KROHNE BM 100A Handbook - Manual (Page 30)

30 Handbook BM 100 A
How to set an analogue current output scale
User menu functions 1.3.1 to 1.3.4 (& 1.3.5 to 1.3.8 for a second analogue output)
This set of functions allows users to set up a scale. The minimum (4mA) and maximum (20mA)
values of an analogue current output should ideally lie within the device’s active measuring zone, as
the display will freeze when the signal is lost.
Refer to the measurement limits table for each probe type in the introduction. Refer also to the stqrt
of section 3.4.3 for the advantages of changing tank height.
Example procedure 4:
• personalise a measurement scale
• select “Level” as the current output parameter for the scale to be set up from the tank bottom
• choose suitable minimum and maximum values for the scale.
Step Action Press buttons to
finish step Information displayed at
the end of each step
1 Start from Operating Mode screen n/a 6750
LEVEL mm
2 Go to Fct. 1.3.1
→,→,↑,↑,→ Fct. 1.3.1
FUNCTION.I.1
3 Enter data set field (current value:
Distance) → DISTANCE
4 Set to Level. ↑,↑,↑ LEVEL
5 Exit data set level and go to fct. 1.3.2 ↵,↑ Fct. 1.3.2
RANGE I 1
6 Enter function (current value: 4 – 20
mA) – to set the error output to 3.7 mA
or 22 mA or having no error output. →
4 - 20
7 Modify value to 4 – 20 mA with error
output at 22 mA. ↑,↑
4 – 20 /22=E
5 Exit data set field and go to fct. 1.3.3.
Enter (current value: 00000.0 mm) – to
set level that corresponds to the
minimum current output 4 mA. ↵,↑,→
00000.0
mm
6 Modify value to 01000.0 mm (this sets
the minimum point 1 metre above the
tank bottom). The tank is considered
to be empty below this point. →,↑ 01000.0
mm
7 Exit data set level and go to fct. 1.3.4.
Enter function (current value: 14000.0
mm) – to set level that corresponds to
the max. current output 20 mA ↵,↑,→ 14000.0
mm
9 Change to 9600.0 (this sets the
maximum below the top dead zone).
The tank is considered to be full above
this point ↑,↑,↑,↑,↑,↑,↑,↑,↑,
→,↑,↑,↑,↑,↑, →,↑,
↑,↑,↑,↑
9750.0
mm
10 Exit data set level, function, sub menu
and menu. Save configuration and
return to operating mode. ↵,↵,↵,↵ 6750
LEVEL mm
Gauges with two current outputs
Two outputs are required for displaying readings simultaneously for two separated products stored
in the tank. Set up a scale using user functions 1.3.1 to 1.3.4 as shown above to measure level, then
repeat the procedure for interface measurement using user functions 1.3.5 to 1.3.8. Give some
thought to where the minimum and maximum points for each scale should be.
Setting up a volume scale
Calibrate for volume measurement in submenu 1.7 then select “volume” as the scale parameter.