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APPENDICES
Appendix 1 Accuracy
APPENDICES
Appendix 1 Accuracy
This section describes the accuracy of a temperature input module.
Accuracy of the thermocouple input module
The accuracy () is calculated from the following formula.
A
C
+ T
C
C
OAT
+ A
CJ
Note that the operating ambient temperature change indicates the extent to which the operating ambient temperature is out of
the range of 255.
Accuracy when B thermocouple is used, the operating ambient temperature is 35, and measured temperature is 1000
(1.0) + (0.29) (35 - 30) + (1) = 3.45
■Usable thermocouple, conversion accuracy, and effect per wiring resistance 1Ω
The following table shows the relation of usable thermocouple, conversion accuracy, and effect per wiring resistance 1
A
C
: Conversion accuracy
T
C
: Temperature characteristics
C
OAT
: Operating ambient temperature change
A
CJ
: Cold junction compensation accuracy
Usable
thermocouple
Temperature
measuring
range
*1
Conversion accuracy
(for operating ambient
temperature 255)
Temperature characteristics
(for 1 of operating ambient
temperature change)
Maximum
temperature
error at ambient
temperature 55
Effect per wiring
resistance 1
*4
B0 to 600
*3
*3
*3
*3
600 to 800
*2
1.3 0.3 8.8 0.042/
800 to 1700
*2
1.0 0.29 8.25 0.036/
1700 to 1820
*3
*3
*3
*3
R -50 to 0
*3
*3
*3
*3
0 to 300
*2
1.5 0.4 11.5 0.05/
300 to 1600
*2
0.8 0.29 8.05 0.028/
1600 to 1760
*3
*3
*3
*3
S -50 to 0
*3
*3
*3
*3
0 to 300
*2
1.5 0.4 11.5 0.05/
300 to 1600
*2
0.8 0.29 8.05 0.028/
1600 to 1760
*3
*3
*3
*3
K -270 to -200
*3
*3
*3
*3
-200 to 0
*2
0.5 0.06, or a larger value of -0.1% or
+0.1% of measured temperature
5.5 0.017/
0 to 1200
*2
0.3 0.06, or a larger value of -0.02%
or +0.02% of measured temperature
6.3 0.007/
1200 to 1370
*3
*3
*3
*3
E -270 to -200
*3
*3
*3
*3
-200 to 0
*2
0.5 0.06, or a larger value of -0.15%
or +0.15% of measured temperature
8.0 0.01/
0 to 900
*2
0.2 0.06, or a larger value of -0.02%
or +0.02% of measured temperature
4.7 0.005/
900 to 1000
*3
*3
*3
*3
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