Model 239-1F Floor Monitor
December
2010
5. MAINTENANCE
Periodic
maintenance
consists of checking
the general condition of the detector, gas
tubing/fittings, signal/HV cable, and the
window. Malfunction of the detector could
be caused by a gas leak or a broken HV wire
inside the detector.
In case of low count, the detector should
be checked for gas leaks. Check the input and
output flowmeter on the cart. A reduced or
no output flow compared to the input would
indicate a gas leak in the system. Any holes
in the window will allow counting gas to
escape causing degradation of detector
efficiency. If the window needs replacing in
the detector, the detector should be checked
both for gas leaks and HV shorts before
replacing detector on the cart.
Indication of a broken wire is low or
erratic HV reading. Foreign particles, wire
tails on the standoff posts, or solder peaks can
cause excessive counts. Loose wires can
cause reduced count.
To replace a broken or loose wire, remove
the window, being careful not to tear or
puncture the window material. Replace the
wire and clean the chamber thoroughly.
Inspect the gasket for proper condition before
replacing the window. Check for gas leaks
and proper operation before installing the
detector on the cart.
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