This page describes the testing and final adjustments for a typical watch. Mechanical watches are tested in six positions at both full wind and + 24 hours plus 5 to 10 day test and power reserve. Standard tests performed for quartz watches. Water resistance testing as appropriate.

Mechanical Watches

I’ve chosen this Omega Seamaster (calibre 565) from the late 1960s which arrived in complete but non running condition.

The full service document for this watch is available here.

There are six basic positions that a mechanical watch is tested in:

Watchmaker showing watch test positions

If the performance in terms of amplitude (the swing of the balance) and the rate in seconds/day are good in all these positions, the watch should run well and accurately.

I use a Witschi Watch Expert IV and test the movement during the build when the base movement is complete, and then at the end of the build when the movement is cased. I was early user of this equipment and Witschi used my review in their newsletter here.

At full wind (plus 30 minutes rest) the details are:

For a non chronometer watch such as this, only 3 positions (CH, 6H and 9H) are usually specified for test with a typical rate variation of 25 seconds/day maximum allowed across the three.

Watchmaker showing timing results

Watchmaker showing timing results

Watchmaker showing timing results

A chronometer watch adds positions FH (CB) and 3H and has a tighter specification across all 5 positions, typically 12 seconds/day maximum across the five.

Watchmaker showing timing results

Watchmaker showing timing results

 

The position 12H is an unnatural one on the wrist and not usually specified for test but can add some information to issues with the watch.

Watchmaker showing timing results

The tests are run again after the watch has rested for 24 hours and the requirements are more relaxed. I don’t usually show the results for these as isochronism has come into play and it’s not easy to explain.

As the data from the previous tests are just instantaneous points in time, I also run a longer term test, typically consisting of the following:

Day 1: Full wind, set time, mounted on the auto test machine (12 hours per day) – rested Dial up.
Day 2: Full wind, auto test machine (12 hours per day) – rested Dial up.
Day 3: Full wind, auto test machine (12 hours per day) – rested Dial up.
Day 4: Full wind, auto test machine (12 hours per day) – rested Dial up.
Day 5: Full wind, auto test machine (12 hours per day) – rested Dial up.

The average rate over the auto tester first five days of the test is roughly how I would expect this watch to run on the wrist.

     Day 6: Full wind, 24 hours rested in dial up position (typical wear position).
Day 7: Full wind, 24 hours rested in dial down position (atypical wear position).
Day 8: Full wind, 24 hours rested in 9H position (typical wear position).
Day 9: Full wind, 24 hours rested in 6H position (typical wear position).
Day 10: Full wind, 24 hours rested in 3H position (atypical wear position).
Day 11: Full wind, 24 hours rested in 12H position (atypical wear position).

These six days just confirm that the watch  runs well and accurately in all positions.

     Day 12: Full wind, rested in dial up position to check power reserve.
Day 13: Rested in dial up position to check power reserve.
These two days are only to check the power reserve.

The watch above averages +2.5 second/day over the five days of the test.

 

Quartz Watches

I also work on quartz watches and can perform all typical tests such as battery voltage under load, movement consumption, coil resistance, end of life activation and so on.

 

Water resistance testing

I also check water resistance of any watch suitable for such a test. The final test is always with a wet tester and the one I use covers up to 100m depth rating. This is shown at 60m plus a 25% safety factor.

Watchmaker showing water testing equipment