S
S
o
o
u
u
r
r
c
c
e
e
R
R
o
o
d
d
P
P
o
o
s
s
i
i
t
t
i
i
o
o
n
n
s
s
As shown below, the source rod can be placed in the SAFE
position, background (BGD) position, or the direct transmission
position. When not taking measurements, keep the source rod in
the SAFE position at all times.
Safe Position
Background
Direct
Transmission
Figure 4. Source Rod Positions
In the background and direct transmission positions, the source
rod extends into a pre-drilled hole described in the next chapter.