Reading timegrapher

[east3rn]

Hello. 

I am working on a vtg. Citizen cal.7520 automatic movement.

I have put the watch on the timegrapher 

The graph looks OK but the beat error shows 9.9ms. I presumed that beat error should be around 1.0~2.0 given the shape of the graph.

Is the beat error actually bad or the timegrapher is wrong??

Thank you!

 

[jdm]

What happens is that drawing of the exit line carry over so it may viisually overlap. The reading of more than 9.9ms is correct. Already years ago I had opened a topic with the same issue, you can find it with the search function. 

[Doninvt]

Different issue, but the subject line seems to fit.

I'd guess the discontinuities come every turn of the escape wheel.  It happens in the 12 down position but not 12 up or horizontal. In those positions there's just a little burp.  Loose jewel?