Level Pro ITC 450, User Manual

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where W means the displayed value.
Showed above expression is not valid when normalized result is negative. It is possible for 4-20 mode
only. In this case (In<0) the displayed result is equal “Lo C” (see graphs below).
10.1.3. Square root characteristic
The normalized result is rooted and further conversion is done as for linear characteristic. Conversion is made
accordingly with the expression:
I ,
10.1.4. User defined characteristic
where Y(PH), X(PH), Y(PL), X(PL) mean values of X and Y coordinates of PH i PL points.
If the normalized result exceeds the user defined characteristic values, then specific utmost segment,
defined by two next points, is used for calculations. If characteristic from figure below is used, and if
I
n
>1 then segment defined by points X(PL) = “90.0.” , X(PH) = “100.0.” will be used.
User defined characteristic is defined as set of X-Y points. Number of the points is variable and may be set
from 2 to 20 points which make linear segments (see graph and see Menu ”inPt” ). Due to the normalized
result I
n
, the device computes specific segment, e.g. for characteristic from figure below, and I
n
= 0,65 the
segment between points X =
”50.0.”
and X =
”70.0.”
will be chosen.
Let's mark those points as PL (point low) i PH (point high) - in this example PL= “50.0,” and PH = “70.0.” , and
the normalized result I
n
for the point PL as I
p
(in this example I
p
= I
n
(PL) = 0,5). The displayed result is
calculated accordingly to the expression:
Figure. 10.3 Normal („Lo C” < ”Hi C) and inverted („Lo C” > ”Hi C) characteristic
Input current [mA]
0 4 8 12 16 20
Input current [mA]
0 4 8 12 16 20
Y Y
X X
Y I
n p
40
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