Keithley 1801, Инструкция по эксплуатации, Страница: 53 / 93

Performance Verification
4-6
4.8.2 AC volts verification
AC voltage accuracy is checked by applying an accurate
AC voltage at 100Hz from an AC calibration source and
then verifying that the Model 1801 AC voltage reading
falls within the specified range.
CAUTION
Do not exceed 1V peak between IN-
PUT HI and INPUT LO, or preampli-
fier damage may occur. (Inputs over
2mV peak will require a one-minute
recovery period.)
1. Turn on the Model 2001 and calibrator, and allow a
two-hour warm-up period before making
measurements.
2. Connect the calibrator to the Model 1801 input, as
shown in Figure 4-2.
3. Restore Model 1801 factory default conditions, as
explained in paragraph 4.7.
4. Select the AC + DC coupling mode as follows:
A. Press CONFIG ACV, select COUPLING, then
press ENTER.
B. Select AC+DC, then press ENTER.
C. Press EXIT to return to normal display.
5. Select the ACV function, and make sure that REL is
disabled.
NOTE
Do not use REL to null offsets when per-
forming AC volts tests.
6. Set the calibrator output to 450.000µV AC RMS at a
frequency of 100Hz, and allow the reading to settle.
7. Verify that the Model 2001 reading is within the lim-
its summarized in Table 4-3.
4.8.3 Resistance verification
Model 1801 resistance accuracy specifications are derived
from Model 2001 current source accuracy as well as
Model 1801 DC volts measurement accuracy. As long as
the Model 2001 ohms and DC volts functions, and the
Model 1801 DC volts function meet their respective accu-
racy specifications, preamplifier ohms function accuracy
is automatically verifie, and it is not necessary to sepa-
rately verify measurement accuracy of the Model 1801
ohms function. See the Model 2001 Calibration Manual
for multimeter verification procedures.
Table 4-3
Limits for AC voltage verification
1801
range Calibrator
voltage Allowable readings
(1 year, 23 ±5°C)
500µV 450.000µV RMS
@ 100Hz 422.500µV to
477.500µV
Note: Limits shown do not include calibrator uncertainty.