A watch altimeter is a special function that will measure your elevation or height above sea-level, recording ascent and descent by responding to changes in barometric pressure. Typically found in flight or pilot watches, it’s similar to the component found in the cockpit of an airplane. While this function is important for pilots, it also serves useful for mountain climbers or sky divers.
Atmospheric pressure is the result of the weight of the atmosphere pushing from above versus the downward force of gravity. The higher the point in the atmosphere, the lower the atmospheric pressure. An altimeter measures changes in atmospheric pressure to calculate altitude in feet or metres above mean sea level. The most common altimeters are barometric. A chamber inside contains a stack of sealed aneroid wafers, which have an internal pressure equal to standard barometric pressure at sea level. The wafers expand and contract with changes in static pressure (the name given to atmospheric pressure at the level an aircraft is flying). As a plane descends, static pressure increases, contracting the wafers and causing them to collapse. This is indicated as a decrease in altitude. During ascent, static pressure decreases, allowing the wafers to expand. This is indicated as an increase in altitude.To compensate for changing weather conditions and to ensure the altimeter reading is correct, an altimetermust be calibrated to a known pressure value at take-off, for example, current air pressure at mean sea level.
Knowing your current height above sea level might not be something of importance to most people in everyday life. You might be a serious mountain climber who’s live depends on knowing your current height, but will you then rely on your G-Shock? Though nice as a gadget on your digital watch, an altimeter on a mechanical watch is a rare find and a serious complication for watch enthousiasts.
Traditional mechanical watches boast only few features with additional functions. From this point of view, mechanical watches certainly do not match electronic and smart watches. In order to spark the interest of watchmakers, a potential complication should meet several basic requirements: be compact enough to fit the watch case without critical increase of its size; be produced according to ‘analog’ methods and finally it should have some practical value in the eye of potential customers. Welcome the new kid in town: the integrated altimeter that shows the altitude by measuring atmospheric pressure.
Mechanical watches that measure elevation
First place in the adaptation of this device to the watches belongs to the young brand Breva, which unveiled the Génie 01, a model equipped with an altimeter and barometer at the Baselworld in 2013. It’s a miniature weather station that fits perfectly into the case, measuring “only” 44.7mm in diameter and 15.6mm in thickness.
Another watch with an altimeter comes from the Oris Big Crown ProPilot Altimeter – see picture above.
FAQ
What is a watch altimeter?
A watch altimeter measures the height above sea-level according to changes in the barometric pressure.
Why do you need an altimeter on your watch?
Your current elevation above sea-level will tell you how much you’ve ascended or descended and give an indication about oxygen levels.
Who needs an altimeter on their wrist?
This function serves useful for cyclists, snowboarders, mountain climbers and sky divers.
What kind of watches have an altimeter?
Some great examples of watches with altimeter include the Breva Genie 01, the Garmnin Fenix X5 and the Oris Pro-Pilot Altimeter.
