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Positional error

W

wes cobb

Information on the old pocket watches all state if they are adjusted for positional error and in how many planes. I have never seen this for wrist watches which certainly get into more positions than pocket watches. Can anyone explain this?
Wes
 
W

wes cobb

Information on the old pocket watches all state if they are adjusted for positional error and in how many planes. I have never seen this for wrist watches which certainly get into more positions than pocket watches. Can anyone explain this?
Wes
 
M

michael h schneider

Offhand, I can remember seeing Elgin wristwatch movements marked 'adjusted 4 positions'. Can't remember the model/grade numbers. I think I remember Waltham ww movements similarly marked.m
 
M

Mike Kearney

Interesting question and I don't think we've gotten to the bottom of it in the past.

Lots of wristwatches say adjusted and the number of positions. And wristwatches need adjustments for positions far more than pocket watches, because they move around a lot when being worn.

But most Swiss watches say 'Unadjusted' on the movement. Why? I think there's something about this in Kathy Pritchard's books, but I don't have them with me. As I recall, the American watch industry got Congress to put protective tariffs on Swiss watches. The tariff on a watch was related to the value of the watch. I believe the number of adjustments figured into establishing the watches value. The Swiss imported some very fine watches, which kept great time, marked 'Unadjusted'. I believe there were hearings in Congress as to whether these watches were properly marked, or if they were mismarked to avoid the tariff.

So it's my opinion that this wristwatch 'adjusted' issue is more complex than just whether they need to be adjusted for positions (which they do).

Can anybody help shed some light on the history of this?

Regards,
Mike
 

Don Dahlberg

Registered User
Aug 31, 2000
3,425
21
38
Positions are also important to wristwatches.

In pocket watches, the three most important positions are dial up, dial down and pendant (or 12) up. The latter being the way the watch was carried. Of lesser importance are pendant right and pendant left, which are only adjusted in 5 position watches. The least important is pendant down adjusted only in 6 position watches.

In a wrist watch, the 9 up or pendant down becomes the most important position. This is the way the watch spends much of its time on the left wrist.

Hamilton adjusted the following watches to three positions: 997, 989, 980, 982, 982M, 752, 753, 754, 770, 747, 748, 730, 735 and all 6/0 sizes. Four position watches included the 721 and 995. Five position watches included 911. 911M, 750, 751, 756 and 757.

The standards were not nearly so tight as for the pocket watches.

For example a 992B:
Pendant up within 0 to + 5 sec.
Between dial up and dial down 6 sec.
Between dial up, dial down and pendant up 10 sec
Between all positions except pendant down 15 sec
Between all 6 positions 20 sec.

For the 20/0 size 757:
9 up between 0 to +40 sec.
Between dial up and dial down 30 sec.
Between dial up and 9 up 60 sec.
Between all five positions 90 sec.

If you look at the many of the magazines that are dedicated to high end wrist watches today (for example International Watch, Watch Time, In Sync and others), you will see that they run tests on the watches, just like Road and Track runs tests on cars. You will see positional errors of 2 seconds or less on many of these watches. A Rolex does keep very good time. Of course you pay for such precision.

Don Dahlberg
 

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