7
Introduction and Specications
Specications
Table 3 Resistor Stability Specifications
Resistor (Rs) Accuracy (ppm of reading),
95% condence level
24 hours 30 days
1W5 ppm 10 ppm
10W0.5 ppm 2 ppm
25W0.25 ppm 1 ppm
100W0.2 ppm 1 ppm
10kW0.25 ppm 1 ppm
2.2.2.3 Absolute Resistance Accuracy
Absolute resistance accuracy is the ability of the instrument to measure absolute resistance, Rx, using the
internal reference resistors. The following specications apply using the given reference resistor, Rs, and
excitation current.
The 1-year specications include calibration uncertainty, reference resistor drift, ambient temperature sensitiv-
ity, resistance ratio uncertainty, and measurement noise using 1-minute average and a 2-second sample period
(n = 30).
Performance verication is guaranteed for 99% condence level, 1-year specications within the specied
operating temperature range of 15°C to 30°C, maintaining a calibration interval of 6 months for the rst year
and 1 year thereafter.
Table 4 Absolute Resistance Accuracy Specifications
Resistance range (Rs, current) Accuracy (ppm of reading)
95% condence level, 1-year
0W to 1.2W (1W,10mA) Greater of 40 ppm or 0.000012W
0W to 12W (10W,3mA) Greater of 10 ppm or 0.000024W
0W to 120W (25W, 1mA) Greater of 5 ppm or 0.000024W
0W to 400W (100W, 1mA) Greater of 4 ppm or 0.00008W
0 W to 10 kW (10 kW, 10mA) Greater of 5 ppm or 0.000012kW
10 kW to 40 kW (10 kW, 10mA) 8 ppm
40 kW to 100 kW (10 kW, 2mA) 20 ppm
100 kW to 500 kW (10 kW, 1mA) 80 ppm
99% condence level, 1-year
0W to 1.2W (1W, 10 mA) Greater of 50 ppm or 0.000015W
0W to 12W (10W, 3 mA) Greater of 13 ppm or 0.00003W
0W to 120W (25W, 1 mA) Greater of 6.3 ppm or 0.00003W
0W to 400W (100W, 1 mA) Greater of 5 ppm or 0.0001W
0 kW to 10 kW (10kW, 10mA) Greater of 6.3 ppm or 0.000015 kW
10 kW to 40 kW (10kW, 10mA) 10ppm
40 kW to 100 kW (10kW, 2mA) 25ppm
100 kW to 500 kW (10kW,1 mA) 100ppm
2.2.2.4 Measurement Current Accuracy
Measurement current accuracy is guaranteed to meet the following specications. The specications are stated
as percent of selected current or in absolute mA.