KROHNE C95 CI EN - Manual (Page 14)

S
SAvE
MA
SAvE
no YES
exit with confi-
guration saving
exit without
configuration
saving
revert to measure
display
4.5.1 Current input
•
Linear :
Features
Measurable input limits : -22 to 22 mA
• Unlinear :
Square root extraction
Note : The function square root extraction tends to amplify the input
signal background noise on getting near zero.
To avoid the ripples caused by this noise, just programme a cut-off value
(in display points), see p14 .
Special linearisation :
For specific applications such as volume measurements, the meter can
memorise an unlinear curve programmable in X and in Y.
4.5 IInput ffeatures aand pprogramming llimits
«
root
«
Caliber
Display
resolution
Input stage
resolution
Accuracy
from -20 to
+20mA
± 1 digit 16 bits 0.05% of MR
Li.SPE
«
The curve resulting from your equation can be replaced by a series of
linear segments, with a maximum of 20 points
(19 segments).
Note : The values of the abscises (x) have to go increasing d.in < value
of A01 < value of A02...< F.in.
Example :
Say a layed cylindric tank, 1 meter high (h) and 1 meter long (l). A linear
0-20 mA sensor measures the height of the liquid surface line :
Meter input : height h
0 meter -> 0 mA (empty tank)
1 meter -> 20 mA (full tank)
with cos β/2 = ( R - h ) / R
Sin β/2 = C/2R
Meter display :
Empty tank volume d.diSP = 0.000
Full tank volume F.diSP =0.785
Volume = L [
π
R² β/360 - C(R-h)/2]
Hence a curve of 10 equally long segments :
Etendue de mesure / nr of segments = 20mA/10 = 2mA length of
the segment. For 10 segments nb = 9 (11 points to be programmed,
including d.in and F.in).
Input
mA
d.in 0
A01
2
A02 4
A03 6
A04 8
A05 10
A06 12
A07 14
A08 16
A09 18
F.in
20
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0 0.00
73.74
106.26
132.84
156.93
180.00
203.07
227.16
253.74
286.76
360.00
0.00
0.60
0.80
0.92
0.98
1.00
0.98
0.92
0.70
0.60
0.00 0.000
0.041
0.112
0.198
0.293
0.393
0.492
0.587
0.674
0.745
0.785
d.diSP
B01
B02
B03
B04
B05
B06
B07
B08
B09
F.diSP
00.00
01.04
02.85
05.04
07.47
10.00
12.54
14.96
17.17
18.98
20.00
Height
m
Degree
Chord
m
Volume
m 3
Outps.
in mA
β
(R)
L (length)
C (chord)
R (ray)
h
(height)
Note : Exit from mode programming with configuration saving ( SAvE, YES ) will
automatically reset to zero the tare, the min. and max. and the recording of
alarms, as well as the pulse output buffers.
In case of modification of the decimal point location of the instant value or of
the totalizer, the instrument will propose after SAvE YES all the decimal point rela-
ted parameters which have not been modified.
A
SAvE YES will not reset the totalizer to zero. If its parameters have been chan-
ged it will have to be reset to zero, in order to avoid an incoherent counting
( see p22 ).
4.4.10 Programming exit with or without saving