ICS Schneider Messtechnik WIKA EGS80, Operating Instructions Manual

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2018-12
20
Trip Amplifier EGS80X002001
Editing Device Data: Input
Example 2: selected unit °C, 0 °C to -100 °C is to correspond to 20 mA to 0 mA
• Linearization
y = m x + n
• Conversion factor = rise in the graph
m = (y2 – y1) / (x2 – x1)
m = (100 – 0) / (20 – 0) = 5
• Zero point = intersection point with the x-axis on the graph, with the condition that the physical
measuring range starts from 0 (y = 0 °C). The zero point corresponds to the upper measuring range
limit (x = 20 mA) at which the measuring range ends.
The zero point can be calculated as follows:
n = y – m x
n = -100 – 5 x 0 = -100
y = m x + n
x = (y – n) / m
x = (0 + 100) / 5 = 20
1 2 3 4 5 6 7 8 9 10
-1
50
100
150
200
-200
-150
-100
-50
-2 -3 -4
11 12 13 14 15 16 17 18 19 20
x [mA]
y [°C]