Keithley 237

SECTION2
Operation
Model
236/2371238
Model8006
WARNING
:
To
avoid
electric
shock,
test fixture chassis must
be
connected
to
a safety
earth
ground.
A. Source Measure Unit
Connections
to
Test Fixture
+
OUT
.___8006
_ ___.
==¥
Test Fixture
2361237/238
B.
Connections Schematic
(Guard extended
to
DUT)
Figure
2-7.
Remote
Sense
Connections
Using
Model8006
Test
Fixture
2.3.4
Custom Test Fixture
The
Model
8006
test
fixture is
one
of
the
most
versatile
test fixtures available.
The
connection
jumper
panel
makes
it
simple
to
connect
one
or
more
Source
Measure
Units
to
one
of a variety
of
OUT
test
sockets.
In
a situation
where
numerous
devices
that
are
similar
need
to
be
tested (such as
component
evaluation),
it
may
become
necessary to
build
a
dedicated
test fixture.
A
simple dedicated test fixture is
shown
in
Figure
2-8.
To
keep
the
concepts clear, single Source
Measure
Unit
con-
nections
to
a single
OUT
socket
are
shown.
Figure
2-8
is
intended
to
illustrate
the
basic techniques
that
should
be
applied
when
building
a test fixture.
In
reality,
the
test
fixture
may
need
multiple
OUT
sockets (wired
in
parallel
to
each other), additional
input
triax connectors to ac-
commodate
two
or
more
Source
Measure
Units,
multi
pin
OUT
sockets,
and
perhaps
input
banana
plugs
to
bring
in
additional
power
for
packaged
devices.
The following requirements, recommendations
and
guidelines
are
provided
in
order
to
build
a quality
test
fixture
that
is safe
to
use.
2-12
+
Test
Fixture
Chassis
1.
The
chassis
of
the
test fixture
should
be
metal
so
that
it
can
function
as
a shield for
the
OUT
mounted
in-
side.
The
chassis
of
the
test
fixture
will
be
connected
to
Source
Measure
Unit
chassis via
the
triax cables.
2.
The
test
box
must
have
a
lid
that
closes
to
prevent
contact
with
live circuitry inside.
WARNING
Safe
operation
requires
that
a
safety
inter-
lock
switch
be
used
to
interrupt
all
power
sources
when
the
test
fixture
lid
is
open
or
ajar
(see Interlock).
3.
The
test fixture chassis
must
have
a screw terminal
that
is
used
exclusively for connection
to
a safety
earth
ground.
WARNING
To
provide
protection
from
shock
hazards,
the
test
fixture
chassis
must
be
properly
con-
nected
to
safety
earth
ground.
A
grounding
wire
(18
A
WG
or
larger)
must
be
attached
se-
curely
to
the
test
fixture
at
a
screw
terminal