ARINC instrument sizes
Question from an ancient.....
How is, as an example, the ARINC 5-inch instrument standard (5 ATI) defined?
I can't afford a new copy of ARINC 408A, and after googling left, right and centre, I'm confused.
Does the 5" refer to the cutout?
Does it refer to the available 'square' on the instrument panel? It would seem not, since bezel dimensions I've seen appear to go beyond that.
Does it refer to the instrument casing (which is really the same as the cutout), but in that case what is the size of the 'square' on the panel?
Mostly asking for somebody else, but I've now been so often baffled myself, that I thought I'd venture out here and ask.
(I know, there's 3", 3.5" etc. etc., that's not my question).
CJ