Accuracy - the evidence.

[Rock]

Being retired I have plenty of time on my hands so I do a daily 'Time check/record' on the Sub and DJ. I now have several years data.
The data is very consistent year to year.

I can state that the Subs accuracy is best in Winter (May - October) when accuracy is +1 - 1.5 secs/day and worst in Summer (November - April) when accuracy is +2 - 2.5 secs/day.

The DJ is the opposite being worst in Winter being +2 - 3.5 secs/day and best in Summer at +1 - 2 secs/day.

How about that. Anyone else done an empirical study?

[Abdullah71601]

My Milgauss has been consistently +0.5 for the past year.

[stevep1041]

My month old Datejust ii is running at less than +.5 seconds PER WEEK at the moment, compared to my atomic radio/alarm clock.

[Thatguy]

Interesting. Are they on a winder when not worn and do they get the same wrist time? Don't know if activity level would affect accuracy......


Sent from my iPhone using Tapatalk

[padi56]

Last time I checked was July 1983 just checked my watch now and its gained 1.9999987 of a second since then.But on a serious note all this checking stuff I gave up decades ago, I now check my watches around once a month or so. Then they are seldom more than a minute or two out that's accurate enough for me.Now the escapement of a mechanical watch in 24 hours pushes the gears 432,000 times and a day has 86,400 seconds.So for any mechanical watch to run within a few seconds a day is a mechanical marvel, given the fact that the movement is constantly affected by the earth's gravity, metal expansion and contraction, temperature variations, subtle changes in lubrication and friction, shocks, and so on.The fact is that no mechanical watch made will keep perfect time, very close yes but perfect no. But please guys to not to anal about a few seconds either way trust me far more important things in daily life.

[Rock]

Hi Wayne, yes they are alternated day by day so the one not being worn is on the winder.
They both spend almost exactly the same amount of time on the wrist and winder.
I had a hunch that the ambient temperature was having an impact on accuracy but it was only when I had a look at the data from several years that I could see clearly that there was a very consistent pattern.

Ha! pretty accurate Peter! Of course you are right about not being too anal but I am a lost cause and unless I go back to work I will probably continue to check daily - it amuses me (small things and small minds)

[Anthon]

Please post exactly how you measured the performance of you watch, otherwise the numbers mean nothing. I highly doubt that your watch only gains a second and a half over a 24 hour period sitting crown up for example..

[Canook]

Originally Posted by padi56

Last time I checked was July 1983 just checked my watch now and its gained 1.9999987 of a second since then.But on a serious note all this checking stuff I gave up decades ago, I now check my watches around once a month or so. Then they are seldom more than a minute or two out that's accurate enough for me.Now the escapement of a mechanical watch in 24 hours pushes the gears 432,000 times and a day has 86,400 seconds.So for any mechanical watch to run within a few seconds a day is a mechanical marvel, given the fact that the movement is constantly affected by the earth's gravity, metal expansion and contraction, temperature variations, subtle changes in lubrication and friction, shocks, and so on.The fact is that no mechanical watch made will keep perfect time, very close yes but perfect no. But please guys to not to anal about a few seconds either way trust me far more important things in daily life.

this!

[Anthon]

Originally Posted by padi56

Last time I checked was July 1983 just checked my watch now and its gained 1.9999987 of a second since then.But on a serious note all this checking stuff I gave up decades ago, I now check my watches around once a month or so. Then they are seldom more than a minute or two out that's accurate enough for me.Now the escapement of a mechanical watch in 24 hours pushes the gears 432,000 times and a day has 86,400 seconds.So for any mechanical watch to run within a few seconds a day is a mechanical marvel, given the fact that the movement is constantly affected by the earth's gravity, metal expansion and contraction, temperature variations, subtle changes in lubrication and friction, shocks, and so on.The fact is that no mechanical watch made will keep perfect time, very close yes but perfect no. But please guys to not to anal about a few seconds either way trust me far more important things in daily life.

Some people need the accuracy in their daily private or professional life.

I once owned a Meistersinger one-hand-only watch, with only 5 minute marks. It was advertised as a watch that slows you down, takes away stress etc. etc. It drove me nuts! Great for holidays or weekends, but when you need to know if there is enough time to buy a sandwich before your train leaves...utterly useless.

[Andad]

The precision of your watches is is consistent and within the limits Rocky.
The accuracy is not so good.

For a watch to be accurate it would need to be plus or minus a few seconds at any time during the year.

Your precision is in seconds/day and travelling from the Old Dart to Oz in the old days you would have missed it by miles.

I have checked all my watches on my timegrapher, I just hope Padi never finds out.

