As an extension of the 1815 watch family, A. Lange & Söhne has unveiled a new version of the 1815 Chronograph with the stopwatch function, combining a 39.5-millimetre white-gold case and a black dial with a pulsimeter scale. The latest version of the classic A Lange & Sohne chronograph comes endowed with the calibre L951.5 movement, a power reserve of 60 hours and a manufactory-made free-sprung balance spring. Its carefully calibrated interaction with the large, cam-poised balance guarantees excellent rate accuracy. Because it beats at a frequency of 18,000 semi-oscillations per hour (2.5 hertz), the watch can measure times with an accuracy of one fifth of a second.The rhodiumed hands ensure superb legibility against the backdrop of a jet-black solid-silver dial. Additionally, heart rates can be determined with the pulsimeter scale on the outer ring of the dial, graduated from 40 to 200 beats. When the time for 30 beats is measured, the peripheral scale indicates the heart rate per minute. This new member of the 1815 family is underscored with a black alligator leather strap and a solid white-gold Lange prong buckle. A sapphire-crystal caseback provides an enlightening glimpse of the complex switching sequences, displaying the column wheel that controls the chronograph functions, the levers of the flyback mechanism, and the snail of the precisely jumping minute counter. The escapement is readily visible as well. Hallmarks of the Lange style include the whiplash spring of the precision beat-adjustment system on the hand-engraved balance cock.
