The Master Chronometer Certification

Raising
standards

Inside this timepiece are the revolutionary components that guarantee the highest standards of performance. From the Co-Axial escapement for long-lasting precision, to the silicon balance spring for superior anti-magnetism, OMEGA has conquered every challenge that matters.

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Raising standards

Greater precision

Every OMEGA Master Chronometer is tested twice. First, the movement is certified to the ISO 3159 chronometer standard with precision criteria of -4/+6 seconds per day or -5/+8 seconds per day, depending on the calibre size. Then the complete watch undergoes eight additional Master Chronometer tests set by the Swiss Federal Institute of Metrology (METAS), with pass criteria ranging from 0/+5 to 0/+7 seconds per day, depending on calibre size.
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Raising standards

Anti-magnetic

Everyday items such as mobile phones, metal clasps on handbags, laptops, MRI, induction hobs or automatic doors; subject a watch to magnetic fields and can affect its performance for good. To prevent the risk of permanent deviations of up to several minutes a day we've conceived movements with antimagnetic materials, such as the silicon balance spring, capable of withstanding the highest fields.
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Raising standards

Water-resistance

To ensure the integrity of our timepieces at depth, not just some but all watches are fully immersed in water and pressure is applied up to the point of the guaranteed water resistance. By submerging each watch in water we have chosen – yet again - to exceed normal testing standards.
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Raising standards

Durability

Every OMEGA Master Chronometer must pass eight stringent tests for accuracy, magnetic-resistance, power reserve and water-resistance. This certification supports a comprehensive 5-year warranty.

Discover the 8 tests

To achieve the Master Chronometer title, all movements and completed watches must face 8 stringent tests, which have been set by the Swiss Federal Institute of Metrology (METAS). As shown below, these examinations guarantee the highest standard of precision, performance, and magnetic resistance in the Swiss watch industry. Only perfectly functioning timepieces that pass every test will earn the certification.

Test 01

Function of movement during magnetic exposure
Test 02

Function of complete watch during magnetic exposure
Test 03

Chronometric precision: magnetised and demagnetised
Test 04

Chronometric precision day-to-day
Test 05

Chronometric precision in six positions
Test 06

Precision at low power reserves
Test 07

Power reserve testing
Test 08

Water resistance

Discover the 8 tests

Test 1 1

Test 2 2

Test 3 3

Test 4 4

Test 5 5

Test 6 6

Test 7 7

Test 8 8

Each movement is placed into a permanent "zero-energy-use" magnet and subjected to a strong magnetic field of 15,000 gauss.

Carefully-placed microphones monitor the ticking of the movements (tested in two different positions) to ensure their proper function in extreme magnetic conditions.

The movements are carefully assembled inside their cases and subjected to a further 15,000 gauss.

Microphones closely monitor the ticking of each watch to verify precision under extreme magnetisation.

Watches are rewound and fully magnetised in a field of 15,000 gauss.

At the start of day one a time 'stamp' is created by taking pictures of the watches hands and comparing their displayed times to an official METAS atomic clock.

Following a 24-hour wear simulation, a second set of images is captured to calculate the deviation between the time displayed and atomic time.

On day two, the 24-hour testing process is identical to day one, only this time, the watches are demagnetised.

At the conclusion of the 48-hour test we calculate deviations between the magnetised and demagnetised results to ensure there's no impact on precision and our watches fall within the strict tolerances set by METAS.

Each day the watches are rewound and exposed to the following conditions.

On wrist:
14 hours at 33 degrees Celsius with watches turned to different positions every 3 hours

Off wrist:
10 hours at 23 degrees Celsius with watches turned to different positions every 5 hours

The deviation between the time displayed and atomic time is recorded daily. After four days of wear simulation, these daily deviations determine whether the watch meets the required accuracy.

Only the minutest deviations in these daily averages are permitted for a watch to earn Master Chronometer status: 0–5 seconds per day, or a maximum deviation of 0.0058% over 24 hours — half that of the Chronometer standard.

Carefully positioned microphones register the ticking of the movements to calculate the precision of the watches.

Out of these six results, we establish the deviation between the two most extreme results known as the Delta, to ensure the movements are METAS compliant.

The watches are fully wound so the power reserve is at 100% (for example 60 hours).

Microphones register the ticking of the movements in six different positions in order to calculate precision.

The watches are left running until their power reserves reach 33% (for example 40 hours later).

Again, the movements are acoustically tested in six different positions.

We then take the average results of the measured precision during both states of the power reserve. The deviation between the two must fall within the tolerances set by METAS.

The watches are fully wound (power reserve at 100%).

The start time for the test is then recorded by photographing the position of the watch hands and comparing the reading to atomic time.

The watches are then left to function for the duration of their promised power reserve (e.g. 60 hours) before further pictures of the hands are taken to make a second atomic time comparison.

These readings must adhere to the power reserve standards set by METAS.

Watches are submerged in a water tank and pressurized; for minutes or many hours, and pushed to their limits at pressures from 3 bar (30m) to 150 bar (1500m) - depending on the watch.

Once taken out of the water, each watch is heated to reach a temperature between 40 and 45 degrees Celsius.

A drop of cold water is then placed on the sapphire glass of each watch by hand. If condensation appears, it shows that the watch does not comply with METAS standards.

NOTE: In order to ensure added safety and security for professional divers, the pressure is actually raised 25% higher than the stated water-resistance when testing divers' watches.

Testing Complete

When a timepiece passes all of these 8 examinations, it is officially rewarded with Master Chronometer certification.

Tested twice

For OMEGA, chronometer certification is only the beginning. Eight additional Master Chronometer tests take every watch beyond the industry standard. View your watch's results by entering its certificate number online.

Master Chronometer Watches

When OMEGA introduced its METAS-approved testing in 2015, the Globemaster was the first watch to emerge. Since then, the brand has subjected almost all of its mechanical timepieces to the stringent 10-day process.

See all models