Technical data
BKI 03 ATEX 027X spa3804a0600p_06
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3.2 OPEN C HANNEL FLOW MEASUREMENT
The unit is suitable for open channel flow measurement with the constructive works listed in 5.3.8.
For ultimate accuracy, install the sensor as close as possible above the expected maximum water level (see minimum measuring range).
Install the unit in a place defined by the characteristics of the metering channel along the longitudinal axis of the flume or weir. In case of Parshall flumes
supplied by NIVELCO the location of the sensor is marked.
In some cases foam may develop on the surface. Make sure that the surface, opposite to the sensor, remains free of foam for proper sound reflection.
The unit should be fixed so that it‘s position would not change.
From measurement accuracy point of view the length of the channel sections preceding and following the measuring flume and their method of joining to the
measuring channel section are of critical importance.
Despite of the most careful installation, the accuracy of flow metering will be lower than that of specified for the distance measurement. The features of the
flume or weir applied will determine it.
Devices should be protected against overheating due to direct sunshine by using sunshades.
4. WIRING
Make sure the terminals in the box are not under power (Use shielded cable 6 x 0.5 mm
2
suggested in
the technical data or stronger).
After powering the necessary programming can be performed.
Wire colours:
Green – relay C1 output White – I, one of the points of current loop, power supply and HART (polarity independent)
Yellow – relay CC output Brown – I, other point of current loop, power supply and HART (polarity independent)
Grey – relay C2 output Black – GND, functional earthing and shielding point
White
Green
Yel low
Grey
Brown
Black
Junction box
Power
suppl
y
Power supply
+ HART
+ Current output
HART modem
I
white
(
brown
)
brown
(
white
)
green
black
R
C1 C2
CC
yellow
grey
mA
TRANSMITTER
Extension of the integrated cable:
Should extension be needed the use of connection box is
suggested.
The shielding of the two cables should be connected and
grounded at the signal processing device.