Yeah but those one second ticks that don't line up...

Thread: Yeah but those one second ticks that don't line up...

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  1. #1

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    Yeah but those one second ticks that don't line up...

    One of the jibes occasionally tossed at quartz watches by spring chauvinists is that the seconds hand moves in one second ticks and (in many cases) doesn't line up with the dial markings.

    Let's forget that the one second ticks thing was an expensive complication in mechanical watches (oh for a Milgauss tru-beat) how about the lining up?

    One of the causes of apparent misalignment is the dial and hands not being truly concentric. I reckon that a great number of watches are like this - mechanical and quartz. I reckon, also, that the stepping of a quartz seconds hand makes this misalignment more obvious. The smaller steps of a mechanical watches seconds hand will cause it to appear to pass over each of the marks on the dial and I think that the instantaneous position of the hand relative to these marks is the cue that people use to "see" misalignment. Seeing the misalignment in a mechanical watch would require a fifteen or twenty second image memory.

    Any opinions on this?

  2. #2
    Member Bruce Reding's Avatar
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    Re: Yeah but those one second ticks that don't line up...

    Good thought. You're right, of course, Robert. It would be amazing to me if mechanicals didn't have all the failure modes of quartz watches when it came to misalignment. It would just be impossible for one to see them with the naked eye. One would need specialized equipment. (A high speed video with an appropriately small field of view would do it.)

    This raises an interesting question. Many of these failure modes will cause inconstant offset. In other words, the offset of the seconds hand relative to the marker will vary as a function of location on the dial. This would constitute a direct error for chronographs. I wonder if the old mechanical stopwatches used in the Olympics and other premier athletic events were built to minimize this error? I know that they were very expensive.
    Last edited by Bruce Reding; March 7th, 2007 at 13:11.

  3. #3

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    Re: Yeah but those one second ticks that don't line up...

    Quote Originally Posted by Bruce Reding View Post
    I wonder if the old mechanical stopwatches used in the Olympics and other premier athletic events were built to minimize this error? I know that they were very expensive.
    That's a good point, I've had a quick Google to see if I could find anything about there being offset adjustments for dials - nothing. I have read of gently tapping the dial on some watches to shift it relative to the mounting holes (soft brass locating pins) but I'd imagine that proper sports timers would have a more positive dial fixing.

    It would have been easy to check for offsets photographically - a long exposure to allow the seconds hand to describe a full circle.

    Interesting - an area where quartz watches seem more finicky than their mechanical cousins.

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    Re: Yeah but those one second ticks that don't line up...

    Don't you think most of the current high-tech timing devices used in various sports that need accurate timing would be using digital read-outs today...... and for the last few years? I'm sure Formula 1 racing does, for example.

    I agree about the misaligned hands/dials though, I've noticed it in several of my own watches (all quartz) and the misalignment varies as a function of where you look on the dial. It's irritating but I don't know that there's much one can do about it. If anyone has a cure, I'd love to hear it. One more way to lower the blood pressure!

  6. #5
    Member lysanderxiii's Avatar
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    Re: Yeah but those one second ticks that don't line up...

    Quote Originally Posted by Bruce Reding View Post
    Good thought. You're right, of course, Robert. It would be amazing to me if mechanicals didn't have all the failure modes of quartz watches when it came to misalignment. It would just be impossible for one to see them with the naked eye. One would need specialized equipment. (A high speed video with an appropriately small field of view would do it.)

    This raises an interesting question. Many of these failure modes will cause inconstant offset. In other words, the offset of the seconds hand relative to the marker will vary as a function of location on the dial. This would constitute a direct error for chronographs. I wonder if the old mechanical stopwatches used in the Olympics and other premier athletic events were built to minimize this error? I know that they were very expensive.
    That's the reason why those official timers were a few thousand (in 1970's) dollars apiece.

    But, the biggest error in that type of timer is the human element; the average person's reaction time ia around 0.3-0.5 seconds.

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    Member Sgian Dubh's Avatar
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    Re: Yeah but those one second ticks that don't line up...

    Even without any specialized equipment, I can clearly see on my automatic that the second hand doesn't line up as it passes over each mark.

    I have an old Omega Deville that's quartz. The second hand lines up just fine, though the watch gains about five seconds per day. Some you win, some you lose.

