System Temperature Error For The Dt9871 - Data Translation DT9871 User Manual

Appendix A

System Temperature Error for the DT9871

Table 11
temperature points over the dynamic range of the instrument.
Input
Temperature
–100C
0C
100C
300C
500C
700C
900C
1100C
1400C
a. Conditions for accuracy measurements:
MEASURpoint warm-up time of 1 hour. Inclusive of typical 0.2
Exclusive of thermocouple errors.
The histograms shown in
distribution for each of the available filter types on the DT9871. Note that converting V error
to temperature error depends on thermocouple type. For example, a K thermocouple changes
approximately 39 V per degrees C; therefore, a noise level of 10 V adds 0.3
(10 V / 39 V) for a type K thermocouple.
114
lists the typical accuracy of the DT9871 for each thermocouple type at several
Table 11: Typical Thermocouple Accuracy of the DT9871
J K T
0.33C 0.37C 0.38C
0.30C 0.33C 0.33C
0.31C 0.29C 0.31C
0.29C 0.34C 0.29C
0.28C 0.31C
-----------
0.27C 0.30C
-----------
0.27C 0.34C
-----------
0.28C 0.34C
-----------
----------- ----------- -----------
Figure 38
a
Thermocouple Type
E S
0.31C
-----------
0.28C 1.12C
0.27C 0.88C
0.26C 0.75C
0.26C 0.71C
0.27C 0.68C
0.28C 0.66C
0.64C
-----------
0.62C
-----------

C CJC error (maximum CJC error is 0.3
and Figure 39 characterize the Gaussian system noise
R B
0.44C
----------- -----------
1.14C 0.39C
-----------
0.86C 0.35C
-----------
0.71C 1.84C 0.33C
0.66C 1.20C 0.33C
0.63C 0.92C 0.33C
0.60C 0.8C 0.33C
0.58C 0.71C 0.34C
0.56C 0.64C
-----------

C).

C error
N