Keithley 485 Instruction Manual page 11

PERFORMANCE VERIFICATION USING
MODEL 263 ~LIBRATOR/SOURCE
Use of the Model 263 to verify ac~aq specifications of
the Model 485 stip~ies the prored~ by etiating the
need for user desi~ed _nt somces. The quipment
fisted h Table >1 of the manual is not needed.
Idetiy performance verification shotid be perfomed
when the tis~ent k first received to emm that no
daage or chmge h calibration has ocmed dtig ship
ment. It may&O be perfomed when fi~ent acwa~
is swpe~ Orfo~w~ c~bration. E perfmrnance on any
of the rmges ia outside the specified tits, ctibrate the
titiment.
NOTE
Mthe
~ent does not meti spedicatiom md
is stfl under warrmty ~ess thm Q months stice
date of shipment), con~d your ~lMey mpmsen-
tative Orthe factory b detetie the atimr to &
t&en.
Etimenti Condltiom
M measurements shodd be made at m mbient
temperature b~een M" md 28°C (&" to 82°~ with a
relatiw humidity less thm 70°h.
Irritid
Conditimra
Before perfofig the verification procedure, m&e sure
the Models 485 md 263 meet the fo~owtig conditiom:
1 E the tis~ents have been subjed b tempmams
blow M°C (&°F) Orabom 28°C (82°F), dow sufficient
tie for the titruments to reach temperahs tithti
the rmge. GenerWy, it tskes one hour to stabtie m
irrs~ent that is M"C (MOF)outside of the specfied
range.
2. Tm on the Models 485 and 263, and allow them to
wm up for one hour. The Model ~ may be operated
from either ~ie power or battery pack power, as long
as the batteq pack has been fu~y charged..
Veficatirur Prncedw
Weed as fo~ows to verify the accuraq of the Model 485:
1. On the Model 485, press ZERO CHECK and select the
M rmge.
2. With an open input, adjust the ZERO pot for .0000 *1
cmrnt on the display.
3. Comect the Model 263 to the Model 485 as shown in
Fi~e 1. Make sue the cdlbrator is in standby.
4. Relesae ZERO CHECK on the Model 485.
5. Using the AMPS (adive) c~nt source, program the
Model 263 to output 1.90~nA and verify that the
reading is within the Itits h Table 1,
6. Using Table 1 as a guide, check the rest of the current
ranges by applying the a~ropriate current and verify-
ing that the reatig is within the allowable limits.
Table 1. Range Accumcy
263 Output
(AMPS)
1.90M0 A
19.0000 M
190.WO A
1.90000 PA
19.0000 ~A
190.000 @
1.9oooofl
*Includes Model 263 error.
Allowable Reading*
(M"C -28°C)
1.8933 to
1.9067
B.936 to 19.064
M9.69 to
190.31
1.8976
to
1.9024
28.986
to
19.014
E9.86 to
lW.14
1.8986 to
1.9014