LONGINES Ultra-Chron. High-Frequency 5 Hz = 36.000 A/h. “Ultra Chronometer Officially Certified”

In 1968, Longines launched the Ultra-Chron Diver, the first dive watch to be equipped with a high-frequency movement. At the time, Longines had already established itself as a pioneer in high-frequency technology. In fact, the winged hourglass brand created its first high-frequency timekeeping device to measure precisely 1/10th of a second as early as in 1914. In 1959, Longines developed the first high-beat movement for a wristwatch, an observatory chronometer that set new records in terms of accuracy.

The new Longines Ultra-Chron is inspired by the aesthetic codes as well as the professional dive features of the 1968 model. It features a unidirectional rotating bezel as well as a screwed-in caseback and crown. It also offers great legibility and is water resistant to 30 bar (= 300 meters).

The Longines Ultra-Chron’s 43 mm cushion-shaped steel case is fitted with a diving bezel that boasts a sapphire insert with luminescent accents. The black grained dial features a white minute track with alternating Super-LumiNova®-coated batons and rhodium plated appliques.

The original Ultra-Chron logo is applied on the dial and embossed on the caseback. The new Longines Ultra-Chron has a distinctive red minute hand which, like the hour hand, is coated with Super-LumiNova® for optimal legibility.

The new Longines Ultra-Chron is powered by the “in house” calibre L836.6, a high-frequency movement. A watch is referred to as “high-frequency” when it is fitted with a movement whose balance-spring oscillates at 36,000 A/h (= 5 Hz or 1/10 of a second).

These movements, which Longines pioneered in 1914 (to time 1/10th of a second) and 1916 (to time 1/100th of a second), improved precise timekeeping. From 1959 onwards, Longines made use of the high-beat-movements to increase the accuracy of its watches. Thanks to a reduction of the disruptive effects of shocks or of changes in the position of the movement, the high-beat movement proved to be more stable.

The accuracy of the Longines Ultra-Chron is confirmed by its certification as an “ultra chronometer” by TIMELAB, an independent testing laboratory in Geneva.

The “ultra chronometer” certification by TIMELAB goes beyond the usual “chronometer” certification. The “ultra-chronometer” qualification process tests the watch-head and subjects the finished product to a 15-day testing period during which the watch is submitted to a series of tests at three temperatures, 8°C, 23° C and 38°C, confirming that it meets the strict precision criteria (ISO 3159:2009 standard).

The Longines Ultra-Chron is available with a choice of a leather strap or a steel bracelet and it is delivered in a special presentation box containing a black NATO strap crafted from recycled material.

REFERENCE NUMBERS L2.836.4.52.9 L2.836.4.52.8

“Ultra-Chronometer” watches officially certified by TIMELAB Geneva

High-frequency mechanical self-winding movement

Calibre L836.6 11½ lines, 25 jewels, 36’000 vibrations per hour (= 5 Hz) with silicon balance-spring, Power reserve: around 52 hours

Hours, minutes, seconds

Diameter 43.00 mm, 13.60 mm thickness “Cushion” shape, stainless steel
Unidirectional rotating bezel with sapphire insert, Super-LumiNova® Screwed crown and screw-down case back
Special engraving on the case back with the “Ultra-Chron” logo and “ULTRA-CHRONOMETER officially certified” mention

Black grained 4 applied silver indexes with Super-LumiNova® underneath Original applied “Ultra-Chron” logo

Rhodium-plated (hours, seconds), red (minutes) Super-LumiNova® (hours, minutes)

To 30 bar (300 meters)

Sapphire glass box with several layers of anti-reflective coating on both sides

Stainless steel bracelet with double safety folding clasp and push-piece opening mechanism and an additional black NATO strap made of recycled material.

Sold in a special wooden watch box with a tool to change straps. Brown leather strap with buckle and an additional black NATO strap made of recycled material. Sold in a special wooden watch box wit