Keithley 236 Service Manual

SECTION
1
Performance Verification
Connect
the test fixture
screw
to safety
earth
ground
using #18
AWG
wire
mmi
mum
before use.
Turn off all
power before
connecting
or discomtecting
wires
or
cables.
Also, keep in mmd that
GUARD
is
always
enabled.
Thus,
a lethal
voltage
on
OUTPUT
HI
is
also present
on the
two
GUARD
termi
nals
of the Model 236/237.
Instrument
Type
Required
Specifications
DMM
Same
as
Keithley
193A
(see
Table
1-1)
Source
dc Current
O.9nA,
9nA,
9OnA,
Same
as
Keithley
263
(see
Table
14)
O.9iiA;
±l8Oppm
9iA, 9OpA,
900pA,
9mA;
±l7Oppm
Measure
dc
Current
25Oppm
rdg ±500nA
1 .5.1
Equipment
Characterization
In
order
to
verify
the
1iA,
1OiA,
lOOj.tA
and
imA
source
and measure
ranges
of the Model
236/237,
the
O.9iA,
9jaA, 9OjaA,
O.9mA
and
9mA
outputs
of the Mode1263
are
characterized.
For
the
lOmA
source
and
measure
range, a
1O2 resistor
is characterized.
Perform
the following
steps
for characterization:
1. Connect
the
Model
263
source,
Model
193A DMM
and Model
8006
test
fixture
as
shown
in
Figure
1-1.
Install the
lOOk2
resistor
(in Table
14)
in the
AXIAL
KELVIN
CLIPS
test
socket
of the test
fixture.
2. Configure
the source
and
DMM
as
follows:
Model 263
—
Amps
function,
+O.90000pA
on
2i.tA
range,
GUARD
enabled
and
output
in standby.
Model
193A
Ohms
function
on
the
200k2
range.
3.
Zero
the Model
193A as
follows:
A.
At the
SENSE
1
(HI)
terminal
of
the test
socket
disconnect
the
jumper whose
other
end is con
nected to
BINDING
POST
2
on the
Signal
Panel.
B.
Connect
that
jamper
to
the
SENSE 2
(LO)
termi
nal of
the
the test
socket,
This shorts
the
Ohms
Sense
input of
the
Model
193A
at
the
test
socket.
c.
On the
Model
193A,
enable ZERO
to cancel
test
lead resistance.
D. Relocate
the
jumper
back to
the SENSE
1
termi
nal of
the test socket.
Make
sure
the connections
at
the Component
Test
Module
are
correct
as
shown
in
Figure
1-1.
4.
In
the space
provided
below,
use a
pencil
to
record
the
actual value
of
the
lOOk2 resistor
from
the
dis
play
of
the
Model
193A.
Riooico
=
__________________________
ki2
5.
Set
the Model
193A to
the DCV
ftmction
and the
200mV
range, and
disable
ZERO.
6.
To
cancel any
offset,
zero
the
Model
193A by
short
ing
its input
(VOLTS
HI to
LO)
and
enabling
ZERO.
7.
Remove
the
short
from
the input
of the
Model
193A
and place
the
Model
263
in
operate
to
source
+O.9OOOOiA
to
the
100kL2
resistor
8.
In
the
space
below,
use a pencil
to record
the
voltage
drop
across
the
resistor
from
the
display
of
the
Model
193A.
VOOk2
_________________________
mV
9.
Calculate
(to
5-1
/2
digits)
the current
through
the
lOOk2
resistor
as
follows:
VlOOk2
Io9=
T)
=___________
lMOOki2
Io.9
IS the characterized
current
for
the
2iA
range
of
the
Model 263.
lt is
used to
check
the
1.tA
measure
ment
range
ofthe
Model
236/237,
Using a
pencil, re
cord
the
calculated
value
of
Io9&
in
Entry
1
of
Table
1-3.
Table
1-2.
Specifications
For
Alternate
Equipment
1-3

Keithley 236 Specifications

General

Brand	Keithley
Model	236
Category	Measuring Instruments
Language	English