Longines L651 - L442

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L442 Quartz chronographs
When used as a watch, the Longines L442 QUARTZ chronograph
indicates a local time (hour, minute and small seconds), plus the date
in a window, and features quick time zone adjustments.
In its chronograph function, this model can time events lasting up
to 30 minutes, while displaying the results to the nearest 1/10th of
a second. PowerDrive quick-moving chronograph counter hands.
PreciDrive rate precision, earning COSC certi cation.
Timing mode
Simple function
In this function, with the crown in position 1, push-piece A is used to
switch the chronograph status between START and STOP.
After START is pressed, the counter hands will show the measured
time. The 60-SECOND and SPLIT-SECONDS counters run simultane-
ously, indicating the measured time in seconds.
After STOP has been pressed, the 60-SECOND, SPLIT-SECONDS and
30-MINUTE counter hands will stop running. The 1/10th of a SECOND
counter hand displays the value in tenths of a second as it runs.
To measure another time, press push-piece B to return the counters
to zero (RESET). All the hands will quickly return clockwise to the start
point, and the chronograph will go back to watch mode.
Battery end-of-life mode (E.O.L)
(See page 87)
L442
2 31
PreciDrive calibre 251.294
• Electronic quartz movement with 5motors and 7 hands.
• Hour with time zone mechanism.
• The time measurement and hand movements are managed
by a microcontroller.
• The movement seconds are controlled by a PreciDrive Watch
Module, which transforms this calibre into a chronometer
with a rate precision exceeding the COSC requirements.
Minute hand
60-second counter
30-minute counter
1/10
th
of a second counter
Push-piece C
Push-piece A
3-position crown
Hour hand
60-second counter
(split-seconds hand)
Date aperture
Push-piece B
Small seconds
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