Yokogawa Data Acquisition with PID Control CX2000 - Manual (Page 35)

1-23
IM 04L31A01-01E
Explanation of Functions
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Bias
This function is used to add a constant value (bias value) to the PV and use the result in
the display of the PV and control.
PV input value + Bias value Process value in the instrument =
This function can be used in a case when the PV is less than the true value by a
constant amount due to the physical circumstances of the detector. For example, the
atmospheric temperature inside a furnace can be measured and substituted for the
material temperature. This function can also be used to make minute adjustments when
the displayed value is within the allowable precision range but small deviation exists
between other instruments and you wish to align it.
Selectable range: –100.0% to 100.0% of the measurement span (the initial value is 0.0%)
Ten-segment Linearizer Biasing Function
This function is used when you wish to correct the input value due to the deterioration of
the sensor. In the ten-segment linearizer biasing function, the output value (b) is the
corrected value obtained by adding the bias at numerous arbitrary points (up to 11 points
can be specified) against the input value (a), as shown in the figure below. For
definitions of the engineering units (EU and EUS), see appendix 8, “Explanation of
Engineering Units (EU and EUS).”
Selectable range of input values: EU (–5.0% to 105.0%) of the measurement span (the
initial value is 0.0%)
Selectable range of output values: EUS (–100.0% to 100.0%) of the measurement span
(the initial value is 0.0%)
Actual input
Ten-segment linearizer bias
Corrected value
(sum of the actual input
and the ten-segment
linearizer bias)
n.a2 n.a4 Input
(a)
n.b4
Output
(b)
Ten-segment Linearizer Approximation
This function is used when the relationship between the input signal value and the value you wish
to measure is not linear such as the level meter and the volume of a spherical tank. In the ten-
segment linearizer approximation function, you can set the output value (b) to an
arbitrary value with respect to the input value (a) of an arbitrary point (up to 11 points can
be specified), as shown in the figure below. For definitions of the engineering units (EU
and EUS), see appendix 8, “Explanation of Engineering Units (EU and EUS).”
Selectable range of input value:
EU (–5.0% to 105.0%) of the measurement span (the
initial value is 0.0%)
Selectable range of output values: EU (–5.0% to 105.0%) of the measurement span (the
initial value is 0.0%)
1.4 PV Input Related Settings