In 1999, the Datograph from A. Lange & Söhne ushered in a new era for the complication of short-time measurement, with a manufacture calibre newly developed from the ground up and a unique dial design. To mark its 25th anniversary, the pioneering chronograph is now available as a DATOGRAPH UP/DOWN model version in 18-carat white gold with a blue dial, limited to 125 watches
The Datograph was the prelude to a range of currently 13 innovative models with a chronograph function. Among these is the calibre L951.6 of the Datograph Up/Down: presented in 2012, it featured a power-reserve indicator and an increased power-reserve of 60 hours. With its flyback mechanism, precisely jumping minute counter, outsize date, and power-reserve indicator the timepiece is in a league of its own.
Because three switching steps are executed with one single push of a button, the flyback mechanism allows two quick consecutive time measurements, with virtually no delay between these. The chronograph is stopped, reset to zero, and started again in next to no time. The precisely jumping minute counter does justice to its name as well: it jumps to the next increment at the precise moment when the chrono seconds hand completes the 60th second. The attribute “Up/Down” refers to the power-reserve indicator at 6 o’clock that provides information on how much of the 60 hours’ power reserve is still available. At the latest on the third day, when the hand pivots into the red section, it is time to wind the watch.
Thanks to the harmonious dial configuration, the watch is easily identified. The twin date aperture beneath 12 o’clock marks the tip of an equilateral triangle. The subsidiary dials for the small seconds at 9 o’clock and for the precisely jumping minute counter at 3 o’clock are located below the horizontal centre axis of the dial, forming the base of the triangle. The characteristic, axially symmetric dial design assures optimum legibility. In its latest version, the timepiece is available in blue with rhodié-coloured subsidiary dials, luminous hands, and baton hour markers.
The technical sophistication, complex architecture, and the superior finishing of the manually wound calibre L951.6 ‒ consisting of 451 parts, assembled twice ‒ sets benchmarks in engineering and aesthetic appeal. The classic column-wheel chronograph with a freely oscillating balance spring and a balance with eccentric poising weights beats at a frequency of 18,000 semi-oscillations per hour (2.5 hertz) and allows time measurements with an accuracy of one-fifth of a second. Through the sapphire-crystal caseback, the minute counter mechanism and the column wheel, which controls the start and stop sequences, can be admired in action.
The timepiece is now available in three model versions, while the dimensions remain unchanged. The case boasts a diameter of 41.0 millimetres and a height of 13.1 millimetres. In addition to the new edition in white gold with a blue dial limited to 125 pieces, the model is also still available in a platinum/black and pink-gold/black case/dial combination.
