Glossary

Is a feature found in some watches that allows the user to measure the distance between the watch and a visible or audible event. It is typically used to determine the distance of a lightning strike or other events. For example, the chronograph hand is activated upon seeing the lightning and stopped upon hearing the thunder.

The Telemeter scale is usually placed on the outer edge of the watch dial or on a subdial. It works based on the principle of sound transmission through the air at a known speed. When observing the event, such as a lightning flash, the wearer starts the chronograph function. The wearer stops using the chronograph when hearing the sound of the event, such as thunder. By reading the corresponding point on the Telemeter scale where the chronograph hand stopped, the user can approximate the distance of the event.