National Instruments NI USB-TC01 Bedienungsanleitung Seite 11

Temperature Measurement Accuracy
© National Instruments Corporation
Input noise.............................................. 2 μVpp
Open thermocouple bias voltage............ 3.3 V
Cold-junction compensation
sensor accuracy
0 to 65 °C ........................................ 1.25 °C max, 0.6 °C typical
Cold-junction compensation
sensor resolution .................................... 0.0625 °C typical
Overvoltage protection........................... 30 V max between TC+ and TC–
Figures 9 through 16 show the errors for each thermocouple type when
connected to the NI USB-TC01. The figures display the maximum errors at
25 °C and over the full operating temperature range, and account for
cold-junction compensation errors. The figures were generated using
thermocouples connected to subminiature connectors of the same type.
The CJC sensor resolution is 0.0625 °C. This is the minimum value of the
CJC step width. As such, the reading may result in a saw tooth curve rather
than a square curve as the temperature inside the board changes. This is the
expected behavior.
6
4
2
0
–500
Figure 9. Temperature Error of Type J Thermocouple
Max Over Operating Temp
Max at 25 °C
0 500
Measured Temperature (C)
11 NI USB-TC01 User Guide and Specifications
3 3
1×10 1.5×10