Rockwell Automation 937CU-AITXF-DC1 Transmitter Supply Converter Installation Instructions - Manual (Page 20)

Bul. 937C Transmitter Supply Converter Installation Instructions
•
y = m x + n
• Conversion factor = rise in the graph
m = (y2 – y1) / (x2 – x1) m
= (4 - 0) / (20 – 12) = 0.5
• Zero point = intersection point with the x-axis on the graph (bar value at y = 0)
n = y – m x
n = 4 – 0.5 x 20 = -6
y = m x + n
x = (y – n) / m
x = (0 + 6) / 0.5 = 1
7 9 8 6 5 4 3 2 1 10 x [mA] -1
1
2
3
4
-4
-3
-2
-1
-4 -3 -2 11 12 13 14 15 16 17 18 19 20
y [bar]
Editing device data: Input
Example 3: selected unit bar, -4 bar ... 4 bar is to correspond to 4 mA ... 20 mA
18
Linearization