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Thermocouple Accuracy Table by Type and Temperature

Hardware: Compact FieldPoint, CompactDAQ, CompactRIO, Multifunction DAQ (MIO), SCXI, SCC

Problem:
I am reading the temperature of a chamber using two thermocouple of the same type but the readings are different. I have calculated the accuracy of my measurement hardware but it does not compensate for the difference in readings. What may be causing this phenomenon?

Solution:
In addition to considering the accuracy of the measurement hardware, you should consider the inherent accuracy of the thermocouple. The accuracy of a thermocouple is effected by its type and temperature. See the table below for the maximum permitted error (in degree Celsius) for various common thermocouples that comply with IEC 584-2 (1982).

Temperature
B Type
E Type
J type
K Type
N Type
R Type
S Type
T Type
-200
-
-
-
3.0
3.0
-
-
3.0
-100
-
-
-
2.5
2.5
-
-
1.5
0
-
1.7
1.5
1.5
1.5
1.0
1.0
0.5
200
-
1.7
1.5
1.5
1.5
1.0
1.0
0.8
400
-
2.0
1.6
1.6
1.6
1.0
1.0
-
600
1.5
3.0
2.4
2.4
2.4
1.0
1.0
-
800
2.0
4.0
-
3.2
3.2
1.0
1.0
-
1000
2.5
-
-
4.0
4.0
1.0
1.0
-
1200
3.0
-
-
9.0
9.0
1.3
1.3
-
1400
3.5
-
-
-
-
1.9
1.9
-
1600
4.0
-
-
-
-
2.5
2.5
-

Related Links:
International Electrotechnical Commission (IEC) - Standards organization responsible for thermocouple accurcay standard IEC 584-2.

Attachments:





Report Date: 02/06/2007
Last Updated: 03/14/2008
Document ID: 465HI1BH

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