2 New Essential Tools Coming This Month..........

Oh and one thing I should mention since this is a chronograph - the checks above are done with the chronograph stopped.

Cheers, Al

I would like to get a full set of timing results before I comment, so let's move on to part 2 of the testing. Fully wind the watch, wait for 30 minutes, and repeat the three timing tests, then we can discuss the timing results as compared to Omega standards.

I will say I'm surprised to see +70.

Cheers, Al

Okay so we have some good information here. Here is the information that Omega publishes for watchmakers as minimum requirements after a service is completed:



I have highlighted the Cal. 1861 information. From left it gives the Cal. as 1861, C or N and this is N for non-chronometer, beat rate of 21,600, lift angle of 50, 3 testing positions, and the stabilization and testing times.

Now for the actual tolerances. Looking further to the right you will see Amplitude 24 hours indicated as 190 degrees - this is the minimum amplitude in any position at full wind -24 hours. Your exceeds that, so you are good there.

Moving to the left now, max. beat error is 0.6 and your watch is good there, although most watchmakers strive for zero or as close as possible.

Now we come to the 2 Delta readings. So one is done at full wind -24 hours, and the other at full wind. This is the difference between the fastest and slowest rates over the 3 positions tested, and at 2 different states of wind. So if your watch was running say +10 in the fastest position and 0 in the slowest, the delta is 10. If it was -5 to +5, the delta is still 10, and -10 to 0, again 10.

For full wind the maximum delta is 15 seconds, and at full wind -24 hours, it's 20 seconds. For your watch the delta at full wind is 63 seconds (64-1) and for full wind -24 hours it's 68 seconds (70-2). This is well outside Omega specifications.

Moving to the left again, we see target rate at 0 hours (full wind) and it is +5 seconds per day. This is the average of the three readings at full wind. Then we have upper and lower limits for this average at -1 to +11. Your average is +24.7, so again, well outside Omega specifications.

So your watch is not running within Omega specs at this time. Although there are no specifications for it, the balance amplitude at full wind being about 260 in the horizontal position is a bit low. My "rule of thumb" s more for 270 as a minimum, and it's not unusual to see 300 degrees here.

Now you know what Omega specs are, and how your watch compares to them.

Cheers, Al

Could be several things - poise error, balance spring not centered, balance spring hitting something in that one position....difficult to say without seeing the watch.

Service intervals are a very individual thing, so it really depends on several factors. I don't have a universal answer for these things. I have no idea what condition the movement is in, or when it was last serviced.

If this deviation in rate bothers you, then you can certainly get it looked at. As I said, often collectors having these tools will cause more strife than pleasure.

Cheers, Al

Sometimes one finds out more than one wants to know 😁

You are welcome.

Cheers, Al