Caliber 440 movement serial number dating

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Barney Green
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Re: Caliber 440 movement serial number dating

#21 Post by Barney Green » Fri Feb 02, 2018 6:55 am

Hi Mike,

great work, I can confirm that it is a 100% fit to my movements.
And I would like to add once more that with your work you not only have decoded the 440 movement serials but also the ladies Curvex caliber 295.
The serials are definitely shared between those two movements.

Barney

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JackW
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Re: Caliber 440 movement serial number dating

#22 Post by JackW » Fri Feb 02, 2018 11:14 am

Mike, this is great work! You are to be commended.

To tighten it up and boost your augment, you need to show some statistics, such as the error or the root mean square. That in combination with your primary data will make it more bullet proof.

...or did I miss this somewhere?
All I know is based on hard work & writing by others. I can only aspire to augment this body of knowledge. If I am wrong it is because of my own failings. -me
"If I have seen farther it is by standing on the shoulders of giants." - Newton

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MikeTheWatchGuy
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Re: Caliber 440 movement serial number dating

#23 Post by MikeTheWatchGuy » Fri Feb 02, 2018 11:15 am

Didn't miss it. I'm good thanks.
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MikeTheWatchGuy
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Re: Caliber 440 movement serial number dating

#24 Post by MikeTheWatchGuy » Sat Feb 03, 2018 6:25 am

Here's a final version of the graph of the data.

Reasons for not posting a big analysis of the std. deviation, etc, is that it's a non-linear curve, the data has been posted for over a year with regular updates, and there are many more families of movements and case manufacturers left to decode.

As always, I'm happy to field corrections, criticism, questions and what-not. I'm moving on to the remaining, unsolved movement families and case manufacturers. Better to spend the time busting those than justifying the 440 data.

The table stands as built, for the moment. It survived one collection's lookups and I suggest with an error rate of +/- 1 or 2 years, I'm confident it'll hold up.
Gruen Caliber 440 Serials.jpg
Gruen Caliber 440 Serials.jpg (134.61 KiB) Viewed 570 times
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