Performance Verification
1-2
1.4
Line power
The Model 2002 should be tested while operating from a line
voltage in the range of 90–134V or 180–250V at a frequency
of 50, 60, or 400Hz.
1.5
Recommended test equipment
Table 1-1 lists all test equipment required for verification.
Alternate equipment may be used as long as that equipment
has specifications at least as good as those listed in the table.
NOTE
The calibrator listed in Table 1-1 is suffi-
ciently accurate to verify Model 2002
accuracy to total factory calibration uncer-
tainty. It is not accurate enough to verify
Model 2002 relative accuracy specifica-
tions alone.
1.6
Verification limits
The verification limits stated in this section have been calcu-
lated using the Model 2002 one-year relative accuracy spec-
ifications and the total absolute uncertainty of the factory
recommended calibrator (see Table 1-1). DCV, DCI, and
ohms limits also include factory calibration uncertainty. (See
specifications.) Those who are using calibration sources with
better absolute uncertainty should recalculate the limits us-
ing the Model 2002 relative accuracy specifications, the ab-
solute uncertainty specifications of the calibration sources,
and factory calibration uncertainty (DCV, DCI, and ohms).
1.6.1 Reading limit calculation example
As an example of how reading limits are calculated, assume
that the 20VDC range is being tested using a 19V input val-
ue, and the various specifications are as follows:
• Model 2002 relative accuracy: ±(10ppm of r
0.15ppm of range)
• Model 2002 factory calibration uncertainty: ±2.6ppm
of reading
• Calibrator total absolute uncertainty at 19V output:
±5.4ppm
The calculated limits are:
Reading limits = 19V ± [(19V
×
(10ppm + 2.6ppm)) + (20V
×
0.15ppm) + 19V
×
5.4ppm]
Reading limits = 19V ± 0.000345V
Reading limits = 18.999655V to 19.000345V
1.6.2 Additional derating factors
Certain functions and ranges are subject to certain derating
factors that must be included when calculating reading
limits. For example, coupling errors must be added to low-
frequency AC limits, while AC voltage limits for inputs
above 100V are subject to additional derating factors.
Always read the associated specification notes to determine
if any derating factors apply before calculating reading
limits.
1.7
Restoring default conditions
Before performing each performance verification procedure,
restore instrument bench default conditions as follows:
1. From the normal display mode, press the MENU key.
The instrument will display the following:
MAIN MENU
SAVESETUP GPIB CALIBRATION
2. Select SAVESETUP, and press ENTER. The following
will be displayed:
SETUP MENU
SAVE RESTORE POWERON RESET
3. Select RESET, and press ENTER. The display will then
appear as follows:
RESET ORIGINAL DFLTS
BENCH GPIB
4. Select BENCH, then press ENTER. The following will
be displayed:
RESETTING INSTRUMENT
ENTER to confirm; EXIT to abort
5. Press ENTER again to confirm instrument reset. The in-
strument will return to the normal display with bench
defaults restored.