Keithley 237

APPENDIXF
236/237
Performance
Verification
lo.9mA
is
the
characterized current for
the
2mA range
of
the
Model263.
It
is
used
to check
the
lmA
meas-
urementrangeoftheModel236/237.
Usingapencil,
record the calculated value
of
lo.9mA
in
Entry 4
of
TableF-3.
27.
Place
the
Model263
in
standby.
28.
In
the
test fixture, remove
the
lk!l
resistor
and
install
the
lOOn
resistor (R-249-100).
29.
On
the
Model193A, select
the
Ohms
function,
2000
range
and
disable
ZERO.
30.
Repeat step 3 to zero the Model193A.
31.
Measure
and
record
the
value of the
1000
resistor.
Rtoon
=
-------
n
32. Set the Model193A to DCV
and
the
2V
range,
and
disable
ZERO.
33.
To cancel
any
offset, zero
the
Model193A
by
short-
ing
its
input
(VOLTS
ill
to
LO)
and
enabling
ZERO.
34.
Remove
the
short
from
the
input
of
the
Model193A
and
set
the
Model263
to source 9.0000mA
on
the
20mA
range
and
enable
OPERATE.
35.
Record
the
voltage measurement from
the
Model
193A
and
calculate
the
current.
Vtoon
=
-------
V
Vtoon
19mA=
--
=
rnA
Rtoon
·-------
19mA
is the characterized current for
the
20mA
range
of the Model263.1t is
used
to check
the
lOrnA meas-
urement
range
of
the
Model 236/237.
Using
a pencil,
record
the
calculated value
of
19mA
in
Entry 5 of
TableF-3.
36.
Place
the
Model263
in
standby.
37.
In
the
test fixture, remove
the
lOOn
resistor
and
in-
stall
the
10n
resistor (R-185-10).
38.
On
the
Model193A DMM, disable
ZERO
and
select
the
200m V
DC range.
39. While
in
standby,
setthe
Model263 to
+9.0000mA
on
the
20mA
range.
40.
Zero the Model193A
by
shorting its
input
(VOLTS
ill
to LO)
and
enabling
ZERO.
F-6
+
+
41. Remove
the
short from the
input
of
the
Model193A
and
place
the
Model263
in
operate.
42. Record
the
voltage measurement from the Model
193A
and
then
place the Model263
in
standby.
Vton=
_______
mV
43.
Calculate the actual resistance
of
the
10n
resistor as
follows:
Rton=
Vwn
19mA
=
_______
n
where;
19mA
is obtained from Table
F-3.
Rton
is
used
to verify
the
lOOmA
source
and
measure
range
of
the
Model236/237.
F.5.2
Common Mode Verification
Set
up
the
equipment
as
shown
in
Figure F-2
and
per-
form
the
following steps for common
mode
verification.
1.
While
in
standby,
program
the
Model236
/237
as fol-
lows;
f TIME
at
LINECYCLE
PERIOD, source
at
+
l.OOOO!JA,
and
compliance
at
1
Von
the
1.1
V
range.
2
Place the
Model236/237
in
OPERATE
and, using a
·pencil,
record
the
voltage measurement
in
the space
provided
below.
V+tJ.LA
=
-------
V
3. From the keypad, change the source value to
-l.OOOOIJA
and
record
that
measurement.
V-tJ.LA
=
-------
V
4.
Subtract
the
two
voltage measurements from each
other. Verify
that
the
absolute value of the result is
<150J.!V.