Milltronics OCM II PL-269, Instruction Manual

Page: 104 / 107

APPLICATIONS WITH STANDPIPE
In some OCM II applications, access to the channel must be made via a standpipe. In such cases, the
transducer may be hung from a blind flange that will mate to the flanged standpipe.
The stand pipe length should be as short and the diameter as large as possible. As a rule of thumb, the
-3 dB cone of the sound beam should not intersect the standpipe wall in applications opening into a larger
area. Otherwise, additional blanking will be required to compensate for the interference zone created by the
opening (refer to section Appendices \ Troubleshooting).
sound beam
intersects
pipewall
reflection at
interference
zone created by
opening
6 °
blanking extension
of 150mm (6") past
end of standpipe
may be required
no additional
blanking required
transducer
radiating
surface
no change
in area
opening to
larger area
FIG. 7
PL-269 10 – 8