TM 5-6675-322-14
NOTE
The following procedure is required if observed range does not equal
known or measured range.
(a) Rotate range dial until images merge.
(b) Place coin or flat tip screwdriver in range adjustment screw
s l o t .
( c ) H o l d s c r e w p o s i t i o n a n d f o r c e r a n g e d i a l t o r i g h t o r l e f t u n t il
c o r r e c t r a n g e i s i n d i c a t e d.
(d) Repeat observation to confirm range is accurately set.
h . O p t i c a l t r e e m e a s u r e r.
(1) Measurement of basal area:
(a) Observer chooses scale 1, 2 or 4 based on tree diameter. Choice of
scale must be based on experience.
Small-diameter trees are normally counted with
scale 1, larger trees are counted with scale 2, and largest trees are counted with
scale 4.
The counting scale chosen should be representative of average size of
visible trees and not be changed from sampling point to sampling point.
Scales 1
and 2 are the most commonly used in forestry to determine basal area.
Example:
Counting scale 2 is chosen if visible trees have an average diameter that –
i s c l o s e t o o r s l i g h t l y l a r g e r t h a n s c a l e 2 .
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