There are further parts which are attached to the watch case and are not related to the movement directly. In the following, we would like to present some of the ones that feature our watches. Information on how to use them is provided in the section “Handling”.
The rotatable bezel has its origin in diver’s watches and serves for counting the time, starting at a particular minute. By this, the passed bottom time can be read, within which – in case of keeping to the rising speed when going up – no decompression is needed.
This scale is used for measuring the current speed. It is often combined with the chronographic function. Tachymeter scales usually indicate kilometers or miles per hour.
This scale allows the determination of distances and thus is often found in chronographs as well. The calculation grounds on the different velocities of propagation of light and sound. For example, the distance to a thunderstorm can be identified by starting the chronograph with the lightning and stopping it with the thunder. Depending on the calibration of the scale, the hand indicates the distance either in kilometers or miles.
Bezel with slide rule
Some bezels are equipped with slide rules for the multiplication and division of numbers. These special bezels are rotatable to both sides and derive from aviation. Additional functions that allow the calculation of rising and descending speeds, of fuel consumption or the conversion from kilometers in miles etc. are often integrated.