TM 5-6675-322-14
h = Difference in elevation between datum plane and first point
i n f e e t.
= D i f f e r e n t i a l p a r a l l a x u s e d f o r f i r s t d e t e r m i n a t i o n.
= Difference in elevation between datum and second point.
= Differential parallax for second point measured in mili-
meters.
Example (1):
(1) Check distance between datum and point to be measured. (Must be between
8 - 1 / 2 i n . a n d 4 - 1 / 2 i n .)
(2) Make datum plane reading (4-6.2c). Micrometer reads 3.38mm.
4-12