User manual - METER SWE-N55L
Figure. 9.4 Example of user defined characteristic
9.2.
EXAMPLES OF CALCULATIONS
Example 1: Selection of the permissible input range (“4-20” mode)
If the user sets
“Lo r”
= 20,0% and
“Hi r”
= 10,0%, then permissible input currents
range will be equal: 3,2 mA ÷ 22 mA. Lower border of the range is the result of calculations:
4 mA - 4 mA × 20%, and the higher : 20 mA + 20 mA × 10%.
Example 2: The normalized I
n
result calculation
The normalized I
n
result is calculated accordingly to the expression on page 23, so if I
in
= 10
mA then 10 mA - 4 mA = 6 mA, and this result should be divided by the width of input range
(16 mA). Finally the normalized result: I
n
= 6/16 = 0,375.
In case when input current exceeds nominal measurement range, calculations are similar. For
example if input current is equal 2,5 mA then I
n
= (2,5 - 4)/16
≅
-0,0938, and if input current is
equal 20,5 mA then I
n
= (20,5 - 4)/16
≅
1,0313.
Example 3: The linear characteristic
Let parameters
“Lo C”
and
“Hi C”
equal to -300 and 1200 respectively. The calculations will
be done for three different input currents from example 2.
26
D
is
pl
ay
ed
v
al
ue
Prąd wejściowy [mA]
4
7.2
10.4
13.6
16.8
20
Y (PH)
0
0,2
0,35
0,5
0,7
1
0,9
Y (PL)
X = “20.0.”
X = “35.0.”
X (PL) = “50.0.”
X (PH) = “70.0.”
X = “90.0.”
X = “100.0.”
Input current [mA]
Normalized measurement I
n
(for 4-20 mA range)
5-elements characteristic
Summary of Contents for SWE-N55L
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