Performance Verification
1-4
1.8
Verification procedures
The following paragraphs contain procedures for verifying
instrument accuracy specifications for the following measur-
ing functions:
• DC volts
• AC volts
• DC current
• AC current
• Resistance
• Frequency
• Temperature
NOTE
The following verification procedures are
intended to verify the accuracy of the
Model 2002 and include reading limits
based on the Model 2002 relative accuracy
specifications and the total uncertainty of
the recommended calibrator. DCV, DCI,
and ohms limits include factory calibra-
tion uncertainty.
If the Model 2002 is out of specifications and not under war-
ranty, refer to the calibration procedures in Section 2.
WARNING
The maximum common-mode voltage
(voltage between INPUT LO and chas-
sis ground) is 500V peak. Exceeding this
value may cause a breakdown in insula-
tion, creating a shock hazard. Some of
the procedures in this section may
expose you to dangerous voltages. Use
standard safety precautions when such
dangerous voltages are encountered to
avoid personal injury caused by electric
shock.
NOTE
Do not connect test equipment to the
Model 2002 through a scanner or other
switching equipment.
1.8.1 DC volts verification
DC voltage accuracy is verified by applying accurate DC
voltages from a calibrator to the Model 2002 input and veri-
fying that the displayed readings fall within specified ranges.
Follow the steps below to verify DCV measurement
accuracy.
CAUTION
Do not exceed 1100V peak between IN-
PUT HI and INPUT LO, or instrument
damage may occur.
1. Connect the Model 2002 to the calibrator, as shown in
Figure 1-1. Be sure to connect calibrator HI to Model
2002 INPUT HI and calibrator LO to Model 2002
INPUT LO as shown.
NOTE
Use shielded, low-thermal connections
when testing the 200mV and 2V ranges to
avoid errors caused by noise or thermal
offsets. Connect the shield to calibrator
output LO.
2. Turn on the Model 2002 and the calibrator, and allow
a four-hour warm-up period before making
measurements.
3. Restore Model 2002 factory default conditions, as
explained in paragraph 1.7.
4. Set Model 2002 operating modes as follows:
A. From normal display, press CONFIG then DCV.
B. Select SPEED, then press ENTER.
C. Select HIACCURACY, then press ENTER.
D. Select FILTER, then press ENTER.
E. Select AVERAGING, then press ENTER.
F. Using the cursor and range keys, set the averaging
parameter to 10 readings, then press ENTER.
G. Press EXIT to return to normal display.
5. Select the Model 2002 200mV DC range. (If the FILT
annunciator is off, press the FILTER key to enable the
filter.)
NOTE
Do not use auto-ranging for any of the ver-
ification tests because auto-range hystere-
sis may cause the Model 2002 to be on an
incorrect range.