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NI 4071 7½-Digit FlexDMM Calibration Procedure
4-Wire Resistance
Note
Tolerances are relative to the reported calibrator resistance value. For
example, the following values and equations demonstrate the 4-wire verification
tolerance calculations at 10 M
Ω
.
Table 22.
Example of 4-wire Verification Tolerance Calculations at 10 M
Ω
Parameter
Value
Fluke 5720A nominal value
10 M
Ω
Fluke 5720A displayed value
10.10604 M
Ω
NI 4071 range
10 M
Ω
NI 4071 two-year specification in
ppm of calibrator resistance
90 ppm
NI 4071 two-year specification in
ppm of range
10 ppm
Tolerance in M
Ω
(10.10604 * 90 / 1,000,000) + (10 * 10 / 1,000,000)
= 0.00101
Lower limit
10.10604 – 0.00101 = 10.10503 M
Ω
Upper limit
10.10604 + 0.00101 = 10.10705 M
Ω
