Fluke 2680A User Manual page 220

2680A/2686A
Users Manual
Temperature
-200 °C
0 °C
100 °C
300 °C
600 °C
FAI Module Thermocouple per ITS-1990 Measurement Specifications
The following tables provide FAI Module specifications for the thermocouple
measurement function per ITS-1990.
Table A-33. FAI Module Thermocouple General Specifications
Specification
Input Impedance
Open Thermocouple Detect
Temperature Coefficient
Accuracy at -20 °C
A-24
Table A-32. FAI Module 4-Wire RTD Specifications
Resolution
Slow Fast
0.03 °C 0.06 °C
0.03 °C 0.06 °C
0.03 °C 0.06 °C
0.03 °C 0.06 °C
0.03 °C 0.06 °C
100 MΩ minimum in parallel with 300 pF
Operates by injecting a small ac signal into the input after
each measurement. A thermocouple resistance greater than
1 kΩ to 10 kΩ is detected as an open input.
To calculate Thermocouple accuracy for temperatures
between 28 °C and 60 °C, or -10 °C and 18 °C, use a linear
interpolation between the two applicable points. For example,
if the applicable specification at 28 °C is 0.6 and the
specification at 60 °C is 1.1, then the specification at 40 °C is
=(1.1-0.6)x(40-28)/(60-28)+0.6=0.7875.
Multiply the -10 °C to +60 °C accuracy specification by 2.
After 1 hour warm-up. For accuracy between -10 °C and
-20 °C, interpolate linearly.
Accuracy, 3σ + °C
90 Day
18 °C to 28 °C
Slow Fast
0.16 °C 0.25 °C
0.20 °C 0.31 °C
0.23 °C 0.34 °C
0.30 °C 0.41 °C
0.53 °C 0.63 °C
Characteristic
1 Year 1 Year
18 °C to 28 °C -10 °C to 60 °C
Slow Slow
0.25 °C 0.62 °C
0.31 °C 0.85 °C
0.34 °C 0.95 °C
0.41 °C 1.18 °C
0.63 °C 1.62 °C
Fast
1.10 °C
1.30 °C
1.40 °C
1.70 °C
2.12 °C