kronométer

Kronométer is a term used in horology to denote a timekeeping device of high precision, capable of maintaining accurate time under various conditions. Historically it referred to a marine chronometer—an especially robust clock or watch designed for navigation at sea—and today it is commonly used for timepieces that have earned an official chronometer certification. The word derives from chronos, time, and metron, measure.

The need for accurate timekeeping at sea led to major developments in the 18th century. Governments sponsored the creation of reliable marine clocks to solve the longitude problem. John Harrison’s sea-going chronometers, culminating in the H4 around 1761, demonstrated that a clock could keep sufficient time at sea to determine longitude with acceptable accuracy. This breakthrough revolutionized navigation and commerce, making chronometers essential tools for maritime travel. Early chronometers emphasized resistance to motion, temperature changes, and humidity, often employing gimbals and precise gear trains.

In modern horology, chronometer also denotes watches that pass formal accuracy testing by independent authorities. A chronometer may be mechanical or quartz and is characterized by stringent performance standards. The Swiss Official Chronometer Testing Institute (COSC) is a prominent example of such certification, testing movements in multiple positions and under varying conditions. To earn chronometer status, a movement must meet a typical standard of about -4 to +6 seconds per day.

Today kronométer-linked timepieces span from traditional marine chronometers to chronometer-certified wristwatches. While atomic clocks and coordinated universal time (UTC) provide global time standards, chronometer-certified devices are valued for precision, reliability, and historical significance in horology and navigation.