TM 5-6675-323-14
(1)
Position
micrometer
at
midscale.
(2) Position left optical dot over point A.
(3) Lift adjustment pin and position right optical glass mount at adjustment
hole closest to point A1.
(4) Position left optical dot over point A. Unlock locking lever on micro-
meter. Then turn knurled knob on micrometer to left or right until right optical
dot is over point A1.
M a k e datum plane reading.
c.
(1) Choose known elevation point that is on both photographs (or point that
will be at reference elevation).
(2) Place left optical dot over this point on left photograph.
(3) Place right optical dot over same point on right photograph.
(4) Look through stereoscope and turn micrometer knurled knob u n t i l t w o
o p t i c a l d o t s a r e s e e n a s o n e d o t t h a t l o o k s a s i f i t c o n t a c t s g r o u n d o n reference
point.
d. Read micrometer scale.
10-9
