7
Introductionandspecifications
Specifications
Table 3
Resistor stability specifications
Resistor (Rs) Accuracy (ppm of reading)
24 hours
30 days
1
W
5 ppm
10 ppm
10
W
0.5 ppm
2 ppm
25
W
0.25 ppm
1 ppm
100
W
0.2 ppm
1 ppm
10 k
W
0.25 ppm
1 ppm
Absolute resistance accuracy
Absolute resistance accuracy is the ability of the instrument to measure absolute resistance, Rx, using the
internal reference resistors. The following specifications apply using the given reference resistor, Rs, and
excitation current.
The 1-year specifications 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 verification is guaranteed for 99% confidence level, 1-year specifications within the specified
operating temperature range of 15°C to 30°C, maintaining a calibration interval of 6 months for the first year
and 1 year thereafter.
Table 4
Absolute resistance accuracy specifications
Resistance range (Rs, current)
Accuracy (ppm of reading)
95% confidence 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 k
W (
10 k
W
, 10
m
A)
Greater of 5 ppm or 0.000012 k
W
10 k
W
to 40 k
W
(10 k
W
, 10
m
A)
8 ppm
40 k
W
to 100 k
W (
10 k
W
, 2
m
A)
20 ppm
100 k
W
to 500 k
W (
10 k
W
, 1
m
A)
80 ppm
99% confidence 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 k
W
to 10 k
W (
10 k
W
, 10
m
A)
Greater of 6.3 ppm or 0.000015 k
W
10 k
W
to 40 k
W
(10 k
W
, 10
m
A)
10 ppm
40 k
W
to 100 k
W (
10 k
W
, 2
m
A)
25 ppm
100 k
W
to 500 k
W (
10 k
W
, 1
m
A)
100 ppm
Measurement current accuracy
Measurement current accuracy is guaranteed to meet the following specifications. The specifications are stated
as percent of selected current or in absolute mA.
