Warm-Up Period - Keithley 6430 Instruction Manual

Warm-up period

Allow the Model 6430 to warm up for at least one hour before conducting the verification
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 specified temperature
range.
Also, allow the test equipment to warm up for the minimum time specified by the
manufacturer.
Line power
The Model 6430 requires a line voltage of 100 to 240V and a line frequency of 50 or 60Hz.
Verification tests must be performed within this range.
Recommended test equipment
Table 18-1 summarizes recommended verification equipment. You can use alternate equip-
ment as long as that equipment has specifications 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 specifications. Table 18-1 also lists the specifications of the
recommended test equipment.
NOTE
CAUTION
Model 5156 Electrometer Calibration Standard uncertainty is less than four times
better than Model 6430 specifications. As a result, 1pA-100nA and 2GΩ-200GΩ
range reading limits include Model 5156 uncertainty.
Before testing the 20Ω and 200Ω ohms ranges, make sure your resistance
calibrator can safely handle the default test currents for those ranges
(100mA and 10mA for the 20Ω and 200Ω 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.
Performance Verification 18-3