Is it just resistance of amplitude changes due to mainspring length, but also positional changes?

 

Isochronism is the resistance to a change in rate of an oscillator, due to a change in displacement (amplitude).

In watchmaking terms, this is a term used to relate to change over time as the mainspring winds down (lower toque = lower amplitude), rather than amplitude changes related to changes in position. Variances related to changes in position are referred to as positional variation, or Delta.

These are kept separate generally, but the Delta can certainly change between one set of checks and another, due to lack of isochronism.

For example the Delta at full wind may be allowed to be say 12 seconds measured over 5 positions, but can be as much as 15 seconds over 5 positions for the same watch, 24 hours after full wind.

 

Thanks for clarifying.

 

www.isochrono-holic.com

 

www.don’tquityourdayjob.com

 

The links are broken.

 

www.don’tfollowboguslinksintendedtobecomical.com

 

And again... WTF?

It's so easy to copy a link guys. Let me know what device you're on and I'll see if I can help.

 

www.thatDarlinboyisalwayspullingyourleg.com