Omega SA 1108, 2520, 2500, 1538, 1120, 1400 Perpetual calendar, Calibre 1680 fig, Thermocompensation

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Perpetual calendar

CALIBRE 1680 (fig. V)

The particularity of the Gregorian calendar is that one day (29th February) is added to the year every four years to compensate for the length of the solar year, which is 365.242192 days, or almost 365 1/4 days. Such years are called leap years and their number (e.g. 1996) is divis- ible by 4.

As the compensation of one day every four years is too much, every 100 years (2100, 2200, …) the year is not a leap year, even though it is divisible by four. However, even this is not totally sufficient, since it leaves an error of one day every 400 years. Therefore, if the number of the year is divisible by 400 it is a leap year, as was the case with the year 2000. Because of this, the perpetual calendar of your watch is set to function correctly until 2100.

Thermocompensation

This movement is 10 times more precise than a conven- tional quartz movement thanks to an electronic module that compensates for the effects of temperature on the movement’s operation.

The crown has 3 positions:

Watch functions:

1.1.Neutral position 1, normal when the watch is worn: in this position, the crown ensures that the watch is water-resistant.

1.2.Setting the hands: minutes and seconds.

Pull the crown out to position 3 when the second hand is at 12 o’clock. The seconds hand will stop. Turn the crown forwards or backwards to set the minute hand.

Push the crown back into position 1 to coincide with a given time.

English

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NOTE: To avoid inadvertently changing the date when setting the time, it is important to always follow point 1.2 and then point 1.3.

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Contents
Operating Instructions Viii Xviii Contents What are the service intervals? Special recommendationsEnvironmental protection Leather strapsAnti-reflective treatment Screw-in crownOmega International Warranty Valid for U.S.A. onlyOmega SA Rue Stämpfli 96, 2500 Bienne Omega International Warranty Above manufacturer’s warranty Calibres 1426, 1530, 1532 fig Quartz WatchCalibres 1376, 1456 fig Calibres 1424, 1538 figCalibre 4000 fig. IIbis Time setting by pressing the correctorCalibres 1424 Watch functions Quartz chronographCalibre 1270 fig Chronograph functionsSimple timing function crown in position Pusher B ResetCalibre Pusher a Start stop read timePusher a Stop to read time Pusher a Press again to restart Addition function crown in positionPusher a Start Pusher a StopCalibres 1120, 2500, 2520, 2610 fig 2627 fig. III 2300 fig Power reserve cal Counter at 9 o’clock small secondsManual & Self-winding watch Calibre 2201 Manual-winding Power reserveCrown has 2 positions Calibres 3205 fig. XV 3220 fig. Xiii 3601 Pusher B reset after a stopSelf-winding chronograph Regatta function calApnea function based on a 14 minute dive Regatta functionApnea function cal Changing the date press the corrector C at 10 o’clock Self-winding chronograph with dateCalibre 3304 fig Calibre 1151 fig Self-winding split seconds chronograph Watch functions calibreSelf-winding split seconds chronograph Chronograph functions with split secondsManual-winding chronograph Calibres 1861, 1863 fig. XV 1866, 3604 figCalibre 1866-Date and moon phase correction Date setting small counter at 12 oclock press corrector CCalibre 1680 fig Setting the hands minutes and secondsPerpetual calendar ThermocompensationDisplay and correction of the month Display and correction of the yearly cycle Self-winding GMT & GMT Chronograph Calibres 1128 fig. VI 2628 fig 3603 figSelf-winding GMT & GMT Chronograph Bi-directional turning bezel calibre Coincide with a given time signalSecond Time Zone calibre 1128, fig Second Time Zone calibre 2628, fig. VII, calibre 3603, figDays Position Temperature 23C Days 14,15 Position Temperature 23COther Omega mechanical watches Precision tolerances32 -1 to +6 seconds per day Quartz watchesPressure is gradually increased to Helium escape valveHelium escape valve fig How to use the helium escape valve fig Not functional, since it is screwedExample calculating the speed of a car Using the tachymetric scaleTachymetric scale Rubber strap Rubber strap Snap-fastening foldover clasps Opening Adjusting the lengthFoldover clasps ClosingClosing fig Adjusting the length figFoldover clasps with pushers Opening fig Pictograms
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