Keithley 2000, Calibration Manual, Page: 14 / 88

Verification limits
The verification limits stated in this section have been calculated using only the Model 2000
one-year accuracy specifications, and they do not include test equipment uncertainty. If a par-
ticular measurement falls slightly outside the allowable range, recalculate new limits based on
both Model 2000 specifications and pertinent calibration equipment specifications.
Example reading limit calculation
The following is an example of how reading limits have been calculated:
Assume you are testing the 10V DC range using a 10V input value. Using the Model 2000
one-year accuracy specification for 10V DC of ± (30ppm of r 5ppm of range), the cal-
culated limits are:
Reading limits = 10V ± [(10V
×
30ppm) + (10V
×
5ppm)]
Reading limits = 10V ± (.0003 + .00005)
Reading limits = 10V ± .00035V
Reading limits = 9.99965V to 10.00035V
Restoring factory defaults
Before performing the verification procedures, restore the instrument to its factory defaults
as follows:
1. Press SHIFT and then SETUP. The instrument will display the following prompt:
RESTORE: FACT
NOTE Pressing either range key toggles the RESTORE selection between USER and FACT.
2. Restore the factory default conditions by pressing ENTER.
3. Factory defaults will be set as follows:
Speed: medium
Filter: 10 readings
Performance Verification 1-5