Keithley 6430, Instruction Manual

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Performance Verification 18-3
Warm-up period
Allow the Model 6430 to warm up for at least one hour before conducting the veri fi cation
procedures.
If the instrument has been subjected to temperature extremes (those outside the ranges stated
above), allow additional time for the instrument ’ s internal temperature to stabilize. Typically,
allow one extra hour to stabilize a unit that is 10 ° C (18 ° F) outside the speci fi ed temperature
range.
Also, allow the test equipment to warm up for the minimum time speci fi ed by the
manufacturer.
Line power
The Model 6430 requires a line voltage of 100 to 240V and a line frequency of 50 or 60Hz.
Veri fi cation tests must be performed within this range.
Recommended test equipment
Table 18-1 summarizes recommended veri fi cation equipment. You can use alternate equip-
ment as long as that equipment has speci fi cations at least as good as those listed in Table 18-1.
Keep in mind, however, that test equipment uncertainty will add to the uncertainty of each mea-
surement. Generally, test equipment uncertainty should be at least four times better than corre-
sponding Model 6430 speci
fi cations. Table 18-1 also lists the speci fi cations of the
recommended test equipment.
NOTE
Model 5156 Electrometer Calibration Standard uncertainty is less than four times
better than Model 6430 specifications. As a result, 1pA-100nA and 2G
Ω
-200G
Ω
range reading limits include Model 5156 uncertainty.
CAUTION Before testing the 20
Ω
and 200
Ω
ohms ranges, make sure your resistance
calibrator can safely handle the default test currents for those ranges
(100mA and 10mA for the 20
Ω
and 200
Ω
ranges, respectively). If not, use
the Model 6430 MANUAL ohms mode, and set the test current to the max-
imum safe calibrator current. Note that Model 6430 measurement accu-
racy is reduced and reading limits should be recalculated using the
additional uncertainty when using MANUAL ohms. See the specifications
in Appendix A for details.