Thinking About Watch Accuracy and Regulation

[Chiboy]

I really don't understand how watches work, or why watches are accurate or not. But here's my theory about regulating a watch, and those who know more than me (ok, all of you), tell me if I am on the right track.

I have read the numerous posts about Rolex guaranteeing watch accuracy in a sterile environment, without being worn, perhaps not even in a case, etc., and it seems to me that if a watch is consistent, then it can be made accurate through regulation. Since some people are more active than others, wear their watches more or less hours in a day, and numerous other factors, it is impossible for Rolex (or any other manufacturer) to produce a watch that will be super accurate (say, within 1 s/d) without knowing the ultimate wearer and his habits. But, if you are one who tracks his watch's accuracy, you can tell a good watch repair person that your watch is gaining/(losing) x seconds per day, and they can tweak the settings to get the watch very close to dead accurate, as long as you continue to wear the watch as you were, remain about as active as you were, store it overnight the same way, etc.

Is that true? I know some here don't care at all about this and some care a lot. If you rotate watches all the time and are setting your watch every day as you strap on a different one, I can imagine you wouldn't know or care how accurate it was, because it only has to keep good time for 16 hours (or whatever). But if you wear your watch every day, and it is only off half a minute in a month, you might find that amazing.

[douglasf13]

You’re talking about precision vs. accuracy, and, yes, a precise watch can be regulated to be pretty accurate. That being said, it’s still hard to predict how the watch will react to an individual. A watchmaker at F.P. Journe once told me it’s relatively easy to get a watch to run within 2 seconds on a person, but it gets exponentially harder once you cross that threshold. There must be a little luck involved.

What’s weird for me is that my last 3 Rolex/Tudors have run about the same.

[Why1504]

I am 59 and have worn mechanical watches for most of my life. My Rolex that is less than a week old has tracked to let than a second a day out of the box. I have never had a watch do this before. They have always run fast....

[peterpl]

Originally Posted by Why1504

I am 59 and have worn mechanical watches for most of my life. My Rolex that is less than a week old has tracked to let than a second a day out of the box. I have never had a watch do this before. They have always run fast....

All my Rolex's are slow as well. GMT2c, Sub-C, DD40, Skydweller and DJ41 all ran slow with my GMT2c the worst at -4s a day.

The rest of them are either -1s or -2s a day.

[Widows Son]

All my watches are far more accurate than they need to be. Rarely do I have to coordinate a lunar landing or plan a bombing raid. If +/- a few seconds a day is really that important in your life, I'd suggest a quartz watch or a smart phone.

[RRGHOST1]

I wouldn't worry if my watch was 1 minute out a day to be honest, I am not that bothered, just adjust accordingly and just marvel in the fact that it is mechanical and they can adjust it to the accuracy that they can do.

[tamiya]

Originally Posted by Chiboy

Since some people are more active than others, wear their watches more or less hours in a day, and numerous other factors, it is impossible for Rolex (or any other manufacturer) to produce a watch that will be super accurate (say, within 1 s/d) without knowing the ultimate wearer and his habits. But, if you are one who tracks his watch's accuracy, you can tell a good watch repair person that your watch is gaining/(losing) x seconds per day, and they can tweak the settings to get the watch very close to dead accurate, as long as you continue to wear the watch as you were, remain about as active as you were, store it overnight the same way, etc.

Is that true?

I've been wondering same... it would be great to be able to record how much time/24hrs the watch spends at various positions (& associated deviations from reference timekeeping) then the watchmaker can adjust accordingly.( I was even wondering how to build a portable timegrapher that could clip onto the watch whilst it's worn & log data for 24hrs.)

But merely peeking inside the design of most nothing-fancy utilitarian movements, afaik there's no ability to adjust individually for the different positions a chrono is timed at. Nothing where you can stick a spanner in to adjust afaik... it's only that one balance wheel that keeps the beat.

Hence innovations such as turbillons were invented, constantly rotating cage for balance wheel to live in that zeros out the effects of gravity on timekeeping.


But definitely if your usage pattern results in a constant deviance say +2mins/day then it's no problem to adjust to account for that. But the if you leave watch running stationary for a day then wil it run -2mins?

Personally for my wearing pattern, don't see that much accuracy deviance between left-on-desk vs wearing. So I just aim for +/-0 on the bench.

I'm a pretty sedentary bear though.

[SDRider]

AFAIK activity level of the wearer has nothing to do with the accuracy of the watch and Rolex does certify their watches after casing. Mine is slow about 1/2 second per day and has been since I bought it. It loses about 3-4 seconds per week and I wear it almost constantly but I haven’t found it to be less accurate when I haven’t worn it or when I’ve been more active either.

Wearing the watch only winds it.

[Andad]

Let's keep researching.

Wearing patten has an effect on precision.

[DavidUK]

My DJ41 is gaining 1/2 second a week since purchase in August, which is pretty amazing compared to the 8 seconds a day of my previous DJ36 16233.

But more amazing is my wife's DJ31. Checking it after 10 weeks daily wear from new it was accurate to the second. A little frustrating for me as the DJ41 movement is supposed to be superior?

In the end I guess it's all down to the luck of the draw with a new watch.

[tamiya]

Originally Posted by SDRider

Wearing the watch only winds it.

you probably have newer models but the oldies I play with, mine are spot-on or fast when fully wound for their first 24hrs. Second half of reserve if not woundup they start losing time. Achieving +/-0 on the bench by surfing the winding reserve after 24hrs.

yeah I'm a geek

[brandrea]

I switch out every 2-3 days so accuracy isn't on my radar

[beshannon]

Originally Posted by Chiboy

I really don't understand how watches work, or why watches are accurate or not.

