GLOSSARY OF WATCH TERMS

Mechanical (Automatic) vs Quartz

A mechanical watch has a number of practical advantages. It is more than accurate enough for daily life, is very durable, and if well maintained can be handed down from generation to generation as a precious heirloom or keepsake. A good mechanical watch is often more accurate over a short period of time, such as a 5 second interval, than a quartz watch; many professional photographers have discovered that using a mechanical watch to time their exposures gives more accurate results. Mechanical watches are also impervious to low levels of magnetism. Mechanical watches have no battery, are perfectly safe to the environment, and as a self contained, perpetually regenerating source of energy, show a respect and concern for nature. A mechanical watch is now, more than ever before, a practical, useful, and efficient mechanical device.

How accurate is an Mechanical Watch?

Depending on the movement used, the average daily rate will be between +30/­5 seconds per day. These rates are within the tolerances set by some companies such as Oris and cover both automatic and hand-winding watches.

How do quartz watches work?

Any timekeeping device will contain at least three different parts: a drive mechanism, an escapement device (way of measuring time), and a method of display. A windup alarm clock, for example, uses a tension spring as a drive mechanism, an escapement wheel, and the gear driven mechanical hands moving across the clock face as a display of the time. Generations of timepieces through history have worked to improve accuracy. Early mechanical clocks used falling weights as drive devices and a verge and foliot as an escapement device. The verge was a gear tensioned by a weight and the foliot was a ratchet type device that oscillated back and forth on the verge in a hold release pattern creating the familiar tick tock sound of clocks. Escapement wheels in mechanical clocks of today use much the same concept. The discovery of the pendulum by Galileo provided an even more accurate method of timekeeping as the frequency of the pendulum’s swing is not affected in time by its amplitude. In other words, even as the pendulum’s swing weakened in amplitude, the frequency between cycles remained constant. Having a timepiece that was portable also had its challenges. Pendulum clocks don’t work well in motion. Spring driven clocks give portability, but run faster when newly wound and progressively slower as the spring relaxes. Electric clocks were an improvement, but with still relatively low frequency escapement at 60 cycles per second, were not extremely accurate.

What is a chronometer?

A watch of extremely high precision and accuracy, tested in several positions and under different temperatures and which has obtained an official rating certificate from the COSC. The COSC (Contrôle Officiel Suisse des Chronomètres) is an independent association. It gives a rating certificate for each chronometer which has successfully passed the test.

What is a complication?

Additional functions to a watch movement, e.g. chronograph, second time zone, alarm, calendars, etc.

What is a jewel or ruby?

Synthetically produced precious stone of artificial sapphires or rubies that have been drilled, chamfered, and polished to serve as bearings for the gears and as stones for the pallet-arms. This reduces the friction of mechanical parts against each other to a bare minimum. A good watch requires at least 15 jewels. Automatic watches, because they have so many more gears and moving parts, sometimes have as many as 25 jewels.

What is a tachymeter?

The tachymeter division on the dial of a chronograph serves to measure the speed, e.g. of a car on a measured course of 1 km or 1 mile. At the moment the car passes the starting point of the course, the chronograph is set and stopped at the final point of the course. The position of the stopped hand on the tachometer scale corresponds to the speed in km (miles) per hour. The speed over the whole test run must be the same.


Water Resistance Ratings

30m Rating – Can withstand accidental, short-term exposure to moisture from splashing, rain or sweat. Submersion in water is not acceptable.

50m Rating – Moderate exposure to moisture and moderate short-term submersion will not damage the watch.

100m Rating – Submersion in shallow water acceptable. Showering and other similar exposure to moisture can be tolerated.

200m+ Rating – Watch has been designed for diving. Specifications for each model will vary and should be reviewed before use.