Credits: Article and images by Sarah Lee @ Revolution Watch Magazine. See the original article here - https://revolutionwatch.com/introducing-the-high-frequency-longines-ultra-chron/
Replacing the groundbreaking caliber 431 is the current high-frequency, self-winding caliber L836.6, with a silicon hairspring that is resistant to corrosion and brushes off temperature variations and magnetic fields without skipping a beat. It beats at 10Hz or 36,000 vibrations per hour. Those thousands of vibrations are energy-hungry, something that usually translates to a shorter power reserve. Longines has managed to squeeze 52 hours out of one barrel, which is decent. To test the robustness of the L836.6, Longines has turned to another independent testing laboratory based in Geneva called TIMELAB.
Unlike COSC, TIMELAB certifies completed, cased watches and not just the movements themselves. The lab runs through a range of tests over a period of 15 days before it can be certified by TIMELAB to have met the “Observatoire Chronométrique+” standard, or as Longines simply calls it, an “ultra-chronometer”. This designation takes pride of place on the caseback, inscribed above every other marking.
Credits: Article and images by Sarah Lee @ Revolution Watch Magazine. See the original article here - https://revolutionwatch.com/introducing-the-high-frequency-longines-ultra-chron/