user manual Owner's manual

MNU Series Ultrasonic Sensors Rev. B1, 5/13
8
Automa! on Products Group, Inc.
APG...Providing tailored solu• ons for measurement applica• ons
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Stand Pipe Moun! ng
Stand pipes are used to provide headroom at
the top of a tank when the target is expected
to come closer to the sensor than the
minimum blanking distance. It’s very cri! cal
that the stand pipe be installed perpendicular
to the target. This is especially important
on longer range applica! ons. The pipe must
have smooth walls (no joints) and no burs or
obstruc! ons. If possible, cut the end of the
pipe at a 10°-45° angle (see drawing). Use
the largest diameter pipe and shortest length
possible. As a general rule, the diameter of
the pipe should be 1/2 the length. The pipe
ID must remain the same through it’s en! re
length.
S! lling Pipe Moun! ng
S! lling pipes provide access to diffi cult areas
and help eliminate problems with foam.
The pipe must have smooth walls (no burs
or joints). Because the sound waves will
concentrate and propagate down the inside
walls of the tube, any irregulari! es on the
tube walls may produce echo returns and
cause false readings. S! lling pipes are limited
to liquid targets that will not leave heavy
deposits on the tube walls. Because the
sound waves are confi ned inside the pipe,
it is usually necessary to greatly reduce the
sensors sensi! vity and pulses se$ ngs. A vent
hole must be provided at the top of the pipe.
Be sure to keep the vent hole inside of the
blanking area.
Cut at angle
when possible
Vent Hole