T M 5 - 6 6 7 5 - 2 5 0 - 20
2-16. DETERMINATION OF AZIMUTH VALUE FOR REFERENCE MIRROR (Continued)
L O C A T I O N / l T E M
A C T I ON
R E M A R KS
S E R V I C E ( C o n t i n u e d)
k.
R e c o r d
l .
O b t a in
the vernier scale reading (1).
the direct horizontal reading by adding
the recorded readings of the horizontal and
vernier scales.
m .
Obtain reverse readings by doing the follow-
ing:
(1)
(2)
Release the vertical lock
( 1 ) a n d r a p i d l y r o t a t e
t e l e s c o p e 1 8 0 d e g r e e s
a b o u t t h e h o r i z o n t a l
axis; tighten the vertical
lock.
R e l e a s e t h e h o r i z o n t a l
l o c k ( 2 ) a n d r o t a t e t he
t h e o d o l i t e a l i d a d e 1 80
d e g r e e s ( c l o c k w i s e ) ;
t i g h t e n t h e h o r i z o n t al
lock .
2-72
