Oris Big Crown Telemeter Chronograph

Telemeter. Most of the chronograph watches are equipped with tachymeter scales to help you determine speed. The Oris Big Crown Telemeter Chronograph has a telemeter scale on the bezel, which is used to determine the distance of an event with an audible rapport.

It works simply enough. At sea level sound travels at 340.29 meter per second. So if you see a lightning bolt hit ground and start counting seconds until you hear the loud crackling sound you can estimate how far from you it landed. If you were able to count to five seconds, than it would have been about 1700 meters (or 1.7 km) away (5 x 340.29). The Oris Big Crown Telemeter Chronograph lets you do the same thing, more precisely.



The Oris Big Crown Telemeter Chronograph. The The Oris Big Crown Telemeter Chronograph belongs to Oris line of aviation watches. It is really a historical piece with little present day relevance. Most pilots now would prefer to wear a dual time watch with air traffic controllers, and other instruments and tools, helping him to measure the distance between his aircraft and a thunderstorm. It was not always that way, and once the telemeter was a pretty handy tool.

Other than the telemeter, the Oris Big Crown Telemeter Chronograph is a typical chronograph watch powered by a Oris modified ETA 7750 movement. The ETA modified movement produces 28,800 vibrations per hour. The dial has a small seconds sub-dial at the 9 o'clock position. The chronograph function uses the main seconds hand and 30-minute and 12-hour counter at the 12 o'clock and 6 o'clock positions, respectively.

It comes with the option for a brown leather strap or a bracelet. The casing is a fairly hefty 43mm wide with a water resistance rating of 30 meters.

The glass. It has a slightly domed plexi glass covering the dial with a clear mineral glass case back. On this matter, with many the low cost US$50 China watches available with sapphire crystal glass, it would be nice to see sapphire crystal glass in all watches in the future. I know sapphire cost more than plexi or mineral glass. How much would a sapphire crystal glass for the cover and case back add the US$1,415 retail price of the Oris Big Crown Telemeter Chronograph?

About Oris. Oris is a Swiss watch company founded by Paul Cattin and Georges Christian at Hölstein (Basel-Country) in 1904.