Datcon DT4120 PS Series, Руководство по эксплуатации

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DT4120 xx xx (PS)
36
20170324-V0
7.6. Pt1xx correction values (04. menu item)
Function The real Pt1xx characteristics may differ from the theoretical
R-°C curve. The difference will cause a measurement error
on temperature measurement. When you are capable to
calibrate the Pt1xx sensor on minimum 3 points you will
know the resistance difference of the theoretical and real
characteristics. Using this resistance values, the instrument
will correct the measurement error on this points exactly by
adding the correction values and - using interpolation
method - on all other points of the whole characteristics. For
the best curve fitting it is recommended to choose the
correction points at about 20%; 50%; 80% of the
measurement range.
Note: The accuracy of this correction method depends on
the accuracy of the calibrating instrument.
Example
Sequence of operation
Example:
The measurement range is 50 °C - 150 °C.
Calibrate the Pt100 sensor on the following temperatures:
70 °C; 100 °C; 130 °C.
1. Make a table according this:
Temperature
(°C) R n ominal
(ohm)
R m easured
(ohm)
Rn - Rm
(ohm)
70 127.08 126.76 0.32
100 138.51 138.49 0.02
130 149.83 149.91 -0.08
Use the bold resistance values for correction according the
following steps:
1. Enter the menu with the supervisor code.
The way the code should be type in can be found in
Chapter
7.1. Typing the code in . You see on the display:

.
2. Keep stepping by pressing the ▲ button as long as you
see this menu item:

.( Cor rection points =
correction points).