TM 5-6675-323-14
( 7 ) D e t e r m i n e l e n g t h c o n s t a n t , CL ( m u l t i p l i e r ) , u s i n g t h e f o l l o w i n g f o r m u l a :
= Length of constant
CL
D
= Length of known object
R
= Counts generated by measuring length of known
object
Example:
O n aerial photograph of unknown scale or magnification where a telephone
l i n e is visible, use the known distance between two telephone poles, 105
feet, for D in formula.
( 1 ) With linear measuring probe, measure the known distance (between
two telephone poles) to obtain R.
(2) The value shown on the auto-scaler LED display (5692) can be used
for R in the formula
(4) Result is 0.02.
Press
and
to
display
six
decimal
places,
0.018447 =
C L
(5)
press
to
activate
PRINT
command.
( 8 ) K e y i n CL v a l u e
(computed
with
known
length
of
object
in
photograph
being
measured).
Press
and
.
Do not release until ready to begin measurement.
(9) Press foot switch.
(10) Position linear measuring probe so that pricking pin is at beginning of
length to be measured. Release foot switch.
(11) Make measurement by tracing length of line with linear measuring probe.
(12) Press
to activate PRINT command and freeze count.
Area measurements on aerial photographs of unknown scale or magnification.
T o make area measurements of aerial photographs, there must be a known length of an
object.
T h i s known factor must be used to compute constants needed for
measurements.
( 1 ) Assemble QPS with planimeter.
(2) Activate QPS:
(a) Plug foot switch into ACCU input jack on back panel of auto-scaler.
( b ) P l u g p l a n i m e t e r i n t o E2 e n c o d e r s o c k e t o n b a c k p a n e l o f a u t o - s c a l e r .
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