Fluke 1595A - Manual (Page 18)

1594A/1595A Super-Thermometer
Specifications
8
Table 5 Measurement Current Accuracy Specifications
Current Range Accuracy
99% confidence level, 1-year
0.001 mA to 0.005 mA
0.00005 mA
0.005 mA to 0.02 mA 1 %
0.02 mA to 0.2 mA 0.5 %
0.2 mA to 2 mA 0.2 %
2 mA to 20 mA 0.5 %
2.2.3 Ancillary Specifications
2.2.3.1 Temperature Measurement Noise
Temperature measurement noise indicates typical measurement noise in temperature measurements. The speci-
fications below are given for averages taken over a period of 1 minute with a 2-second sample rate. The effect
of noise may be reduced for longer averages or may be greater for shorter averages.
Noise performance is dependent upon many conditions. Some of the most important things to consider are the
type of thermometer, setup, and environmental conditions such as electromagnetic interference.
Due to the subjective nature of measurement noise, it is not a guaranteed specification. The specifications
listed in the table below are obtainable in a typical laboratory environment. It is important that the user make
their own evaluation of measurement noise in the application and environment where the Super-Thermometer
is used.
Table 6 Temperature Measurement Noise Specifications
Conditions (Rs, Current)
Standard Error
of the Mean, °C
Typical performance
25 W SPRT at 0°C (25 W, 1.0 mA)
0.00002
25 W SPRT at 420°C (25 W, 1.0 mA) 0.00006
100 W PRT at 0°C (100 W, 1.0 mA) 0.00001
100 W PRT at 420°C (100 W, 1.0 mA) 0.00003
10 kW Thermistor at 25°C (10 kW, 10 mA) 0.000003
2.2.3.2 Relative Measurement Current Accuracy
Zero-Power resistance values are calculated based on measurements taken at two levels of excitation current
that differ by a factor of 1.4142. Only the portions of the errors in the currents that are uncorrelated contribute
to error in the zero-power resistance value.
The following specifications may be used to estimate the contribution of current error in zero-power resistance
measurements.
Table 7 Relative Measurement Current Specifications
Range Relative Accuracy, mA
99% confidence level
0.001 mA to 0.1 mA
0.0008
0.1 mA to 2 mA 0.003
2 mA to 20 mA 0.03