Beat Error...to Correct Or Not Correct?

[Don]

I finished assembly of one of my project movements, a Caravelle 11DP (Citizen 0201). Before I started, I put the watch on the timing machine to get a baseline. The results were:

 

D/U

Rate: +31s/d

Amplitude: 240°

Beat Error: 0.6ms

 

After cleaning, oiling and reassembly, the results were:

 

D/U

Rate: +18s/d

Amplitude: 296°

Beat Error: 0.9-1.0 ms

 

I'm happy about the rate improving, but I'm not happy to have increased the beat error. Is .9ms a big deal? Is it worth futzing with? The balance doesn't have a moveable hairspring stud.

 

Is the amplitude of 296° high?

 

Thanks in advance.

 

Don

[clockboy]

If it was me I would just move the adjuster to the minus a touch. Providing your not getting snow on the screen then it is in beat.

[Geo]

Providing your not getting snow on the screen then it is in beat.

If you are getting snow, there is more wrong than just beat error. The beat error is indicated by how far apart the traces are on the timing screen, ideally they should be superimposed on each other and only show one line. The watch will run just fine with the error that you have and as Clockboy says you could just make a small rate adjustment.

[Don]

Thank you, Clockboy and Geo. I'll try to adjust the timing. The graph looks pretty good.

 

[Geo]

A couple of minor adjustments and it will be virtually spot on! Well done. :)

[Don]

Thanks, Geo. After I get the hands on it and case and put the new crystal on it I'll show it off.

Edited February 3, 2015 by Don

[clockboy]

Thats a good reading,  just a tweak more & job done.