Here you go

https://en.wikipedia.org/wiki/Mechanical_watch

[Rebel]

Originally Posted by Widows Son

All my watches are far more accurate than they need to be. Rarely do I have to coordinate a lunar landing or plan a bombing raid. If +/- a few seconds a day is really that important in your life, I'd suggest a quartz watch or a smart phone.

Exactly.

[HONDABBQ]

For the last 3 months my 6 month old Z Blue runs a consistent +6 seconds every 2 weeks. Its weird/magical how accurate it is with my regular daily routine.

[RichardF]

Originally Posted by Chiboy

I really don't understand how watches work, or why watches are accurate or not. But here's my theory about regulating a watch, and those who know more than me (ok, all of you), tell me if I am on the right track.

I have read the numerous posts about Rolex guaranteeing watch accuracy in a sterile environment, without being worn, perhaps not even in a case, etc., and it seems to me that if a watch is consistent, then it can be made accurate through regulation. Since some people are more active than others, wear their watches more or less hours in a day, and numerous other factors, it is impossible for Rolex (or any other manufacturer) to produce a watch that will be super accurate (say, within 1 s/d) without knowing the ultimate wearer and his habits. But, if you are one who tracks his watch's accuracy, you can tell a good watch repair person that your watch is gaining/(losing) x seconds per day, and they can tweak the settings to get the watch very close to dead accurate, as long as you continue to wear the watch as you were, remain about as active as you were, store it overnight the same way, etc.

Is that true? I know some here don't care at all about this and some care a lot. If you rotate watches all the time and are setting your watch every day as you strap on a different one, I can imagine you wouldn't know or care how accurate it was, because it only has to keep good time for 16 hours (or whatever). But if you wear your watch every day, and it is only off half a minute in a month, you might find that amazing.

The Rolex watch models that are certified chronometers are some of the most accurate watches in the world. They were known for running out of the box around 6 seconds a day fast some years ago and could easily be regulated to run slower. Now they are set to run around + or- 2 sec a day. There are many things that can slow a watch down and affect its accuracy such as extremes in temperature, positions, movement, wearing during sports, electromagnetic fields, how close the Rolex is to needing service and or its previous service history over the years, etc. A Rolex can be regulated to very close timing tolerances. My Rolex Explorer II A serial was recently serviced and has been regulated to gain of 1 sec or less per day and I and am pretty active person plus i sleep in my watches. Other Rolex watches I have owned over the years I had regulated to gain of approximately +2 secs a day without a problem. I generally like mine to time that way. I have worn both a Sub and an Explorer II in the Middle East and had them both exposed to very high temperatures in the desert and never had any problems with their timing.

[Chiboy]

Originally Posted by Widows Son

All my watches are far more accurate than they need to be. Rarely do I have to coordinate a lunar landing or plan a bombing raid. If +/- a few seconds a day is really that important in your life, I'd suggest a quartz watch or a smart phone.

If making snarky comments on a message board is really that important to your life, perhaps you can tell me where in my post I suggested that accuracy was so important in MY life. Given that this board is devoted to discussing WATCHES, I thought I would try to learn something about how Rolex makes WATCHES run to such tight tolerances.

[Chiboy]

Originally Posted by beshannon

Here you go

https://en.wikipedia.org/wiki/Mechanical_watch

Thanks. Will read this.

[Widows Son]

Originally Posted by Chiboy

If making snarky comments on a message board is really that important to your life, perhaps you can tell me where in my post I suggested that accuracy was so important in MY life. Given that this board is devoted to discussing WATCHES, I thought I would try to learn something about how Rolex makes WATCHES run to such tight tolerances.

Whoa there soldier!!!! My comment wasn't directed at any one person, don't get your panties twisted!!! Threads often go off into many different directions, including not exactly the OP'S question. Snarky??? That's a great word, I may have to use it sometime!!! No offense intended!!

[The Libertine]

Originally Posted by Widows Son

All my watches are far more accurate than they need to be. Rarely do I have to coordinate a lunar landing or plan a bombing raid. If +/- a few seconds a day is really that important in your life, I'd suggest a quartz watch or a smart phone.

Totally agree.

Considering how many seconds there are in a day, will a handful of seconds (fast/slow) make that much of a difference?

[Widows Son]

Originally Posted by The Libertine

Totally agree.

Considering how many seconds there are in a day, will a handful of seconds (fast/slow) make that much of a difference?

Don't agree with me, you may get scolded!!!!

[watchwatcher]

Yeah...I think you're generally on the right track. Wearing habits do definitely make a difference.

If you did want your watch regulated, odds are the tech would take it and tell you what it was reading on his machine and then you could go from there +/-.

[HogwldFLTR]

If one is playing darts, precision would be defined by the tightness of the grouping on the target, accuracy how close the grouping comes to the targeted spot.

In a watch if the watch is consistently running seven seconds slow it has great precision as opposed to one that is off seven seconds slow one day and seven seconds fast another. In that case its average timing would be at the right time so it would be accurate but lacking precision.

Ultimately if takes a fair number of testing to determine both.

[douglasf13]

Originally Posted by The Libertine

Totally agree.

Considering how many seconds there are in a day, will a handful of seconds (fast/slow) make that much of a difference?

It depends how long you let it run.

[Xerxes77]

For me accuracy are very important and I found this accuracy on some brands Rolex, PP, Breguet, Ulysse Nardin. Unfortunately not on AP.