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Discussion Starter · #1 ·
Ok ..there's been loads of debate of Sellita SW200 clone of the now much regarded ETA 2824-2, mostly about reliability & quality issues...but what about accuracy?

As far as i can see, the SW200 has 26 Jewels as opposed to 25 J in the ETA and most enthusiasts would argue the better finish maybe of the ETA movement.

So, as i've got the opportunity to test the SW200 in my new titanium cased TAWATEC , i decided to test the watch non stop over a 1 month period in real time-so that meant wearing to work, to bed, in the bath, hiking- basically getting as much field testing as possible in a range of temperatures, atmospheric changes & environments...[ its quite annoying having to wear the same watch constantly but this would be the best test ]
I would check the watch the same time at mid -day against an atomic clock. After a good shake out of the box, we began.

Day 1 & 2, the watch was +4 secs/ each day but started to settle down and after 8 days the watch was +23 secs fast [ average 2.875 sec p/day ]

After the next 7 days the watch had gained a further +10 secs [ average 1.428 sec/day ]

In the 3rd week the watch had gained +3 sec [ average 0.428 sec/day ] The TOTAL so far +26 secs

I couln't be more pleased. It had settled down nicely.

For the 4th week, even i couln'd have expected this and over the next 8 days, there was a - 1 sec gain over two days and then a + 1 sec gain over 2 days. The other days were +/-0

So for the 8 days the net average was +/- 0 secs/day..........!!

Quite superb....incredible infact for a mechanical movement of wheels & springs..

I took the watch off.. and left it for 2 days [ had to wear something else !!] and left it face up.
In this time it had gained +7 secs [ obviously doesn't like this position]
Also it would seem the movement likes constant movement to be accurate.[ must get a winder]
But quite frankly, none of my other watches are as accurate as this movement.:-!

So....maybe i'm just lucky with this one. ;-)..what's your experience.?
 

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My understanding is that Sellita would assemble and finish movements for ETA so the movements and their quality are essentially identical. I don't remember the exact number but the Sellita that I used to own ran about 3 seconds fast over 24 hours.
 

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Try to do the power reserve test. Put the watch dial up wherever, wind it fully, then measure every 24 (I prefer 12) hour increment. This test gives a lot of useful data. I've owned watches that were basically +0/day on wrist, but would gain 10 seconds over their 45 hour PR test. Plus it lets you know exactly what your PR is. Really stable movements have little deviation from on the wrist to off the wrist, which is the goal.
 

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I think you are really lucky that the watch seems perfectly regulated for your wearing habits (and activity level).
An interesting test would be to not wear it and time it for 24 hours in each position (dial up, dial down, crown up, left, right and crown down). Winding and timing always at the same time of the day. Ideally the values would all be relatively close together.
Measuring the power reserve, and timing during the second half of it, as suggested above, would also be interesting. Essentially you would be recreating part of the COSC tests. If your watch passes, you get to print your own certificate...:-d
 

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Yeah, I've found the power reserve test to be the place that really separates movements. I actually see a lot of $100-$200 Orients that are really accurate on the wrist for example, but are pretty bad off of it in the power reserve test (which isn't an attack on Orient, their accuracy is superb for the price). I'm sure this movement will do better than those of course, but it'd be nice to know how it compared to my 8500 or 9S85 etc.
 

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Discussion Starter · #8 ·
I think you are really lucky that the watch seems perfectly regulated for your wearing habits (and activity level).
An interesting test would be to not wear it and time it for 24 hours in each position (dial up, dial down, crown up, left, right and crown down). Winding and timing always at the same time of the day. Ideally the values would all be relatively close together.
Measuring the power reserve, and timing during the second half of it, as suggested above, would also be interesting. Essentially you would be recreating part of the COSC tests. If your watch passes, you get to print your own certificate...:-d
Thanks for all the replies. Well here are the tests for a total of 48hrs -mini test.
9am-9pm [ crown up ] + 1 sec
9pm-9am [ crown down] + 2sec
9pm-9am [ face down] +4 secs
9am-9pm [ face up] +3 sec

Would this be classed as COSC

I guess this isn't too bad. So off the wrist- i will keep it crown up / or invest in a tidy watch winder....
Very similar to my Seiko OM with 7s26 21J movement- best results with crown up off the wrist as well
At the end of the day- so long as its accurate on the wrist for a daily wearer- that's what counts for me.....
Cheers ...Pete
 

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Thanks for all the replies. Well here are the tests for a total of 48hrs -mini test.
9am-9pm [ crown up ] + 1 sec
9pm-9am [ crown down] + 2sec
9pm-9am [ face down] +4 secs
9am-9pm [ face up] +3 sec
That's pretty amazing.
Would this be classed as COSC
According to the COSC web site, a movement not tested at COSC can never be COSC, no matter how good... I don't even think you could give them money; the movement has to be submitted by the manufacturer (or assembler, in case of those 'manufacturers' that reuse ETA movements).

