When I received my TO Chrono, 2 years ago, it ran continuously at +5.5/day. I did have this 2 week run where it was running at +2/day or so which is still unexplained. The watch returned to +5.5/day. For the last 4 months or so I saw my TO starting to gain time; 6.5/day and finally as high as +7.5/day. So I start to look around and see if I was doing anything different. First I needed some data, so I ran two experiment of time off of UTC against power reserve. I fully wound the watch, set it crown up on a stand, didn't move the watch and took the time gain or loss against UTC every 4 hours until the watch died.
After running the tests I read an article on magnetic effects on mechanical watches. Magnetized watches tend to run fast. So I took my compass and checked the magnetism of my watch and the surroundings. My watch did display a very little magnetism! This small magnetism may have caused the small increase in the time gain from 5.5 to 7.5 or so per day. So, I bought a demagnetizer, and ran the watch through it and redid the 70 hrs test.
Below are the graphical results of my experiment. Note the first two graphs are nearly identical with +7 on first day, flat line then decrease. Watched stopped at 63 hours. After demagnetization the gain went to +2/day, flat lined and then decreased. Watched stopped at 67 hours.
So i wound the watch 15 turns out of 40, wore it for two days, and it gained 2 secs/day. Things that I've learned:
1. Don't store your watch in top of an iPad!
2. Watch near stereo speakers is not so good!
3. A watch doesn't have to gain 1 min per day to be magnetized. Magnetism can affect the small amounts.

Sent from my iPhone using Tapatalk