IMSRM02-E6
75
7. FUNCTIONS
7.1 Inputs
(1) PV bias
The value set in the PV bias is added to the actual input value to correct the input value.
The PV bias is used to correct the individual variations in the sensors or when there is difference
between the measured values (PV) of other instruments.
[Example]
When the temperature is measured by two instruments.
When the measured values (PV) are as shown in the
diagram:
CH1 = 200
°
C
CH2 = 198
°
C
If a PV bias correction value of +2
°
C is added to the
measured value of CH2, the displayed value will
become:
Displayed value = measured value (PV) + PV bias
= 198
°
C + 2
°
C = 200
°
C
In this instrument, for a span of 400
°
C, the PV bias
should be set to:
PV bias = 0.5 %
(400
×
0.5 % = 2
°
C)
(2) Temperature rise completion function
During the sampling of temperature input, when the measured temperature value (PV) comes within
the temperature rise completion range, the temperature rise completion will occur. Further in
considering the case that where the temperature rise completion range has been set in a narrow range,
etc., even if the measured temperature value (PV1) passes through the temperature rise completion
range in the time between the sampling periods (Previous sampling period - This time sampling
period), it is also judged as the temperature rise completion.
But it is only limited to the channel which is the object of the judgement.
PV1
PV2
Sampling period
Previous sampling
This time sampling
Set value (SV)
Temperature
rise
completion
+
−
CH1
CH2
PV1 = 200
°
C
PV2 = 198
°
C