Pete.

[Rolex fan 61]

Really??????????

[Eva123]

Originally Posted by stevep1041

My month old Datejust ii is running at less than +.5 seconds PER WEEK at the moment, compared to my atomic radio/alarm clock.

My month old DJII runs +2.5s and I thought that it is quite your watch accuracy is incredible.

[padi56]

Originally Posted by Anthon

Some people need the accuracy in their daily private or professional life.

I once owned a Meistersinger one-hand-only watch, with only 5 minute marks. It was advertised as a watch that slows you down, takes away stress etc. etc. It drove me nuts! Great for holidays or weekends, but when you need to know if there is enough time to buy a sandwich before your train leaves...utterly useless.

Well I am 100% sure that know ones life or even there work today is run to the absolute second, if it does then I feel truly sorry for them.Been wearing Rolex watches for almost 40 years yet I have never missed a bus, train,boat, plane, or late for any appointment, if my watch might be a few seconds or so fast or slow.

[The Libertine]

Originally Posted by padi56

But on a serious note all this checking stuff I gave up decades ago, I now check my watches around once a month or so. Then they are seldom more than a minute or two out that's accurate enough for me. The fact is that no mechanical watch made will keep perfect time, very close yes but perfect no. But please guys to not to anal about a few seconds either way trust me far more important things in daily life.

My thoughts exactly. Never been accused of being "x" number of seconds early, or late, so as long as my watch keeps me on time, I am happy.

[Anthon]

Originally Posted by padi56

Well I am 100% sure that know ones life or even there work today is run to the absolute second, if it does then I feel truly sorry for them.Been wearing Rolex watches for almost 40 years yet I have never missed a bus, train,boat, plane, or late for any appointment, if my watch might be a few seconds or so fast or slow.

Trains in Holland run exactly on time, on the second (well, most of the time) . Knowing the exact time will mean the difference between being able to buy that sandwich in time or not. And this is just one simple example. There are plenty of other examples, both personal and in professional life where one needs to account for every minute. An accurate watch is essential in those cases. No need to feel sorry for me Padi.

I understand where you are coming from, this obsession regarding accuracy can be a bit tedious, especially since no one bothers to explain how they measure their accuracy in the first place.

A watch is only as good as the time it tells. I would not buy a Rolex if it would not be consistently accurate.

[77T]

Well I never thought much about temperature unless it was extreme over long period of time.
Does your home temperature vary so much that it would matter? Or are you outside for more than a few hours a day?

Could there be additional factors like axial tilt at play here?

Inquiring minds...


Sent from my iPhone using Tapatalk

[RobJordan]

It's interesting to find a thread here about timekeeping and not just about the aesthetic of the watches. Thank you for sharing your findings, Rocky!

[Abdullah71601]

Originally Posted by Anthon

Trains in Holland run exactly on time, on the second (well, most of the time) . Knowing the exact time will mean the difference between being able to buy that sandwich in time or not. And this is just one simple example. There are plenty of other examples, both personal and in professional life where one needs to account for every minute. An accurate watch is essential in those cases. No need to feel sorry for me Padi.

I understand where you are coming from, this obsession regarding accuracy can be a bit tedious, especially since no one bothers to explain how they measure their accuracy in the first place.

A watch is only as good as the time it tells. I would not buy a Rolex if it would not be consistently accurate.

Accuracy is irrelevant to your argument. Your argument requires a watch that is synchronized to the train conductors watch. You can have the most accurate watch in the world, but if it doesn't match the train system you will still be left standing on the platform.

You first need to define the time reference before you can measure whether your timepiece is accurate in context of your argument. The variation between your reference and your watch will define how accurate your watch is. Any other measurement is useless for your needs.

[watchwatcher]

I've not really noticed a difference in seasonal findings...that's interesting.

[The Libertine]

Originally Posted by Abdullah71601

Accuracy is irrelevant to your argument. Your argument requires a watch that is synchronized to the train conductors watch. You can have the most accurate watch in the world, but if it doesn't match the train system you will still be left standing on the platform.

You first need to define the time reference before you can measure whether your timepiece is accurate in context of your argument. The variation between your reference and your watch will define how accurate your watch is. Any other measurement is useless for your needs.

I agree. Might miss a train by a few, or even a minute, but never by one second.

[Sandblaster]

I set my watch 10 minutes fast so I'm never late. Exactly 10 minutes fast.

Anyone else do that?

I have meetings and con calls. I'm never late for anything.

[Anthon]

Originally Posted by Abdullah71601

Accuracy is irrelevant to your argument. Your argument requires a watch that is synchronized to the train conductors watch. You can have the most accurate watch in the world, but if it doesn't match the train system you will still be left standing on the platform.

