Troxler 3411-B, Manual Of Operation And Instruction

Page: 88 / 109

Appendix B-12
W
W
o
o
r
r
k
k
i
i
n
n
g
g
w
w
i
i
t
t
h
h
R
R
a
a
d
d
i
i
a
a
t
t
i
i
o
o
n
n
S
S
o
o
u
u
r
r
c
c
e
e
s
s
The 3400-B series contains two radioactive sources. The Am-
241:Be source is located in the center of the gauge base.
Never
attempt to remove this source!
The Cs-137source is welded inside the tip of the source rod.
When located in the SAFE (shielded) position, the source is
surrounded on all sides by tungsten and radiation is reduced to
safe levels. The source rod does not need to be removed to
troubleshoot the scaler and preamplifier board.
NOTE
When performing maintenance on the gauge, always
monitor radiation by wearing a dosimeter.
To perform routine maintenance, you may need to remove the
bottom shield to clean the cavity beneath the source. To
minimize exposure while cleaning, proceed as follows.
1.
With the source in the SAFE position, place the gauge on its
side.
2.
Remove the bottom plate.
3.
Remove the sliding tungsten shield. When removing the
shield, stand to the side of the gauge to minimize exposure.
4.
Move away from the gauge and keep others away when
shielding is not present.
5.
Dry the block well. Lightly grease the top sloped surface of
the block and quickly replace the spring, block, and
baseplate.
This procedure will keep exposure to minimum levels. Exposure
to the hands will be higher than to the body, but is well within
safe levels established by radiation authorities. The cleaning
operation should be conducted quickly and will not take more
than five minutes.