Keithley 236 Service Manual

SECTION
2
Calibration
30.
Send
the following
command
to
source +0V
on the
when the
Model
236/237
is turned
off. Permanent
1 100V range:
calibration
can
stillbe
done by
setting
the calibration
switch
to
the “in“ position,
and
sending
COX and
v1x
! Enable
1100V range
C59X over
the
bus in
that order.
C26X
!
Source
+0000.0V
After
sending
the
C59X
command,
the
Model
31. Send
the
measured
voltage
reading
(VMSR)
over the
236/237
Wffl return
to
normal
operation.
bus
with
the C27
command
as follows:
39.
Place
the Model
236/237
in standby.
C27,VMSRX
! Calibrate offset; +1100V
40. Send
the following
command
over
the
bus to
disable
source
and measure
range
the
1100V range:
32.
Send
the
following
command
to source
+1000V:
VOX
! Disable
1100V
range
C28X
! Source
+1000.0V
2.6.3
lOOmA
Range
Calibration
33, Send the
measured
voltage
reading
(VMSR)
over the
To
calibrate
the lOOmA
range,
connect the
circuit shown
bus with the C29
command
as follows:
in Figure
24. The
102 resistor
installed
in the
test
fixture
is one that
was previously
characterized
in the
equip
C29,VMSRX
! Calibrate
gain; +1100V
source
ment characterization
procedure.
Note
that the accuracy
and
measure
range
of this calibration
is highly
dependent
on the
accuracy
of
the
characterized
value
of
the 102
resistor.
Enter the
34. Send
the following command
to source
-0V
on
the
characterized
value
of the 1OQ
resistor
(see
paragraph
1100V
range:
2.6.1,
step
43)
in the space
below:
C3OX
! Source —0000.0V
R 10
=
_________________
35,
Send the measured
voltage
reading
(VMSR)
over
the
bus
with
the C31
command as
follows:
Perform the
following
steps
to
calibrate
the
lO0mA
source
and
measure range:
C31,VMSRX
!
Calibrate
offset;
—1
100V source
1.
Temporarily
disconnect
the
output
of
the Model
and measure
range
236/237
from
the test
fixture.
2. Set
the
Model
193A DMM
to
the
2VDC
range
and
36. Send
the following command
to source
—1000V:
then
enable ZERO
to
cancel
any
offset.
3.
Re-connect
the
output of
the Model
236/237
to the
C32X
!
Source
—1000.0V
test
fixture.
4, Place the
Model 236/237
in
operate.
The
calibration
37,
Send
the measured
voltage
reading
(VMSR)
over the
mode
cannot
be entered
with
the
Model
236/237
in
bus with
the
C33
command as follows:
standby.
5,
Over
the IEEE-488
bus,
send the
following
command
C33,VMsRX
! Calibrate
gain;
—1100V source
to enter
the calibration
mode:
and
measure
range
c0x
!
Enter
calibration
mode
38.
Send
the following
command
over
the bus:
Note:
All other
calibration
commands
(Cl
through
C59)
will be
ignored
unless the
CO
command
is
first
Note: Check
that
the
CAL
LOCK
switch
is in
the de
sent
over
the
bus.
sired position;
“in“
for permanent
calibration,
or
“out“
for temporary
calibration.
6.
Send
the
following
command
to
source
+OmA
on the
100mA
range:
C59X
! Exit calibration
and
store
cal
constants.
C34X
!
Source
+000.00mA
If the
switch
is in the
“out“
position,
the
message
7.
From the
display of
the Model
193A
DMM,
record
“TEMPORARY
CAL“ willbe
briefly
displayed
to in-
the voltage
drop
across
the
102
resistor
(Vio)
in the
dicate
that newly
entered
cal constants
will be
lost
space
below.
2-9

Keithley 236 Specifications

General

Brand	Keithley
Model	236
Category	Measuring Instruments
Language	English