Quote:
Originally Posted by Gab27
Generally speaking, as a snapshot to assess movement health, at what single point in time is measuring amplitude going to be most important? Fully wound? 24 hours out? Or is trend data so important that a single point-in-time measurement (or a series of measurements at the same point-in-time) could potentially miss 'the big picture'?
|
I always start with full movement winding. You already have a very first idea about the health of your caliber. There are several graphs in this thread, which illustrate the spread of results for different watches with the same 3235 or 3285 movements after full winding.
A characteristic footprint for a good movement is a rather slow decrease of amplitudes over time, nice examples for a 3130 (Andad) and 3187 (saxo3) are in post #414.
Such "amplitude vs. time" measurements are often done in one position only, dial up (DU), which is the most 'comfortable' caliber position (also dial down, DD) with lowest friction.
A coarse picture you obtain measuring only at t=0 and t=24 h. After 24 h the amplitudes must be above 200 degrees, which is the Rolex specification. I would even say above 230 degrees.
Quote:
Originally Posted by Gab27
Additionally, is there value in measuring amplitude without manually winding at all and simply measuring at the point to which continuous wrist wear will wind the watch to?
|
Yes, for sure. The most natural way is wearing your watch and wind it with your wrist. You first fully wind it and set the time, then do a reference measurement and simply wear it afterwards. From time to time you measure 5-position-averaged rates and amplitudes. I have done that often in the past, also for watches with other 31xx and 15xx calibers.
Quote:
Originally Posted by Gab27
For example, my 3130 Sub consistently loses about 1.9 seconds a day with continuous wrist wear, whereas when fully wound the watch loses less time.
|
The 3130 is a very good movement and the -1.9 sec/day would not worry me too much. Important is that the time loss is consistent, i.e. you always loose more or less -2 sec/day. This can be regulated by a watchmaker. I prefer that my watches run in the positive range.
Quote:
Originally Posted by Gab27
So whatever level my wrist wear winds the watch to, I assume it is a good bit less than a fully wound mainspring (and that amplitude would be lower?)
|
Yes, probably.
Quote:
Originally Posted by Gab27
Is that reading of amplitude at a 'real world' level of use of benefit?
|
Yes, certainly. It also includes the time where your watch remains at rest, e.g. overnight, that reflects the reality for most.
Quote:
Originally Posted by Gab27
I just ordered a timegrapher yesterday so I've been reading up about using it, but I think one area I am lacking in is a clear picture of how to interpret the data.
|
Understandable.
Quote:
Originally Posted by Gab27
If this is straying too far off topic, I sincerely apologize but your post is great and I am in the process of trying to learn more.
|
No, you are very welcome.
To answer all your valid questions with real data, you can have a look at the graph below, which displays several things for you.
This SD43 keeps a high amplitude (in DU position) over a long time, after 60 hours it’s still above 200 degrees. During the same test, I also measured the accuracy (or timekeeping) with a timegrapher-independent app (WatchTracker). The blue curve (no fit, only a guide to the eye) shows that the 3235 caliber is running consistently with about +5 sec/day, which gets smaller towards the end of the power reserve. This +5 sec/day accuracy one can regulate to become less. At present I don't care and prefer to observe how it changes over time.
