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Eco Drive Accuracy Report...

15907 Views 16 Replies 7 Participants Last post by  Fastest
...mostly anyway. After gaining a fair few Citizen Eco Drives during the past year or so, i set them all to atomic time at the beginning of the year and have kept tabs on how they've performed purely for my own amusement.

I thought id share the results with the members here and invite others to let us know how their eco drives have been performing. Maybe we can get a fair idea how these movements perform if we get a large enough database. Obviously all radio controlled models should be excluded from this, (even though two of mine are rc, as im in oz, none receive any signals and thus only operate as standard quartz).

my rate results (all watches except where noted set on 28/1/10):

Citizen AS8009-53E = +4sec/month

Citizen Calibre 2100 = -2sec/month

Citizen Nighthawk = +4sec/month

Citizen World Time = +6sec/month

Citizen BJ2120-07E = +8sec/month

Citizen BN0065-55E = +8sec/month

Citizen JP3040-59E = +3sec/month (digital display)
(battery powered) = -5sec/month (analogue display)

Citizen PMD56-2972 = +/- 0sec/month (measured 2wks only)

Citizen JR3090-58M = +4sec/month

Citizen BL5280-52W = +9sec/month

and as a reference from two others i measured:

Casio EF-524SP-1A = +10sec/month (measured 2 wks only)

Tissot T-Touch = +2sec/month

I hope this was of interest to someone
...surprised?, as expected?, let us know what you guys are getting.
This is my first post here, i see many regulars from other joints ^-^ , pleased to be here, thanks for the invite John, cheers.
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Those are the sort of figures I'd expect to see, well within Citizen's specs. Since the specs are based on the watch being worn for about 16 hours a day at normal temperatures, you might find the ones running fast will improve their performance if you wear them daily. [Edit -- actually, I got that the wrong way around. Non-thermo compensated quartz watches tend to go faster when warmer, such as when being worn. This is the opposite to mechanical watches, which tend to run slower when warmer.]

One thing that did surprise me was that the digital and analogue on your JP3040 drift apart -- and in opposite directions. Mine stay firmly in sync, as does my other Aquamount and also my Aqualands.
brett said:
Gday Sir Les,

thats interesting to know about the 16hr wear/day spec on quartz, has that been published by the manufacturers or accepted wisdom based on experience? also interesting to know quartz slow down while worn more, but i guess that'd tie in with your first point mentioned?
Actually, I got the 'quartz slowing down when worn' thing the wrong way around -- sorry about that! In contrast to mechanical watches, quartz tends to run faster when being worn, due to the warmth from contact with your skin.

Typical Citizen quartz accuracy specs are +/- 20 seconds/month when worn at normal temperatures of +5°C to +35°C (41°F to 95°F). Wearing the watch on a daily basis tends to keep its temperature constant, and hence stabilise its timekeeping. Eco-drives tend to be more tightly specified to +/- 15 seconds/month, although I must say I've found from personal experience that they run much more accurately than that, even when not being worn. The ones I have range from 5 sec/month to less than a second a year. Sometimes you get lucky! :)
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