Nivobob
®
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NB 3000
gi130109
36
Continuous level measuring system
NB 3000
Technical information / Instruction manual
page G
Commissioning: Interface measurement
Deflection-
pulley-bar
Sensor weight
Stainless steel or
plastic discs
Lid
Adjustment nut
Applications
Measurement of solids in water like mud, sand, bed ash, sediment, stones etc.
Rope version:
The material surface can be soft / muddy or compact. Sensitivity adjustment possible.
Tape version:
The material surface must be compact (the sensor weight cannot sink in). No sensitivity
adjustment possible.
Principle
The sensor weight penetrates into the water and stops when touching the solid surface.
General items
Sensitivity adjustment (rope version)
General
The sensitivity (needed release force for the sensor weight when touching the solid surface) can be set to the
requirements of the application.
Sensitivity adjustment is done by lowering the sensor weight into the water by using the "Manual motor
control" (see page G29).
1. Coarse adjustment
Coarse adjustment is done to avoid the detection of the water surface.
When penetrating into the water, the weight must not float. This can be checked by watching the deflection-
pulley-bar. If the deflection-pulley-bar will move briefly upwards while penetrating into the water, the sensor
weight floats and needs to be heavier. This is achieved by unscrewing the lid of the sensor weight and
replacing one or more plastic discs by stainless steel discs. For soft/muddy surfaces the sensor weight shall
be as light as possible to keep it from sinking into the bulk material surface (see step 2).
Note: It is important that the sensor weight is completely filled with discs to avoid intrusion of air.
2. Fine adjustment
Fine adjustment is done to keep the sensor weight from sinking into a soft/muddy material surface.
• Turn adjustment nut anti clockwise:
measurement becomes more sensitive (for soft/muddy surface)
• Turn adjustment nut clockwise:
measurement becomes less sensitive (for more compact surface)
• Fix the adjustment nut with the counter nut
The adjustment was sucessful if the sensor weight penetrates the water surface easily and detects the
material surface without sinking in.
cw
