NUS-7
NUS-7 K03/0617
Seite 5
6.2 Installation (Liquid Level Measurement)
Never mount two ultrasonic level-measuring devices in one container,
because the two devices can interfere with each other's functioning.
POSITION
The optimal position of the NUS-4 is on
the radius
r = (0.3 … 0.5) R of the (cylindrical) tank
/ silo.
(Take also sonic cone on page 39 into
consideration.)
SENSOR
ALIGNMENT
The sensor face has
to be parallel to the
surface of the liquid
within
2-3
.
TEMPERATURE
Make sure that the
transmitter will be
protected against
overheating by direct
sunshine.
Sunshade
OBSTACLES
Make sure that no in-
flow path or objects
(e.g. cooling pipes,
ladders, bracing
members,
thermometers, etc.) or
no tank wall of the
ragged surface
protrude into the
sensing cone of the
ultrasonic beam.
One fix object in the
tank / silo that disturb
the measurement can
be blocked out by the
optional programming
unit.
FOAM
Foaming of the liquid surface may render ultrasonic level
metering impossible. If possible, a location should be found,
where foaming is the least (device should be located as far
as possible from liquid inflow) or a stilling pipe or well should
be used.
WIND
Intensive air (gas) movements in the vicinity of the ultrasonic
cone is to be avoided. A strong draft of wind may "blow
away" the ultrasound.
Devices with lower measuring frequency (40, 20 kHz) are
recommended.
FUMES / VAPOURS
For closed tanks containing chemicals or other liquids, which
creats fume/gases above the liquid surface especially for
outdoor tanks exposed to the sun, a strong reduction of the
nominal measuring range of the ultrasonic device is to be
considered during device selection.
Devices with lower measuring frequency (40, 20 kHz) are
recommended in these cases units.
