Humidity Verification Equipment; Verification Limits; Restoring Default Conditions; Table - Keithley 6517 Service Manual

Performance Verification
1.5.4 Humidity verification equipment
Table 1-4 summarizes test equipment recommended to ver-
ify the accuracy of the Model 6517A humidity measurement
function.

Table 1-4

Humidity verification equipment
Mfg. Model Description
Fluke 5700A DC voltage calibrator 0V, 0.5V, 1V,
Banana plugs to clip
leads
2, 1 in. lengths of
solid #20AWG wire
* DC voltage calibrator with better than 0.25% basic accuracy may be
substituted.
1.6 Verification limits
The verification limits stated in this section have been calcu-
lated using only Model 6517A one-year accuracy specifica-
tions, and do not include test equipment uncertainty. In cases
where the Model 6517A apparently does not meet its pub-
lished specifications based on stated reading limits, reading
limits should be recalculated using both Model 6517A accu-
racy specifications and the total absolute uncertainty of the
verification equipment.
Reading limit calculation example
As an example of how reading limits can be calculated using
test equipment uncertainty, assume that the 200µA range is
being tested using a 190µA input value, and the various spec-
ifications are as follows:
1-4
The calculated limits are:
Reading limits = 190µA ± [(190µA × 0.1% + 0.005µA) +
(190µA × 103ppm)]
Specifications*
Reading limits = 190µA ± 0.21457µA
Reading limits = 189.7854µA to 190.2146µA
±5ppm basic
accuracy
1.7
Before performing each performance verification procedure,
restore instrument bench default conditions as follows:
1. From the normal display mode, press the MENU key.
2. Select SAVESETUP, and press ENTER. The following
3. Select RESET, and press ENTER. The display will then
4. Select BENCH, then press ENTER. The following will
5. Press ENTER again to confirm instrument reset. The
• Model 6517A 200µA range one-year accuracy: ±(0.1%
of reading + 5 counts)
• Calibrator total absolute uncertainty at 190µA output:
±103ppm

Restoring default conditions

The instrument will display the following:
MAIN MENU
SAVESETUP COMMUNICATION CAL
will be displayed:
SETUP MENU
SAVE RESTORE POWERON RESET
appear as follows:
RESET ORIGINAL DFLTS
BENCH GPIB
be displayed:
RESETTING INSTRUMENT
ENTER to confirm; EXIT to abort
instrument will return to normal display with bench
defaults restored.