The F.P.Journe Centigraphe Sport in details

The hand-wound mechanical movement of the Centigraphe indicates elapsed times from a 100th of a second to 10 minutes, visible on 3 dials, each with a time scale in red.

The indications
The 100th of a second hand revolves around the dial in one second on a scale marked in hundredths of a second.
On the dial at 2 o’clock, the hand revolves once every 20 seconds on a time scale divided into seconds.
The third dial, at 6 o’clock is graduated for 10 minutes.

Patented ergonomic chronograph
The chronograph is started, stopped and zeroed by a rocker at 2 o’clock in the case band, instead of the usual buttons on either side of the crown. This ergonomic design, perfectly fitted to the wristwatch, is patented.

Patented chronograph mechanism
A second patent was granted for the mechanism’s ingenious configuration, which effectively isolates the chronograph from the timekeeping function. This means the balance amplitude is unaffected when the chronograph is running.
The hands of the 100th of a second counter, the 20 seconds, and the 10 minutes hand are driven by 2 different wheel trains, themselves driven by the centre of the mainspring (patented).
Another separate train of wheels, also driven by the barrel arbor, drives the 10-minutes hand.

1/100th second recorder hand
The 100th of a second’s hand, released by the watch's escapement, makes one revolution of the dial per second. A wheel mounted on the escape wheel (4th wheel of the going train) releases the arbor to which the hand is fitted. The seconds are driven by the going train from the barrel, and by the energy of the chronograph train, as transmitted by the barrel arbor.
One ingenious feature of the 100th of a second is that it may be stopped anywhere along its one-second journey around its dial, even between two 100th-second divisions, enabling a fractional reading.
This is achieved by vertically disengaging the pinion of the 100th of a second hand from that of the escapement, which presses on the pivot shank and acts as a brake.

Return to zero
The 20-seconds hand and the 10-minutes hand arbors are zeroed by hammer levers acting on snail cams. The 100th of a second hand is stopped at zero by a beak protruding from its pinion, which presses on a lever and thus blocks the chronograph train.

Maintaining power and power reserve
The barrel features a maintaining power system in order to ensure that the driving force does not decrease during winding.

The mainspring supplies at least 100 hours of power reserve without the chronograph, and 24 hours with the chronograph running.