Chronograph

A chronograph is a timepiece with a separate function for measuring how long an event lasts. Timing can be started, stopped and reset while the watch also displays ordinary time. A chronograph is therefore more than a dial with several small hands.

Hands and counters

A chronograph may have separate counters for elapsed minutes and hours. The ordinary seconds hand and chronograph seconds hand can have different roles and positions. Counter layout, timing range and resolution need to be checked for the specific model.

As a documented example, Longines' L688 instructions show small seconds, a separate chronograph seconds hand and counters for 30 minutes and 12 hours. These details apply to that movement configuration, not every Longines watch or every older chronograph.

Chronograph and chronometer

Chronograph describes a timing function. Chronometer concerns precision and testing against specified requirements. The words are not synonyms. A pulsometer scale is a conversion scale using a timed interval; it is not the chronograph mechanism itself.

Assessing a second-hand watch

Identify the reference and correct instructions before operating functions. Do not force stuck pushers. Record whether starting, stopping and resetting have been checked, and whether hands return to the specified starting positions. An untested function should be described as unknown, rather than fault-free. Document dial, hands, reference and known servicing in a condition report.

Next step: Browse OBA's second-hand wristwatches and read each watch's condition information. To offer a watch for sale, provide its reference and known operation when enquiring about buying and selling.

Sources: Fondation Haute Horlogerie on chronographs and Longines L688 instructions, pages 4 and 5.