This section contains user manuals for popular stopwatches and chronometers.
Stopwatch — a device for measuring time intervals with an accuracy of fractions of a second. Typically, stopwatches measure with an accuracy of 1/10 and 1/100 of a second. The accuracy of mechanical stopwatches is usually 1/10 sec. With modern technology, it became possible to measure time much more precisely – down to ten-thousandths of a second and beyond. Stopwatches with laser finish detection have an accuracy of 1/1000 sec. and higher. Stopwatches allow for start and stop of time counting, as well as recording intermediate intervals (lap time).
A timer is a device for industrial, military, or household use that issues a specific signal or turns a device on/off at a set time. Generally, timers are devices that measure a set time interval from the moment they are started, functioning as a countdown stopwatch. There are also timers that trigger at a specific time of day (real-time timers); in such cases, the timer includes a clock or a timekeeping device. The simplest timer of this type is an alarm clock.
A chronometer is a highly precise clock whose accuracy is certified by the Swiss Official Chronometer Testing Institute (Controle Officiel Suisse des Chronometres, COSC). To receive certification, watch mechanisms are tested for 15 days for accuracy in five positions (vertical, horizontal, etc.) under three different temperatures. The acceptable accuracy range for mechanical chronometers is -4/+6 seconds per day. Standards also exist for quartz chronometers, which are much stricter at only ±0.07 seconds per day. A chronometer can also refer to a precise portable balance wheel timepiece used in astronomy, geodesy, and navigation.
User Manuals for Stopwatches, Timers, Chronometers, Tachometers |