Tolerances depend on the manufacturer. I don't think Mido advertises an accuracy tolerance for non-chronometers, though I'd expect a tolerance of +/-20 spd. A non-chronometer could end up just as accurate as the chronometer despite the looser tolerances.

 

Thanks, so same movement system doesn't mean similar accuracy.

 

Not in the slightest, tbh. For non chronometer, typically non (factory)regulated movements, luck of the draw comes in to play quite a bit. One guys watch may run at +1spd, the next guys watch, which was built right after the first guys, may run at +20.

 

I owned that watch in a white dial. The powermatic 80s are extremely accurate. No need to worry.

 

Nice, the multifort power reverse (not COSC) is cooler than the chronometer1 for me, I just worry about accuracy, 20-30 sec x day is a lot
Is possible to empirically check the accuracy? For example comparing the watch accuracy with a synchronized clock after 24h or is a non-sense test?

 

With respect to the two Midos at hand:

1) The Multifort Power Reserve has a date aperture and uses the Automatic Mido Caliber 80 (base ETA C07.671); and, the Multifort Chronometer 1 has a day and date aperture and uses the Automatic Mido Caliber 80 COSC Si (base ETA C07.821).

2) Both movements are extremely accurate and precise in a controlled environment/setting - outside of a controlled environment/setting may be a different matter.

However, in the case of the Caliber 80 COSC Si, you have an additional assurance its accuracy and precision will not be affected in a controlled environment/setting with temperatures ranging from 8°C to 38°C (note: 8°C is not very cold BTW). Plus, its accuracy and precision will be less affected by magnetism because of its silicon balance-spring.

3) Note, the best guesstimate for most ETA C07.XXX movements would around -4/+6 spd in a controlled environment setting. While a COSC certified C07.XXX will provide additional assurance of operating within COSC specifications.

 

Thanks a lot, very useful!

 

I once had a TagHeuer WAN2110 that ran +15 spd. In spec for the watch, but drove me crazy, especially with a screw down crown.

Now, if I buy a watch with a screw down crown, it will only be COSC or equivalent certification.

For non-screw down crown, I’m ok with looser accuracy.

Cheers!


Sent from my iPhone using Tapatalk

 

I would expect +- 20 SPD at the worst though it may be much better than that. If you opt for the chronometer it WILL run to COSC specs but if you opt for the non chronometer it MAY run to COSC specs (then again it may not) as it only needs to meet the stated variances set by the manufacturer.

 

here I usually have more problem with hot than cold
At the end I think I will buy the not COSC, check it and if it will be an unlucky one I will give it back and buy the chronometer instead.

 

The Powermatic 80 non-COSC in my Mido Ocean Star GMT is currently running about +2 per day. Unless you need chronometer accuracy or just have a COSC fetish, the extra outlay for a COSC certified movement is completely unnecessary, especially with the newer Powermatics.

 

The Caliber 80 movements aren't regulated by a simple screw like the 2824 movements. It's done via screws on the balance wheel. I don't know, but this may affect the ease of finding someone to do it as well as the associated cost.

 

This. While the movement can be regulated (contrary to myths you see circulating about), it's not quite as simple as the older movements with etachron regulators. A legit watchmaker, someone with experience regulating Rolexes or Omegas would have the know-how, though it might require some special tools. It also might require some level of disassembly of the movement, which will make for a costlier task.

 

The unregulated ETA powermatic 80 in my Certina dive watch runs about +8 daily, small variations for temperature.

COSC if you’re a stickler for extreme accuracy - or get a watch with ETA’s high accuracy quartz movement, they’re not expensive.

 

This is from the article mentioned by @plohmann: The main targets were to improve the power reserve and reduce the manual work to ensure accuracy and stability by industrial processes. It goes on to say: The spokesperson told me, "The forks and that way the connected inaccuracy, especially at low power reserve, for fine adjustment have been removed. The whole design allows direct and automatic production of the whole regulation group without manual operations." This is no less than a silent revolution in watchmaking, done with the most modern techniques. In fact, the entire idea of having an escapement with no regulator has been replaced by setting the rate with a laser in the factory.

I interpret that as saying the fork with the regulation screw (regulator system) on the 2824 has been removed and that the entire system can now be produced and set by machine (without manual operations). The rate is set with the help of a laser, not by a laser. Omega, and other typically more expensive brands, use the same type of system (free-sprung balance wheel) for some of the same reasons mentioned above re: low power...also shock resistance.

Monochrome (to be consistent) had previously put out an article addressing what they call the regulating organ (A Complete Guide to the Regulating Organ - Monochrome Watches). About 1/2-way down the page it talks about the free-sprung balance wheel. From the article: Watches without regulators are called free-sprung. The spring is not held by regulator pins and has a constant length. To adjust their rate, instead of working on the spring length, watchmakers work with the inertia of the balance wheel, moving the screws or weights positioned on the balance.

This is what's being done in the previously provided videos. The adjustment screws are even visible in the pictures Monochrome shows in the article talking specifically about the Caliber 80 movement.

Everyone can feel free to interpret any of this as they see fit, but I tend to go with the Powermatic 80 movement can be "regulated" or otherwise have their rates adjusted.

edit: fixed typo