A quartz watch uses quartz for timekeeping and electronics for the other main functions, display and power.
A quartz watch is a timepiece that uses the oscillation of a quartz crystal to keep time, triggering a electrically-powered stepper motor to advance the wheel train, usually once per second. Although other timepieces (Seiko Spring Drive and Bulova Accutron, for example) include quartz crystals, these are generally not called quartz watches.
In a quartz movement, a crystal is made to vibrate. The uniform oscillation is now used to drive a motor with the help of a chip, ie an integrated circuit. This turns a gear train in the rhythm of the supplied pulses. Quartz watches do not contain a spring, balance wheel or escapement.
One advantage of this concept is the very high accuracy and the low space consumption, disadvantages are the environmental pollution by the battery and its dependence on the battery change.
With quartz watches there are essentially two display systems:
- digital display with light emitting diodes or liquid crystals
- analog hands, which are driven by a motor
Because of the required electric power most quartz watches have batteries. This makes it possible that the watch may stop suddenly - a fact which has to be urgently regarded especially at dive watches and which has once again led to develop mechanical dive watches, such as the GST Deep One by IWC.
Thermocompensation and Adjustment
Temperature plays a major role in the accuracy of a quartz movement. First- and second-generation quartz watch movements were generally not thermocompensated at all, leading to varying levels of accuracy. Even today, most quartz movements are second-generation CMOS circuits with no thermocompensation or other adjustments for accuracy.
There are three methods of fine accuracy adjustment in quartz movements:
- Automatically thermocompensated movements (e.g. Citizen High-Accuracy Quartz)
- Thermocompensated with calibration terminals (e.g. ETA Thermoline, Seiko 9F, Rolex OysterQuartz)
- Non-thermocompensated with calibration terminals (e.g. Jaeger-LeCoultre Mechaquartz)
Also known are solar watches by Junghans, Citizen or Casio, that draw their power from solar cells.
Economical aspects of the quartz watch
Because of the competition for the most accurate quartz watch and the most advanced technology, the Swiss watch industry collapsed late 1970s and early 1980s into their worst crisis (keyword: quartz crisis), from which in the meantime it nevertheless emerged strengthened again. This was mainly due to two things: the launch of the (quartz-driven) Swatch, which led the audience back to the Swiss watch, and secondly the successful renaissance of the mechanical watch in the luxury segment of the market.