KROHNE BM 90 EN - Manual (Page 39)

39
Points ’A’ ’b’
Number % Head or Level % of Flow of volume
1 0 0.0
2 10 0.0
3 20 7.2
4 30 16.1
5 40 27.3
6 50 37.5
7 60 48.5
8 70 59.5
9 80 70.5
10 90 80.0
11 100 89.5
12 110 100.0
13 255 -
14 255 -
15 255 -
16 255 -
110
100
90
80
70
60
50
40
30
20
10
0
Vessel (or channel)
symmetrical
about c/1
Transducer
% of level
Point Head (cm) % Head ’A’ Value Flow litres/sec % Flow ’b’ Value
1.00 0.0 0.0 0.00 0.0 0.0 0
2.00 2.5 8.3 8.00 0.4 1.1 11
3.00 5.0 16.70 17.00 1.7 4.4 44
4.00 7.5 25.0 25.00 3.7 9.5 95
5.00 10.0 33.30 33.00 6.3 16.2 162
6.00 15.0 50.0 50.00 12.70 32.5 325
7.00 20 0 66.60 67.00 20.30 52.0 520
8.00 25.0 83.20 83.00 29.30 75.0 750
9.00 30.0 100.0 100.00 39.0 100.0 1000
10.00 Not used Not used 255.00 Not used Not used .0
11.00 Not used Not used 255.00 Not used Not used .0
12.00 Not used Not used 255.00 Not used Not used .0
13.00 Not used Not used 255.00 Not used Not used .0
14.00 Not used Not used 255.00 Not used Not used .0
15.00 Not used Not used 255.00 Not used Not used .0
16.00 Not used Not used 255.00 Not used Not used .0
NOTE: 1. Points 10 to 16 not used - leave at factory
default value.
2. ’A’ values must be whole numbers, no deci
mals allowed.
3. ’b’ values must be entered as the tabulated
value, the decimal will be automatically allocated.
Now continue programming the instrument as follows:
Programme the instrument exactly as section 4.5 on Page 31,
except:
Change Pr.45 from 2 to 4, which denotes
"Special Flow Device".
Go to Pr.44 and proceed as follows:
Press Pr.44 to display Pr.44:
Press ’DSP’ to show
Press ’ENT’ to show ’A1’
Press ’DSP’ to show value of ’A1’ (default = 255)
Key in the value ’O’ from Table 1 and press ’ENT’
Press ’DSP’ to show ’A1’ again
Press ’ s’ to show ’A2’
Press ’DSP’ to show value of ’A2’ (default = 255)
Key in the value ’8’ from Table 1 and press ’ENT’
Continue for all points which you need to use
(up to ’A16)’
Any points not used must be left at the default
of 255
Press ’DSP’ to display the last ’A’ number used, then
Press ’ t’ several times to return to ’A1’
Press # to show ’b1’
Press ’DSP’ to show value of ’b1’ (default = .0)
Key in the value ’0’ from Table 1 and press ’ENT’
Press ’DSP’ to show ’b1’ again
Press ’ s’ to show ’b2’
Press ’DSP’ to show value of ’b2’ (default = .0)
Key in the value ’11’ from Table 1 (accepted as 1.1)
Continue for all points which you need to use (up to 16)
Any points not used must be left at the default of .0
Press ’TEST’ then ’DSP’ to show Pr.44
Leave the linearisation part of the programme by dis
playing any other parameter, or go into ’RUN’ mode.
Example: Flow - Special Flume Mapping
Use Example 4.5 on Page 31, but substitute a special ’U’ throat flume with maximum flow
39 litres/second at 30 cm/hd.
First, create the following table from the relationship of head and flow which must be given forthe special flume.