Two Telemeter Scales on My Chronos

Not two different scales, but rather two differently graduated Telemeters scales on a couple of my mechanical chronos.

Here is one - the 2011 Океан Final Edition

The telemeter scale is in red on the outside of the hour marks and it is apparently graduated in nautical miles having about 10 units in total, that is, measuring the distance up to 10 nautical miles or thereabout.

And here is the other - my 2013 Strela 3133 45 mm by Volmax.

Here the scale is in kilometers and has about 19 units.

Basically the telemeter is a device used to measure distances to remote objects.

Per wikipedia,

...the telemeter chronograph is a feature of a wristwatch, i.e. a complication (and the chronograph is itself a complication) which allows the user to approximately measure the distance to an event that can be both seen and heard (e.g. a lightning bolt or a torpedo strike) using the speed of sound. The user starts the chronograph (stopwatch) at the instant the event is seen, and stops timing at the instant the event is heard. The seconds hand will point to the distance measured on a scale, usually around the edge of the face. The scale can be defined in any unit of distance, but miles or kilometers are most practical and commonplace.

It is important to keep in mind different telemeter scales graduation to avoid simple errors.

HoroLex: Две шкалы "телеметр": Только сейчас обратил внимание на то, что среди двух моих хронографов со шкалой телеметр одна в морских милях, а другая в километрах. Океа...