Mechanical watches
Precision tolerances3
OMEGA  mechanical watches with a certified chronometer 
movement
OMEGA watches bearing the chronometer inscription (in accordance 
with the certificate issued by your authorised OMEGA retailer) are 
high-precision timepieces that have passed the precision tests of the 
Official Swiss Chronometer Testing Institute (Contrôle Officiel Suisse 
des Chronomètres, COSC).
This neutral and independent body individually tests each movement 
for 360 consecutive hours, during which it is placed in the five common 
wrist positions and exposed to three different temperatures.
To earn the title of chronometer, the mechanical movement’s average 
daily variation in rate must be between -4/+6 seconds per day, or a 
precision of 99.99%, the highest precision attainable by a mechanical 
movement.
U
9, 101 , 2 7 , 83 , 4 5 , 6
13
23°C
38°C
12
23°C
23°C
14, 15
23°C
23°C
11
23°C
8°C
23°C
Temperature
Temperature
Days
Days
Position
Position
Quartz watches
Precision tolerances3
The precision of a mechanical movement depends on the individual 
habits of the wearer and can therefore vary. A qualified OMEGA 
watchmaker can adjust the precision of a watch to within the OMEGA 
tolerances, which are from -1 to +6 seconds per day.
Other OMEGA mechanical watches 
Watches without chronometer  certification  (COSC) have average  
precision tolerances of between -1 and +11 seconds per day.
The precision of a mechanical movement depends on the individual 
habits of the wearer and can therefore vary. A qualified OMEGA 
watchmaker can adjust the precision of a watch to within the OMEGA 
tolerances. 
Quartz watches
All OMEGA quartz movements are produced in accordance with 
OMEGA’s highly renowned procedures and quality standards. Ambient 
temperature may affect the precision of quartz movements, which can 
lead to variations of between -0.5 and +0.7 seconds per day.
Quartz watches with thermocompensation 
This movement is fitted with an electronic module that compensates 
for the effects of temperature on the movement’s precision. These 
watches are accurate to within +/- 0.055 seconds per day.
The precision of a mechanical watch cannot be compared to that of a 
quartz watch, given that the two are based on different technologies.
U
01-OMEGA_V14-I_EN.indd   34-35 16/05/12   14:01:20