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    Member M4tt's Avatar
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    Re: Yeah but those one second ticks that don't line up...

    Actually this problem is an awful lot more complicated than people are considering. The problem is to do with the fidelity, speed and accuracy of the eye and the inbuilt processing assumptions of the brain.

    As anyone who has watched tube lighting in a nightclub can attest, whenever two or more static flashes occur within close spatial and temporal proximity, the eye interprets this as movement. This is called the 'phi' phenomenon. It is this phenomenon that underpins cinema, TV and so on.

    Actually, I suddenly realise that explaining why most of what we think about what our watches are doing comes down to our design rather than the design of watches is a bit more of a chore than I would enjoy writing and you would enjoy reading.

    Anyone who is really interested, the American philosopher Daniel Dennett's book 'Consciousness Explained' has a good section on this sort of stuff - even if he never quite gets round to really explaining consciousness!

    Anyone who isn't really interested - I reckon mechanical watches are far more precise instruments than we are. We are a great big bag of bodges while they are designed properly. In that sort of time scale we cannot be trusted - digital watches however are within our accuracy range.

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    Member Bruce Reding's Avatar
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    Re: Yeah but those one second ticks that don't line up...

    Quote Originally Posted by artec View Post
    Don't you think most of the current high-tech timing devices used in various sports that need accurate timing would be using digital read-outs today...... and for the last few years? I'm sure Formula 1 racing does, for example.
    Absolutely. I was referring to pre-electronic days. Top international track meets timed races to the tenth of a second long before electronics. At that level, this kind of error would have made a difference.
    Last edited by Bruce Reding; March 8th, 2007 at 03:54.

  10. #9
    Member Bruce Reding's Avatar
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    Re: Yeah but those one second ticks that don't line up...

    Quote Originally Posted by lysanderxiii View Post
    That's the reason why those official timers were a few thousand (in 1970's) dollars apiece.

    But, the biggest error in that type of timer is the human element; the average person's reaction time ia around 0.3-0.5 seconds.
    Those would be interesting to collect. The ones in the Omegamania auction have estimates that are quite high.

    Of course, you're right that the human user's reactions constitute a significant error source. Still, if I was the one specifying the performance of the watches, I'd want this human element to be the dominant error source. As such, I'd specify the watch such that its errors were significantly less. I suspect that the random errors, such as variability in the seconds hand misalignment, add in a root mean square way. (As opposed to rate error, which would be a pure linear effect.) Therefore, if the human can do 0.3 seconds at best, I might want all other errors to be below 0.15 seconds. Therefore, I might want the error due to this seconds hand alignment to be 0.1 seconds at most. This would constitute a challenge in making the timepiece. (And, of course, getting the rms sum of all the errors in the watch to below 0.15 seconds would be a real challenge too, especially for longer races such as the mile, where the rate error becomes significant as well.)
    Last edited by Bruce Reding; March 8th, 2007 at 03:50.

  11. #10
    Member lysanderxiii's Avatar
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    Re: Yeah but those one second ticks that don't line up...

    Quote Originally Posted by Bruce Reding View Post
    Those would be interesting to collect. The ones in the Omegamania auction have estimates that are quite high.

    Of course, you're right that the human user's reactions constitute a significant error source. Still, if I was the one specifying the performance of the watches, I'd want this human element to be the dominant error source. As such, I'd specify the watch such that its errors were significantly less. I suspect that the random errors, such as variability in the seconds hand misalignment, add in a root mean square way. (As opposed to rate error, which would be a pure linear effect.) Therefore, if the human can do 0.3 seconds at best, I might want all other errors to be below 0.15 seconds. Therefore, I might want the error due to this seconds hand alignment to be 0.1 seconds at most. This would constitute a challenge in making the timepiece. (And, of course, getting the rms sum of all the errors in the watch to below 0.15 seconds would be a real challenge too, especially for longer races such as the mile, where the rate error becomes significant as well.)
    Those stop watches have very big dials. Around 3 inches in diameter.

    The amount of misalignment of the tip of the hand (due to an off-center axis) is always twice the error of the of the centers. So the bigger the dial the less the amount the tip will be from the correct tick mark, given the same center misalignment.

    If you can hold the tip error misalignment to one third the smallest tick mark spacing (or hold the center axis misalignment to one-sixth the tick mark spacing) the operator will be able to read the time accurately even though it does have an error.

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