Apple 5280, 5260 manual

5260 and 5280 Adjustments	Light Meter Setup - 4
	readings, verify the
	readings with a known-good
	light meter or photometer.
	Also check the age of the R77
	light meter by its four-digit
	manufacturing date stamp
	(such as 0398 for March
	1998).
	Caution: Dropping the
	meter can permanently
	damage its accuracy. A
	shock-damaged meter might
	read incorrectly or its
	pointer may not drop to
	zero.