It depends what grade sw220 you have.
Standard
Elabore
Top
Chronometer
They all have different accuracy ratings.
Sent from my SM-S908B using Tapatalk
Selita 220-1. Please can those of you who are movements savvy tell me what timekeeping accuracy i should expect over 24hrs with this movement.I have read +- 12 seconds from some sources but another source said +-30 seconds in 24hrs. I am interested to know which is correct.
It depends what grade sw220 you have.
Standard
Elabore
Top
Chronometer
They all have different accuracy ratings.
Sent from my SM-S908B using Tapatalk
I believe the SW220 is the SW200 with an additional day function, so the precision should be the same as the base movement. According to Calibre Corner:
4 GRADES OF SW200:
Just like the ETA caliber 2824-2, there are four grades of the SW200 movement:
Standard – adjusted in two positions; accuracy of +/-12 sec/day up to +/- 30 sec/day
Special (Elabore) – adjusted in three positions; accuracy of +/-7 sec/day up to +/- 20 sec/day
Premium (Top) – adjusted in five positions; accuracy of +/-4 sec/day up to +/- 15 sec/day
Chronometer – COSC criteria
I've had loads of SW200's and mine have fairly typically ran between -10 and +15 secs per day (mostly elabore grade). The best was an Oris Sixty Five which ran consistently at +2 secs per day. Some manufacturers regulate the movement and others certainly don't. Squale must be in the latter as I've found their SW200's all over the place in terms of daily loss or gain but i still love their watches.
Last edited by SteveDSSD; 5th June 2023 at 19:43.
accuracy of +/-12 sec/day up to +/- 30 sec/day
I find the above confusing. Surely it should just say +/-30sec/day. Unless they mean it won't be better than +/-12sec/day?
You may be able to influence* this figure by:
1 The position you put the watch at night - dial up, dial down, crown up et cetera.
2 Winding it - even though it's automatic - when you take it off at night and/or put it on in the morning.
*Remember, however:
a Try only one change at a time.
b Keep a record, taken at the same time each day.
c One or other changes may make it worse.
The best alternative, of course, is to take it to your local watchmaker and ask them to regulate it. Mine does it for £40 (for non-chronographs).
Just looked over Watch Tracker for my CWC RN300 (SW200-1 Top Grade I believe). Has averaged about +1.5spd. I also have a Smiths Navigator with manual SW220 Top, has averaged around +1spd.
Very happy with my Sellita performances.
AFAIK... it means
Up to +/-12 sec/day = what we aim to get
Up to +/- 30 sec/day = close enough that'll do
Better than +/-12 sec/day = well ain't you the lucky one
Worse than +/- 30 sec/day = yeah that ain't right
=============
FWIW I've had three watches with the SW200-1 in the past year (I know the OP is SW220)
#1 = about +5-7spd
#2 = about +1-2spd
#3 = about +7-10spd
I find that
a) what position I leave it in at night makes a difference
b) what I spend the day doing makes a difference... for example #2 if I'm busy on my feel all day every day it'll be about +4 spWEEK, if I'm lazing around the house it's more like +2 spd
=============
To the OP
Accuracy is best measured over a week, then divided by 7 to get an average...
A caseback tool and timing machine is a relatively small outlay for years of usage... and the ETA/SW range of movements are very easy to make small regulation adjustments to