WIKA DI25 Betriebsanleitung Seite 12

Character factory default
Input value correction
Input value can be corrected in [sensor correction coefficient] and [sensor correction].
In [sensor correction coefficient], set the slope of temperature change.
In [sensor correction], set the difference between temperatures before correction and after correction.
PV after input correction is expressed by the following formula.
PV after input correction = current PV x sensor correction coefficient + (sensor correction value)
The following shows an example of input value correction using 'sensor correction coefficient' and 'sensor
correction value'.
After correction
(1) Select any 2 points of PV to be corrected, and determine the PV after correction.
PV before correction: 300
PV before correction: 750
(2) Calculate sensor correction coefficient from step (1).
(Y' – X') / (Y – X) = (700 – 340) / (750 - 300) = 0.8
(3) Enter a PV value of 300
(4) Set step (2) value as a sensor correction coefficient.
(5) Read the PV. 240
(6) Calculate the sensor correction value. Calculate the difference between 'PV after correction' and Step (5)
PV.
340 – 240 = 100
Sensor correction
• This corrects the input value from the sensor.
When a sensor cannot be set at the exact location where measurement
is desired, the sensor-measured temperature may deviate from the
temperature in the measurement location. When using multiple
indicators, sometimes the measured temperatures do not match due to
differences in sensor accuracy or installation site.
In such a case, the temperature in the installation site can be adjusted to
the desired temperature by adjusting the sensor input value.
PV after sensor correction= Current PV x (sensor correction coefficient)
+(sensor correction value)
Refer to 'input value correction' (p.12).
• Setting range: -1000.0 to 1000.0
Direct current, DC voltage input: -10000 to 10000 (The placement of the
decimal point follows the selection.)
750
700
X'
340
X
300
Corrected from 300
to 340 .
300
Slope before correction
Slope after correction
PV after correction: 340
PV after correction: 700
using an mV generator or dial resistor.
will be indicated.
Setting item, function, setting range
( )
Y
Y'
Corrected from 750
Before correction
750
12
to 700 .
(Fig. 5.3-1)