5.2 Installing bubble chamber for ground water
To install the bubble chamber for ground water, proceed as follows:
䡵
Determine depth of the bubble chamber (e.g. using a contact gauge). The
bubble chamber must be positioned under the lowest expected water level.
Depth = distance from bubble opening to upper edge of the
top cap
䡵
Push the measuring tube into the cable gland of the bubble chamber as far as
it goes.
䡵
Tighten the cable gland firmly by hand
䡵
Cut suspension cable to length;
suspension cable length = depth +
125 cm
(to protect the suspension cable from being twisted off, it can be
melted, with a cigarette lighter for example).
䡵
Feed the suspension cable through the hole in the bubble chamber as shown in
Figure 6 and tie firmly.
䡵
Slide cover into position B (upwards), see Fig. 6.
M
easuri
n
g pipe
Suspe
n
sio
n
cable
bubble cha
m
ber
M
etal pi
n
Cover i
n
positio
n
A
Bubble ope
n
i
n
g
Cover i
n
positio
n
B
Cable
gla
n
d
Hole
Bubble pot
Fig. 6: Installing bubble
chamber for ground water.
When lowering the bubble chamber, the
cover must be in position B! The cover
prevents water entering the measuring
tube during installation.
During initial startup, over pressure builds
up in the measuring tube. As a result, the
cover falls back to position A and opens the
measuring tube in the process.
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