A Chronograph for Measuring Pulse

Added to the 1815 series in 2004, the "1815 Chronograph" is a timepiece that ideally fuses advanced technology with traditional design. The layout, with railway-track-inspired minute markers encircling the dial and a symmetrically placed small seconds subdial on the left and a 30-minute counter on the right, evokes the pocket watches A. Lange & Söhne once produced.

The scale on the outer edge of the dial is for measuring pulse rate. Using this scale, one can determine pulse rates from 40 to 200. To find the pulse rate per minute, time how long it takes for 30 beats to occur using the stopwatch. Then, read the number of beats per minute indicated by the hand on the scale.

The calibre of the 1815 Chronograph, boasting a 60-hour power reserve, was developed in 2010 and incorporates a proprietary free-sprung balance spring. This balance spring, along with the precisely coordinated balance wheel with eccentric cams, ensures a stable rate. The balance wheel oscillates at 18,000 vibrations per hour, or 2.5 Hz, enabling measurements in 1/5-second increments.

Through the sapphire crystal exhibition case back, one can admire the chronograph movement, adorned with elaborate decorations throughout. Furthermore, the design allows for an unobstructed view of the complex workings of the chronograph mechanism. This makes the movements of the column wheel, the levers of the flyback mechanism, and the snail-shaped cam that drives the precision jumping minute counter clearly visible.

The escapement reveals a beat error corrector, adjustable for fine-tuning, mounted on the hand-engraved balance cock—a hallmark of Lange watches—and held by a swan-neck spring.

1815 Chronograph

Movement | Manual-winding (Lange Manufacture Calibre L951.5)
Power Reserve | 60 hours when fully wound
Functions | Small seconds with stop seconds, Flyback chronograph with precision jumping minute counter
Case Material | 18K White Gold
Case Diameter: 39.5mm
Case Back | Sapphire Crystal
Strap | Hand-sewn alligator
Price | JPY 5,430,000 (excluding tax) *Please inquire about stock availability in advance.