I don't know if it is exact but monday i made 2 video clips and the watch was -0,275 s (mean), today again 5 clips -0,267 s, sorry 0,008 s
Longines VHP accuracy
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Unless you have a super camera the best accuracy you can get with the video method is 1/25=0.04s. Having said that it's good that you're not seeing any drift. When it's that close I generally run a couple of tests to see where the "tick" falls, it could be anywhere in that 0.04s range.
Actually more like 1/30s if the camera and the LCD are not that great, but if the LCD is bright and you have a very strong light on the watch itself you can go to the limit from the LCD, which is 1/60 - the camera still stays at 30 fps but since the exposure time is (much) shorter than 1/30 you tend to get only one LCD frame (or something like 80% of it and 20% of the next/previous).
The other thing is that you can also look after a number of frames and do some average, and with a very careful analysis and some care on internet sync you can sometimes get to around 0.005s accuracy (which I believe can be seen in the first 2-months results on my 8F33 (not my 8F56), where the standard deviation was suggesting an error in that range or better).
I adjusted my VHP on 15/3/2010 with 23 taps and today it shows +2,3 spy, on-wrist, I guess it works
sad I had to reset my 8F32 for summer time, it was -24 spy from 29/1/2010
I will leave it until next DST change, on and off, and then maybe try pattern cutting (not very sure about that though)
sad I had to reset my 8F32 for summer time, it was -24 spy from 29/1/2010
I will leave it until next DST change, on and off, and then maybe try pattern cutting (not very sure about that though)
Nice work. Mine is now at +5.1spy when worn 24 hours a day. I'm going to see how it behaves at room temp and see if it needs further adjusting.
By the way, unless you have a clever setup and are relying on holding two needles with one hand and tapping with another one with your other hand, I've found that setting the day to 1 helps as you don't have to wait for the calendar wheel to turn. You can check that the watch got properly powered in the process by looking at the seconds hand before and after.
By the way, unless you have a clever setup and are relying on holding two needles with one hand and tapping with another one with your other hand, I've found that setting the day to 1 helps as you don't have to wait for the calendar wheel to turn. You can check that the watch got properly powered in the process by looking at the seconds hand before and after.
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Well done both of you!
Some good tricks there.
The shirt button and starting off with a date of one.
Almost makes me want to do it again.
Almost.
|>
Some good tricks there.
The shirt button and starting off with a date of one.
Almost makes me want to do it again.
Almost.
|>
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Good jobs at having the coordination to do that adjustment.
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A beautiful shirt buttons:-d
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Needles, buttons, what's next?
:-d
Transparent buttons would be even better.
If we have to believe the high aging numbers, another calibration is due any minute!
:-d
Transparent buttons would be even better.
If we have to believe the high aging numbers, another calibration is due any minute!
Good news, my Aerospace went back to normal after I changed the battery (tiny screws, not easy!). Still interested in the steps if anyone figured them out.
I'm sure I saw another post of yours recently were you gave the time in spy...but can't find it again, even after a good hour of searching! Anyway I was wondering if you'd seen any changes in the drift over time (the so-called "aging") with your elaborate setup? It must be there since many of the TC watches that fall into the hands of the crazy bunch here are often way out of spec.
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It is measured every day and when its too far ahead I leave it off overnight to slow it down a bit. That way it stays around 10 ms from perfect.
That way I can't keep track of the rate though.
If there was any aging I would only notice that if I mostly needed to leave it off overnight or something like that. Nothing like that has happened so far. The temperature effects are far too large to notice the tiny aging if in fact it did exist.
It really needs a very elaborate temperature setup like dwjquest's one to ensure you measure in the same environment from one year to the next.
As in: one needs to be ridiculously sure that the 22.0 degrees now is the 22.0 degrees you had last year.
That is quite a challenge to get right. I guess I'd rather let dwjquest do the hard work!
Nice strategy! Maybe you can't keep track of the rate "scientifically" but it does show that there is no significant impact of "aging" plus at the end of the day what matters is the "real life" ;-) Still I wonder how all these TC ETAs got to be so much out of spec in terms of their drift at 50+ spy.
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The quartz literature all mention aging. But the aging stabilizes to a constant rate after certain period. I guess the movement must compensate for that constant rate.
With these quoted values being so high, its effect should have shown in the watch performance already.
Personally I put the bad initial performance down to the lack of calibration. Looks to me like that step was left out altogether. :think:
I believe that I have seen very often references that the 32 kHz aging becomes very small after a few years, but certainly on higher frequency high-accuracy OCXO the manufacturers provide very clear aging numbers for like 10+ years!
Not strictly speaking "Longines VHP accuracy" since it's Omega's rating of the Omega 1690, the same TC ETA 252.611 movement as the one used in the Longines VHP (minus the 3v battery so it's much easier to adjust it!) and they're on the conservative it seems with a +/- 055 spd rating, i.e. +/- 20spy.
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Not very ambitious since testing here shows a variation of about 10spy between room and warm temperatures...but a good way to prevent accuracy fans (who don't know how to adjust it themselves) to ask for any adjustments.
So far we had :
- ETA's technical documents (https://secure.eta.ch/CSP/DesktopDefault.aspx?tabindex=2&tabid=28 and type 252.611) to go buy and they only recommended the rate be adjusted if the watch drifted more than 0.8 seconds over a month of testing, i.e; 10 spy, the implied rating
- Breitling rating their "Superquartz" at +/-15spm, a bit less conservative (not sure if it's stated in the manual).
Not very ambitious since testing here shows a variation of about 10spy between room and warm temperatures...but a good way to prevent accuracy fans (who don't know how to adjust it themselves) to ask for any adjustments.
So far we had :
- ETA's technical documents (https://secure.eta.ch/CSP/DesktopDefault.aspx?tabindex=2&tabid=28 and type 252.611) to go buy and they only recommended the rate be adjusted if the watch drifted more than 0.8 seconds over a month of testing, i.e; 10 spy, the implied rating
- Breitling rating their "Superquartz" at +/-15spm, a bit less conservative (not sure if it's stated in the manual).
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As an electrician I would recommend to do that in slightly different way: connect a wire (or needle on the wire) to 'C+' or 'C-' terminal; tap to the '+' of the battery. It's easier to hold steady connection on small 'C' terminal while tapping the large '+' battery area and it also doesn't scratch golden PCB pad of the movement ;-).
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My VHP 200m has been on display for a few years. Over the last 12 months it absolutely astonished me by staying on the correct second ! So much so I started wearing it again, and of course it started to run fast (roughly +6spy), so out came the perspex disc and wires. There's zero feedback so not sure my attempted one impulse on C- was good. ...time will tell.
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