I see two alternatives: a) send me hundred bucks, and I grant you a license to call your movement LCOSC (LCheapo-OSC) ;-) ,
or b): keep your hundred bucks, and start your own certification scheme :-d
I think before COSC astronomical observatories used to do this, and they even had competitions and all that.
Apropos competition: Over on the NAWCC forum they occasionally have competitions (one month without resetting), but I'm not sure whether they do that for modern wrist watches. I guess you could start a competition here?
 

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"Can never be COSC", I don't think that JLC fans are going to lose much sleep over that.
That's pretty amazing.

According to the COSC web site, a movement not tested at COSC can never be COSC, no matter how good... I don't even think you could give them money; the movement has to be submitted by the manufacturer (or assembler, in case of those 'manufacturers' that reuse ETA movements).

I see two alternatives: a) send me hundred bucks, and I grant you a license to call your movement LCOSC (LCheapo-OSC) ;-) ,
or b): keep your hundred bucks, and start your own certification scheme :-d
I think before COSC astronomical observatories used to do this, and they even had competitions and all that.
 

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Well, there are various chronometer standards, as you mention, there's a German one and a Japanese one (both of which are more restrictive, as an interesting aside). And then even within Switzerland there are others. There used to be an observatory standard. Then there's various "seals" that watchmakers like Patek use to certify their own movements.

The nice thing about COSC, as compared to Grand Seiko, Patek or JLC is that it's at least theoretically independent. Of course, those latter brands all have enough street cred that it doesn't actually make a difference to the public, but it's not to say that at some dark day in the future they couldn't lower their standards for their own watches.

It is technically true that your watch cannot be COSC if it didn't pass COSC literally in a COSC facility. Grand Seikos aren't COSC even if they're +4/-2 Seiko rated, as some are. Thus, you can still be COSC spec.

But remember, that test is 5 positions, two temperatures and isochronism. When most people declare their non-COSC watch is COSC, they're unknowningly making a much narrower claim. Basically, to pass COSC, or GS (etc) it has to meet or beat the standard in the worst case scenario, which we don't know until we actually test all the scenarios. For GS, it's even worse, since it's 6 positions, 3 temperatures and a tighter range.
 

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I personally have had good experience with the SW200 (had it in a Imperious/Invicta once) and the accuracy was BETTER than my Hamilton with ETA28XX. I don't own either watches now and I don't have any particular preference with either movements. I think both are excellent movements and pretty much identical in terms of performance/accuracy.
 

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Discussion Starter · #16 ·
48 hours of power reserve, or 24 hours from fully wound (per position)? It'd be pretty impressive if the S200 got 48 hours of power reserve.
Yes, i did give a shake every 12 hrs when i put into a new position as one of the members posted suggested earlier.
I will do the power reserve test [PR] without shaking to test the power reserve and post results.....
 

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Well, there are various chronometer standards, as you mention, there's a German one and a Japanese one (both of which are more restrictive, as an interesting aside). And then even within Switzerland there are others. There used to be an observatory standard. Then there's various "seals" that watchmakers like Patek use to certify their own movements.
The German standard for for spring balance oscillator timed chronometers is not more restrictive than ISO 3159. In fact, the requirements are exactly the same as ISO 3159.

DIN 8319, the German standard for chronometers is divided into two parts:

DIN 8319-1, Part 1 - Wrist Chronometers with Frequency Oscillating Systems < or = 1000 Hz,
DIN 8319-2, Part 2 - Wrist Chronometers with Piezo-Electric Oscillating Systems

It is often stated that the German standard is more restrictive, however, this is incorrect. The German standard, unlike the ISO 3159 (International), BSI 3159 (British), TSE 3159 (Turkish) or CNIS 4032-83 (Chinese) chronometer standards includes the testing of quartz chronometers. It is actually more liberal, because, according to the Germans, there is a whole class of chronometer possible. All of the existing chronometer standards that I have seen (the above mentioned) have the same requirements for the chronometer classification.

