Today, as well, there remain situations in which people are obliged to rely on the accuracy of their chronometers. This accuracy is ensured by independent chronometer testing authorities, the majority of which have thus far been located in Switzerland. At the beginning of 2006, however, Wempe began collaborating in Glashütte with the state offices for weights and measurements of Thuringia (LMET) and Saxony (SLME) to establish the sole German testing facility for wristwatch chronometers in accordance with the German DIN norm.
To earn the right to be called a chronometer, a watch must prove the accuracy of its rate during a standardized testing procedure, and the timepiece’s precision must be certified by an official testing authority. The reason for this elaborate process becomes understandable when one considers the historical background that led to the invention of the chronometer.
As late as the mid-eighteenth century, most mariners were unable to precisely determine their position at sea because they lacked a reliable means of measuring time. This knowledge is essential for the calculation of a ship’s current longitude. Unnecessary detours and seagoing accidents were frequent consequences. This unsatisfactory situation persisted until 1759, when Englishman John Harrison invented the chronometer. Harrison succeeded in constructing a timepiece so accurate that it could be used to calculate the difference between the time at the vessel’s home harbour and the actual time on board, also making it possible to determine longitude. Combined with the known latitude, the two values precisely indicated the vessel’s current position.