I have a watch with an Asian 7750 movement with 28800 bph. It shows an average -005 s/d rate and an average 0.4 ms beat error. Can somebody translate me, what does this mean? Is it a good watch or not? How many seconds will show (as an error) in + or - per each day?
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Question about rate and beat error
- Thread starter al_pacino
- Start date
Beat error is basically a measurement of 'slop' in the movement, specifically the difference in times between the balance swinging all the way one way and all the way back the other way... beat error can change drastically based on position and problems with the movement, and the strength of the hair spring.
0.4ms isn't a bad error rate, especially for an Asian replica movement and you are losing 5 seconds a day on average, which may regulate out easily... Not too bad at all...
I would be more interested in the amplitude when wondering about the health of the movement... hopefully something above 270 degrees when fully wound.
0.4ms isn't a bad error rate, especially for an Asian replica movement and you are losing 5 seconds a day on average, which may regulate out easily... Not too bad at all...
I would be more interested in the amplitude when wondering about the health of the movement... hopefully something above 270 degrees when fully wound.
Amplitude on different positions is between 292 and 300 degrees... What does this mean...I don't know...:wacko:
And how can I fix that 5 seconds error per day? Should I wait 1 month, and then correct those -2.5 minutes, by advancing the watch with 2.5 minutes? :thinking:
PS. The watchsmith told me that the watch was already regulated, so there is any chance to regulate it further more than this?
And how can I fix that 5 seconds error per day? Should I wait 1 month, and then correct those -2.5 minutes, by advancing the watch with 2.5 minutes? :thinking:
PS. The watchsmith told me that the watch was already regulated, so there is any chance to regulate it further more than this?
Personally I think beat error of .4 is rather high. Most watchsmiths, myself included, strive to adjust for .1 or lower. But I have shipped rep watches out with quite high beat error if there are hairspring or other issues that prevent it from being stable with lower beat error. Par for the course when you're dealing with reps.
As for the average -5 seconds/day rate, that's actually fine for a rep if it plays out in the real world (rate can vary quite a bit when worn or put on the winder). Remember COSC chronometer specification calls for +6 to -4. You're only 1 second outside of those limits.
But beat and rate numbers only tell part of the story in real time. Sort of like the speedometer in your car - it only tells you how fast the vehicle is going but doesn't tell you if the engine is running properly. You really need a Vibrograph analysis or equivalent to tell if the tick lines are straight and parallel.
As for the average -5 seconds/day rate, that's actually fine for a rep if it plays out in the real world (rate can vary quite a bit when worn or put on the winder). Remember COSC chronometer specification calls for +6 to -4. You're only 1 second outside of those limits.
But beat and rate numbers only tell part of the story in real time. Sort of like the speedometer in your car - it only tells you how fast the vehicle is going but doesn't tell you if the engine is running properly. You really need a Vibrograph analysis or equivalent to tell if the tick lines are straight and parallel.
Check out this example of a watch recently sent in to me:
The real-time rate during the screenshot is +10 seconds/day and the beat error is .5 or below. Not too bad, and some folks might be happy to get similar performance from their rep. But I assure you if you received this rep you would be most disappointed. See the zig-zag tick pattern? The movement was in terrible shape and erratic, going from running very fast to running very slow. The inconsistent hairspring and out-of-round wheels led to galloping and seizing. And the issues could not be resolved.
Just an example of how a Vibrograph-type analysis will speak volumes more than just generic beat and rate numbers.
The real-time rate during the screenshot is +10 seconds/day and the beat error is .5 or below. Not too bad, and some folks might be happy to get similar performance from their rep. But I assure you if you received this rep you would be most disappointed. See the zig-zag tick pattern? The movement was in terrible shape and erratic, going from running very fast to running very slow. The inconsistent hairspring and out-of-round wheels led to galloping and seizing. And the issues could not be resolved.
Just an example of how a Vibrograph-type analysis will speak volumes more than just generic beat and rate numbers.
Nice explanation.
Isn't it interesting how manufacturers always manage to describe their products by the properties that show them it the best light but choose to ignore the things that have a real impact to the end user.
Isn't it interesting how manufacturers always manage to describe their products by the properties that show them it the best light but choose to ignore the things that have a real impact to the end user.