Chronograph A watch equipped with a separate measuring mechanism and a separate seconds hand (chrono hand) that allows the measurement of short time intervals (stopped times).

Disconnector mechanism Complex device within the rattrapante mechanism that prevents mechanical friction when the rattrapante hands are stopped but the chronograph hands are still running

Flyback This complicated mechanism in the movement of the DATOGRAPH allows the user to instantly set the chronograph seconds hand to zero during an ongoing measurement. When the push-piece is released again, a new measurement starts without delay. This transforms the conventional sequence of "stop", "set to zero", and "start" steps into one single step.

Precisely jumping minute counter This is a function in Lange's chronographs that makes it easy to read stopped times. During a measurement, the minute counter does not advance gradually but instead jumps to the next minute marker when precisely 60 seconds have elapsed.

Double rattrapante Beyond the simple "stop watch" function, a rattrapante chronograph also allows lap-time measurements, time comparisons, and the determination of the fastest or slowest of several laps. With conventional rattrapante chronographs, these measurements are confined to the seconds scale and thus limited to a duration of 60 seconds. The double rattrapante mechanism developed by Lange has an additional rattrapante hand for the minute counter. This makes it possible for the first time to meaningfully exploit the rattrapante functions - for events that last up to 30 minutes.

Sapphire crystal Glass made of artificially produced sapphire. It is very hard (9 on the Mohs scale) and scratch-resistant. It ranks just below the diamond in these two respects.

German silver Special alloy composed of copper and zinc, with a nickel concentration of about 10%. German silver is stronger than brass and has been traditionally used by Lange for the manufacture of plates and bridges. The addition of nickel minimises the oxidation of German silver and thus eliminates the need to electroplate the alloy - it can remain "untreated".

Glashütte ribbing A linear decoration. It is produced by a rotating grinding wheel that is slightly inclined and moved along the surface of the workpiece in parallel lines.

Chamfering Also: angling, bevelling. The breaking and polishing of sharp edges on bridges and levers. The inclined surface has the same width along its entire circumference or length.

Column wheel Also: ratchet wheel, sometimes pillar wheel. A steel switching wheel that has upright columns. It controls all important switching operations in a chronograph mechanism.

Perlage Also: circular graining. Cloud-like decoration on plates and bridges. It is produced by stippling the surface with a small rotating grinding wheel.

Eccentric poising weights Small, screw-like masses attached to the balance wheel rim. Their centre of gravity lies outside the axis of rotation. When they are turned, the position of their centre of gravity will shift and thus change the moment of inertia of the entire balance wheel. This causes it to oscillate somewhat faster or slower.

Escape wheel Together with the lever, it constitutes the escapement. It is the last wheel in the going train.

Adjusted in five positions The watch is timed for accuracy in the positions in which it is most often worn: dial up and down, winding crown up and down, and horizontal.

Gold chaton The gold setting of a bearing jewel - in Lange watches, chatons are often secured to the three-quarter plate with two or three screws.

Precisely jumping minute counter This is a function in Lange's chronographs that makes it easy to read stopped times. During a measurement, the minute counter does not advance gradually but instead jumps to the next minute marker when precisely 60 seconds have elapsed.

Synthetic ruby Friction-reducing, wear-resistant functional jewel for bearings, switching elements, and clicks. Its crystalline structure is more homogeneous than that of natural ruby.

Semi-oscillation Also: vibration. Half of the path travelled by the balance wheel from end point to end point.

It is a world unto itself: The newly developed Lange L001.1 mechanical movement. With a diameter of 30.6 mm and a height of 9.45 mm, this compact calibre packs a prodigious amount of timekeeeping technology. A glance through the | sapphire crystal caseback reveals the complicated rattrapante mechanism with the characteristic split-seconds clamp. The mechanism also embodies an ingenious system of levers that implements the | rattrapante function in the minute counter axis. Located one level deeper, the | chronograph, | flyback, and | minute-counter mechanisms are still partially visible. A new patent-pending | disengagement mechanism developed by Lange minimises mechanical friction when the rattrapante hands are stopped while the chronograph hands are still running. All parts of the movement are painstakingly finished by hand. The plates and bridges made of untreated | German silver are decorated with | perlage and | Glashütte ribbing; all edges are | chamfered and polished. This also applies to the whiplash spring and to the two classic | column wheels. Further design features and highlights in the movement of the LANGE DOUBLE SPLIT: - Lange's recalculated | balance spring, manufacture-made to ultra-high quality standards - Newly developed, free-sprung balance with | eccentric poising weights and 21,600 | semi-oscillations per hour - Four screwed| gold chatons - 40 synthetic | ruby jewels to minimise mechanical friction - Four-jewel | escape wheel bearing system - Mirror-polished cover plate for the escape wheel bridge - Separately assembled fourth-wheel and minute-counter bridges both for the chronograph and for the rattrapante - Stepped pinion with a synthetic | ruby sliding head for the precisely jumping | minute counter - Movement adjusted in | five positions.