You first need to define the time reference before you can measure whether your timepiece is accurate in context of your argument. The variation between your reference and your watch will define how accurate your watch is. Any other measurement is useless for your needs.

I don't agree. I'll use the train example, but obviously it applies to every time sensitive situation.

First of all, the trains run on atomic time. They depart on the minute exactly. In order to know how much time I have left before my train departs I will need a watch that can synchronized to atomic time. So far no problem.

The reason I need an accurate watch is that I don't have the time to synchronize my watch on a daily basis. This means that:

1. the daily gain or loss should be small
2. the daily gain or loss should be manageable


An accurate watch excels in both points. Ask the guys at COSC.

[Anthon]

Originally Posted by Sandblaster

I set my watch 10 minutes fast so I'm never late. Exactly 10 minutes fast.

Anyone else do that?

I have meetings and con calls. I'm never late for anything.

That means standing on a cold train platform for ten minutes waiting..

[theloxmyth]

Originally Posted by Sandblaster

I set my watch 10 minutes fast so I'm never late. Exactly 10 minutes fast.

Anyone else do that?

I have meetings and con calls. I'm never late for anything.

No, but I always arrive early for appointments, just the same.

Our local radio station, the first in the nation (KDKA), "tones/chimes" on the hour, and I look to see how close to (semi) perfect I'm set to.

[Abdullah71601]

Originally Posted by Anthon

I don't agree. I'll use the train example, but obviously it applies to every time sensitive situation.

First of all, the trains run on atomic time. They depart on the minute exactly. In order to know how much time I have left before my train departs I will need a watch that can synchronized to atomic time. So far no problem.

The reason I need an accurate watch is that I don't have the time to synchronize my watch on a daily basis. This means that:

1. the daily gain or loss should be small
2. the daily gain or loss should be manageable


An accurate watch excels in both points. Ask the guys at COSC.

The trains run on an approximation of atomic time. The same as cell phones, GPS, and other devices. There is variation between the reference atomic clock and the train, just like there is variation between your smart phone and the atomic clock. It might only be a second or two, but those seconds may not be the same as the error on your watch.

The point is that unless you are operating an antiballisitic missile system or calibrating the GPS satellite network, you really don't need to be as accurate as an atomic clock. And no mechanical watch made will ever attain that level precision and accuracy, there are just too many uncontrollable variables.

Not to mention, time dilution....

[Coldnore556]

As I am still very new to the mechanical watches, how do you guys check the time so precise as to know if the watch has gained or lost a second or less? Just got my first Rolex a week ago and would love to check this.

[Anthon]

Originally Posted by Abdullah71601

The trains run on an approximation of atomic time. The same as cell phones, GPS, and other devices. There is variation between the reference atomic clock and the train, just like there is variation between your smart phone and the atomic clock. It might only be a second or two, but those seconds may not be the same as the error on your watch.

The point is that unless you are operating an antiballisitic missile system or calibrating the GPS satellite network, you really don't need to be as accurate as an atomic clock. And no mechanical watch made will ever attain that level precision and accuracy, there are just too many uncontrollable variables.

Not to mention, time dilution....

Of course no mechanical watch will be that accurate, but the accuracy must be manageable. I'm sure you would agree that a watch that varies by ten 16 seconds per day is next to useless compared to a well maintained Rolex that can be managed to within 2 seconds of atomic, if your train runs on schedule and on atomic time.

If you don't care for precise time, for example if you just use your watch to see if it is diner time already, then accuracy is not required and any Chinese ETA copy will do.

[Anthon]

Originally Posted by Coldnore556

As I am still very new to the mechanical watches, how do you guys check the time so precise as to know if the watch has gained or lost a second or less? Just got my first Rolex a week ago and would love to check this.

You will not get an answer to this question. I tried for more than a year :thumbs:

First step is to get hold of atomic time. time.is is a good reference for this.
Then we need to agree on how to interpret the figures.
Here is where it gets murky.
On the wrist, on a winder, next to your bed, playing soccer...what are we talking about?
Crown up, crown down, face up, face down...what?

[The Libertine]

Originally Posted by Anthon

Here is where it gets murky.
On the wrist, on a winder, next to your bed, playing soccer...what are we talking about?
Crown up, crown down, face up, face down...what?

Many people must miss their trains then...

[Sandblaster]

Originally Posted by Anthon

That means standing on a cold train platform for ten minutes waiting..

Wear a jacket lol. You have to dress season appropriate, no?

Plus being fast means you're not late. You don't have to stand out on the platform.