin.

Sweep Seconds-Hand: A seconds-hand that is mounted in the center of the watch dial.

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T

Tachymeter (also tachometer): A watch function that measures the speed at which the wearer traveled by means of a numeric scale on the watch bezel of a chronograph. Frequently used to determine a speed of a car over a measured distance.

Tank Watch: A rectangular watch designed by Louis Cartier. The bars along the sides of the watch were inspired by the tracks of tanks used in World War I.

Telemeter: A telemeter determines the distance of an object from the observer by measuring how long it takes sound to travel that distance. Like a tachymeter, it consists of a stopwatch, or chronograph, and a special scale, usually on the outermost edge of the watch face.

30-Minute Recorder (or register): A subdial on a chronograph that can time periods of up to 30 minutes.

Timer: Instrument used for registering intervals of time (durations, brief times), without any indication of the time of day.

Titanium: The "space age" metal, often used with a silver-gray appearance. Because it is 30 percent stronger and nearly 50 percent lighter than steel it has been increasingly used in watch making, especially sport watch styles. Its resistance to salt water corrosion makes it particularly useful in diver's watches. Since it can be scratched fairly easy, some manufacturers use a patented-coating to resist scratching. Hypoallergenic.

Tonneau Watch: A watch shaped like a barrel, with two convex sides.

Totalizer: A mechanism that keeps track of elapsed time and display it, usually on a subdial.

Tourbillon: A device in a mechanical watch that eliminates timekeeping errors cause by the slight difference in the rates at which a watch runs in the horizontal and vertical positions. The tourbillon consist of round carriage, or cage, holding the escapement and the balance. It rotates continuously at the rate of once per minute.

Tritium: An isotope of hydrogen that is used to activate the luminous dots or indices on a watch dial. The radioactivity released in this process is too slight to pose a health risk.

Two Tone: A watch that combines two metals, usually yellow gold and stainless steel in the case of fine watches.

12-Hour Recorder (or Register): A subdial on a chronograph that can time periods of up to 12 hours.

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U

Uni-directional Rotating Bezel: An elapsed time rotating bezel, often found on divers' watches, that moves only in a counterclockwise direction. It is designed to prevent a diver who has unwittingly knocked the bezel off its original position from overestimating his remaining air supply. Because the bezel moves in only one direction, the diver can error only on the side of safety when timing his dive. Many divers' watches are ratcheted, so that they lock into place for greater safety.

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V

VHP: Very High Precision. A quartz movement with a temperature sensor to keep rate variations to within extremely narrow margins. The movement corrects itself to a precision of ?0 seconds a year.

Vibration: Movement of a pendulum or other oscillating element, limited by two consecutive extreme positions. The balance of a mechanical watch generally makes five or six vibrations per second (i.e. 18,000 or 21,600 per hour), but that of a high-frequency watch may make seven, eight or even ten vibrations per second (i.e. 25,200, 28,800 or 36, 000 per hour).

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W

Waterproof: An illegal and misused term. No watch is fully 100 percent waterproof.

Water Resistance: A water resistant watch can handle light moisture, such as a rain or sink splashes, but should not be worn swimming or diving. If the watch can be submerged in water, it must state at what depth it maintains water resistance, i.e. 50 meters or more on most sport watches. Below 200 meters, the watch may be used for skin diving and even scuba diving depending upon the indicated depths.
Sometimes water-resistance is measured in atmospheres (ATM), which is equal to 10 meters of water pressure. (Some European-made watches use the term "bar" instead). Straps other than metal bracelets may not be water-resistant. New water-resistant versions of nylon, rubber, and other synthetics are a trend in sport watches.

Watches come in different water resistant depths and diver's depths:

Water resistant—Will withstand splashes of water or rain but should not be worn while swimming or diving.
Water tested to 50 meters (165 feet)—Suitable for showering or swimming in shallow water.
Water tested to 100 meters (330 feet)—Suitable for swimming or snorkeling.
Water tested to 150 meters (500 feet)— Suitable for snorkeling.
Water tested to 200 meters (660 feet)—Suitable for skin diving.
Diver's to 150 meters—Meets ISO Standards and is suitable for scuba diving.
Diver's to 200 meters—Meets ISO Standards and is suitable for scuba diving.
White Gold: Created from yellow gold by incorporating either nickel or palladium to the alloy to achieve a white color. Most watches made of white gold will be 18k.

White On: An analog watch that is able to display digital functions at the touch of a button. An easily legible white numeric display appears on the inside surface of the crystal when any digital function is activated.

Winding: Operation consisting in tightening the mainspring of a watch. This can be done by hand (by means of the crown) or automatically (by means of a rotor, which is caused to swing by the movements of the wearer's arm).

Winding Stem: The button on the right side of the watch case used to wind the mainspring. Also called a "crown".

World Time Dial: A dial, usually on the outer edge of the watch face, that tells the time up to 24 time zones around the world. The time zones are represented by the names of cities printed on the bezel or dial. The wearer reads the hour in a particular time zone by looking at the scale next to the city that the hour hand is pointing to. The minutes are read as normal. Watches with this feature are called "world timers".

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X

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Y

Yacht Timer: A countdown timer that sounds warning signals during the countdown to a boat race.

Yellow Gold: The traditionally popular gold used in all gold, gold and stainless steel, or other precious metal combinations. Yellow gold watches may be found in 14k or, as found from most European manufacturers, 18k.