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Operation Manual HORIBA APDA-371
Particulate Monitor
Date:
April, 2010
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HORIBA Europe GmbH, Julius-Kronenberg-Str. 9, D-42799 Leichlingen,
: +49(0)2175-8978-0,
: +49(0)2175-8978-50
Page 30
Nozzle Cleaning
The figure below shows the difference between good and bad filter tape spots. The tape on the left is from a properly
operated APDA-371 with a clean nozzle and vane. Notice the particulate spots have very crisp edges, are perfectly
round, and are evenly distributed.
The tape on the right is from a unit which has not been properly maintained. A spot of debris has built up on the vane,
and is punching a pin-hole at the edge of each spot. These holes can allow beta particles to get through un-attenuated
which negatively affects accuracy even if the nozzle is not leaking. The spots also show a “halo” effect due to air leaking
in around the edged because the debris has built up to the extent that the nozzle no longer seals correctly. These faults
are easily corrected and prevented by keeping the nozzle and vane clean.
APDA-371 hourly filter tape spots
Vane
Nozzle Lip
Cotton
Applicator