Keithley 237

+
APPENDIXF
236/237
Performance
Verification
Table
F-3.
Model263
1-Source Characteristics
263 1-Source
Programmed
Characterized
1-Source
Entry
Range
Value
1-Source
Value
Value
Limits*
1
2J.LA
0.90000J.LA
lo.9J1A
=
0.9J.LA
±450pA
2
20J.LA
9.0000J.LA
I9J1A
=
9JlA±4.3nA
3
200J.LA
90.000J.LA
I9011A
-
90JlA±45nA
4 2mA
0.90000mA
Io.9mA
=
0.9mA ±430nA
5
20mA 9.0000mA
I9mA
=
9mA±5.4JlA
"The
characterized !-source values should
be
within
the listed limits. These limits
are
based
on
90-day
specifications of the Models 263
and
193A. A characterized value
that
does
not
fall
within
these limits indicates a calculation error,
or
that
the Model263
and/
or
Model 193A is
out
of
specification.
13.
As
performed
in
steps 8
and
9, measure the voltage
across
the
100k.Q
resistor
and
calculate
the
current.
Vtooldl
=
-------
V
Vtooldl
I9J1A
=
--
--------
J.1A
Rtooldl
I9J1A
is the characterized current for
the
20J.LA
range
of
the
Model263.
It
is
used
to check
the
10JlA
measure-
mentrangeoftheModel236/237.
Usingapencil,re-
cord
the
calculated value
of
I9J1A
in
Entry 2
of
TableF-3.
14.
Place
the
Model263
in
standby.
15.
In
the
test fixture, remove
the
100k.Q
resistor
and
in-
stall the
1k.Q
resistor (R-263-1k).
16.
On
the
Model193A, select
the
Ohms
function,
2kQ
range
and
disable
ZERO.
17. Repeat
step
3 to zero
the
Model193A.
18. Measure
and
record
the
value
of
the
1k.Q
resistor.
Rtldl
=
-------
kQ
19.
Set
the
Model193A
to
OCV
and
the
200mVrange,
and
disable
ZERO.
20.
To cancel
any
offset, zero
the
Model193A
by
short-
ing
its
input
(VOLTS
ID
to
LO)
and
enabling
ZERO.
+
21. Remove the
short
from
the
input
of the Model193A
and
set
the
Model 263 to source
90.000J.LA
on
the
200J.LA
range
and
enable OPERATE.
22.
Record
the
voltage measurement from
the
Model
193A
and
calculate
the
current.
Vtldl
=
-------
m
V
I9011A
=
Vtldl
Rtldl
=·-------
JlA
I90J1A
is
the
characterized current for the
200JlA range
of
the
Model263.
It
is
used
to check
the
100J.LA
meas-
urement
range
of
the
Model 236/237.
Using a pencil,
record
the
calculated value
of
I90J1A
in
Entry 3 of
TableF-3.
23.
Place
the
Model263
in
standby.
24. Set
the
Model193A to
the
2V
range.
25. Set
the
Model263 to source
0.90000mA
on
the 2mA
range,
and
enable OPERATE.
26. Record
the
voltage measurement from
the
Model
193A
and
calculate
the
current.
Vtldl
=
-------
V
lo.9mA
=
Vtoon
_
mA
Rtoon
·-------
F-5