Keithley 486 Instruction Manual page 164

SECTION 7
Maintenance
9.
10.
11.
12.
13.
14.
and repeat the basic procedure in steps 5 through 7
using the following calibration command:
L3,19E-9X
Set the Model 486/487 to the 2OOnA range, set the
Model 263 to source 19O.OOOnA on the 2OOnA range,
and repeat the basic procedure in steps 5 t.hro~.@ 7
using the following calibration command:
L3,19OE+X
Set the Model 486/487 to the 2@ range, set the
Model 263 to source 1.900@&4 on the 2!.tA range,
and repeat the basic procedure in steps 5 through 7
using the following calibration command:
L3,1.9E-6X
Set the Model 486/487 to the 20@ range, set the
Model 263 to source 19.OOCQu-I on the 2OpA range,
and repeat the basic procedure in steps 5 through 7
using the following calibration command:
L3,19E-6X
Set the Model 486/487 to the 200@ range, set the
Model 263 to sauce 19O.ooO@ on the 2OOM range,
and repeat the basic procedure in steps 5 through 7
using the following calibration command:
L3,19OE-6X
Set the Model 486/487 to the 2mA range, set the
Model 263 to source 1.9OOOOm4 on the 2mA range,
and repeat the basic procedure in steps 5 through 7
using the following calibration command:
L3,1.9E-3X
Place the Model 263 in standby.
NOTE
For the Model 486, place the CAL LOCK
switchin the "out" position to disable calibra-
tion. Do the same to the Model 487 if you are
not going to calibrate the voltage source.
Voltage Source Calibration (Model 487)
In general, the voltage source of the Model 487 is cali-
brated by adjusting the output until OV and full scale are
measured by a DMh4 and then sending the calibration
command.
NOTE
After a calibration command is sent over the
bus, front panel con~ols are locked out. To
perform a front panel operation make sure
you fist press the LOCAL key.
Perform the following steps to calibrate the V-Source of
the Model 487:
1.
2.
3.
4.
5.
6.
7.
8.
9.
WARNING
The following procedure uses hazardous
voltages that could cause severe injury or
death. Exercise extreme caution when per-
forming this procedure.
Zero the 2OOmV range of the Model 197 DMM and
select autorange.
Make sure the V-Source (voltage source) of the
Model 487 is in standby, then connect the Model 197
DMM to it as shown in Figure 7-3.
While in standby, set the V-Source to the 50V range
by sending the following command over the bus:
v,ox
Place the v-source in operate.
Send the following command over the bus to pre-
pare the 50V range for calibration:
L6X
Adjust the V-Source output of the Model 487 to
measure (as close as possible) OO.OOOmV on the
Model 197.
Send the following comman d over the bus to cali-
brate OV on the 5OV range:
LAX
Adjust the V-Source output of the Model 487 to
measure +5O.OOOV on the Model 197.
NOTE
If the output cannot be adjusted bigb enough
to measure 5O.oOOV on the Model 197, set the
V-Source to its madmum output setting
(50.5OOV displayed on the Model 487).
Send the following command to calibrate the 50V
range at full scale:
7-7