The Japanese Standards Association (JSA), no longer maintains a chronometer standards, as there is no longer an independant body to test chronometers.
 

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I use chronometer standards to indicate the internal testing of these brands that meet or exceed COSC, as I point out with Patek.

The German standard is actually not the Swiss standard, as they test cased movements instead of uncased.

Mainly, I object to the COSC's "independence" insofar as, if it is independent, it is not unbiased, in that all non-51% or above Swiss watches automatically fail the first test.

Many brands have taken the higher road and use more stringent internal testing, like JLC and Patek, and Nomos for the Germans. Seiko, of course, was a Swiss certified chronometer prior to being banned for its racial origin.



This was certified by the Basel Observatory Standard which was a measurement not inherently designed to promote one nation's products.
 

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The German standard is actually not the Swiss standard, as they test cased movements instead of uncased.[1]

Mainly, I object to the COSC's "independence" insofar as, if it is independent, it is not unbiased, in that all non-51% or above Swiss watches automatically fail the first test.[2]
1) Yes, the German Standard is the same as the International Standard, ie, ISO 3159, and COSC tests to ISO 3159. ISO 3159 states:
[paragraph] 3.2 The term "Chronometer" is applied to precision wristwatches regulated for different positions and for various conditions of use. Conformity to the definition of Chronometer will be certified by a neutral official authority, which checks the watch, or if necessary the movement, and issues an official certificate.
The standard gives the certifying body the option of testing the entire watch or just the movement. COSC certifies about 1.2 million movements a year, that's over 3000 each day, or 50,000 in each 15 day batch. In order to process that many watches or movements requires automation. Back in the seventies when they started to automate the process it was found (and still is, as it reduces errors) that common hands and dials are necessary.*

2) COSC is Contrôle Officiel Suisse des Chronomètres, the "neutral authory" in Switzerland. The "neutral authority" in Germany is the German Calibration Service in the old "Urania" observatory of Glashütte. (Swiss watches would be turned away from Glashütte....) Both Glashütte and COSC are independent from the movement manufacturers. Other countries are welcome to create their own independent neutral test body...

* The method use to test the movements:
1. the manufacturer must supply the movement with a plain white dial with black markings, plain black stick hands and in plastic cases of certain dimensions with a clear lid.
2. the movements are wound by machine and placed inn a large tray, where an optical reader photographs each movement, after which the tray is placed in the appropriate position (CH, 6H, etc)
3. after 24 hours the tray is removed and each movement is re-photographed. The two images are compared and the displayed lapsed time is calculated to the second.
4. the process is repeated for 15 days.

Glashütte is without automation and this limits the volume of chronometers they can process a year. You can bet if the German watch industry starts to produce chronometer grade watches at a volume approaching the Swiss, Glashütte will start to require similar "movement only" rules.

It should be noted that back in the late sixties and early seventies Japan also had an independent chronometer certification facility, however, the volume of chronometer send for testing was too low to make the facility profitable. Remember the test facility was a business, just like any other.
 

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The German chronometer standard is different, contrary to your claim. It tests cased movements. I make no claims at to why, only that it is different, and to most people, that is a tougher standard (cased versus uncased). So there you go. Different.

You're right that Japan had a chronometer standard, but you seem to ignore the fact, as I pointed out, that Seiko was Swiss chronometer certified from 1964 onward. There's a photo of a Swiss certified GS above.

The COSC is not an unbiased examiner. It judges watches based on racial, ethnic or national origin (depending on how you look at it) which has no objective merit whatsoever, particularly as Japanese watches were easily defeating the Swiss competition, GP aside, by 1968. That's not a coincidence, of course.

So, conclusions:

The German Chronometer standard is NOT the Swiss COSC in a relevant way.
Seiko was Swiss chronometer certified until being banned from competition and thereafter.
The internal standards of Nomos, Grand Seiko, JLC and Patek are basically comparable in terms of testing and, for all intents and purposes, passing their internal standards yields a chronometer grade watch (except better).
COSC is not an unbiased resource and was not created to find truth in movement making but to push a national industrial objective.
 
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