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In the professional
watch terminology, the words “chronograph” and “chronometer”
have a very different signification. Many consumers and sometimes
even professionals don’t make the difference!
Well then, let us try to define both items.
The chronograph is a mechanical or quartz
watch displaying besides hours, minutes, seconds and possibly the
date, through a centre jumping hand the calculated seconds, a 1/10
or even a 1/100 of a second with a minutes and often an hours counter
in a little display.
Push buttons allow the user to set in motion the chronograph function,
i.e. the calculation and display of short times and to stop it.
A chronograph is at first a sport’s watch, but can be useful in
science, medicine, cooking, etc.
You can find different pattern of chronographs.
The most famous is the chronograph “rattrapante” (fly back)
equipped with two centre jumping hands instead of only one.
The second hand allows the user to measure several times starting
together but having a different duration. At the end of the first
time measure, the second hand stops and the user can read the covered
time.
After some seconds, this hand flies back to the first one. Both
carry on their run together until the next measure.
Among the mechanical with manual or automatic winding mechanism
and the quartz chronographs, often called multifunctional, one of
the most famous is the ETA 13 ¼’’’ movement 251.265 with double
display, analogical and numerical (LCD) with the following functions:
- display of hours, minutes, seconds, small jumping
seconds at “6 o’clock”
- time zone mechanism -stop-second device
- numerical date display programmed for 4 years,
- numerical chronograph 1/100 second (LCD)
- counters: 60 seconds, 30 minutes, 12 hours
- function ADD: adding up of the start time - stop
- start - stop - etc.
- function SPLIT: record of intermediate times
cumulatively
- function LAP: time keeping of successive laps
- alarm device (LCD)
- battery end-of-life indicator (EOL)
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The chronometer
is a mechanical or quartz watch of high precision which obtained
an official rating- certificate issued by the Swiss Institute for
Official Watch Time-keeping Office (in french COSC).
To accede to this
certificate, each watch has to go through a number of strict tests:
the COSC will control every subjected piece in different positions,
and let them go through thermal cycles in order to check their precision
at different temperatures (sweating-rooms at 8°C, 23°C and 38°C).
If the running variations don’t exceed the maximum tolerances decided
for each test, the submitted pieces are acknowledged and officially
attested as “chronometer”. Such a control gives the user
the guarantee that his “chronometer” is of high running and production
quality.
The requirements
of the official rating-certificate are not the same for mechanical
and quartz products due to the fact that the quartz watch has a
resonator oscillating 32'768 times a second which confers a very
high precision and a stronger stability.
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