KROHNE LEVEL-SONIC BM90 Series Installation And Operating Instructions Manual page 39

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.
Point Head (cm)
1.00 0 . 0
2.00 2 . 5
3.00 5 . 0
4.00 7 . 5
5.00 10.0
6.00 15.0
7.00 20 0
8.00 25.0
9.00 30.0
10.00 Not used
11.00 Not used
12.00 Not used
13.00 Not used
14.00 Not used
15.00 Not used
16.00 Not used
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
( u p t o ' A 1 6 ) '
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.
% Head 'A' Value
0 . 0 0.00
8 . 3 8.00
16.70 17.00
25.0 25.00
33.30 33.00
50.0 50.00
66.60 67.00
83.20 83.00
100.0 100.00
Not used 255.00
Not used 255.00
Not used 255.00
Not used 255.00
Not used 255.00
Not used 255.00
Not used 255.00
Flow litres/sec
0 . 0
0 . 4
1 . 7
3 . 7
6 . 3
12.70
20.30
29.30
39.0
Not used
Not used
Not used
Not used
Not used
Not used
Not used
% o f l e v e l
1 0 0
9 0
8 0
7 0
6 0
5 0
4 0
3 0
2 0
1 0
0
Points ' A '
Number % Head or Level
1 0
2 10
3 20
4 30
5 40
6 50
7 60
8 70
9 80
10 90
11 100
12 110
13 255
14 255
15 255
16 255
% Flow 'b' Value
0 . 0 0
1 . 1 11
4 . 4 44
9 . 5 95
16.2 162
32.5 325
52.0 520
75.0 750
100.0 1000
Not used . 0
Not used . 0
Not used . 0
Not used . 0
Not used . 0
Not used . 0
Not used . 0
T r a n s d u c e r
V e s s e l ( o r c h a n n e l )
s y m m e t r i c a l
a b o u t c / 1
' b '
% of Flow of volume
0 . 0
0 . 0
7 . 2
16.1
27.3
37.5
48.5
59.5
70.5
80.0
89.5
100.0
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