Nonlin 6V; Non-Linear Analog Output Equations - Instrutech VGC301 User Manual

Instruction Manual
7.5

NONLIN 6V; Non-Linear Analog Output Equations

You may calculate the pressure represented by the NONLIN 6V, 0.375 to 5.659 V non-linear analog output voltage for the
"S-curve" using a multi-segment, n
equation defined for various pressure measurement ranges are given in the following table:
For Non-Linear Analog Output voltage range of 0.375 to 2.842 volts, use this table.
For Non-Linear Analog Output voltage range of 2.842 to 4.945 volts, use this table.
For Non-Linear Analog Output voltage range of 4.94 to 5.659 volts, use this table.
Where y(x) = pressure in Torr,
Example: Measured analog output voltage is 0.3840 V.
From first table shown above use equation:
2 3
y(x) = a + bx + cx + dx + ex
X = 0.3840 volts
A = -0.02585, b=0.03767, c=0.04563, d=0.1151, e=-0.04158, f=0.008738
y(x) = Pressure = 1.0E-03 Torr
The following tables in section 7.6
InstruTech, Inc.
th
order polynomial function calculation. The coefficients for the n
Coefficients for y(x) = a + bx + cx
a
b
c
d
e
f
Coefficients for
a
b
c
d
e
f
Coefficients for
a
b
c
d
x= measured analog output in volts
4 5
+fx
and section 7.7 are based on the equations listed above.
2 3 4 5
+ dx + ex +fx
-0.02585
0.03767
0.04563
0.1151
-0.04158
0.008738
0.1031
-0.3986
-0.02322
0.07438
0.07229
-0.006866
100.624
-0.37679
-20.5623
0.0348656
VGC301 Controller
th
order polynomial
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