Keithley 237

SECTION1
Getting
Started
Line Frequency
The instrument will operate
at
a line frequency of
50
or
60Hz.
If
the line frequency setting of
unit
is in question,
proceed to paragraph 2.2.6 to check and,
if
necessary,
change it.
1.9 CONNECTIONS
The
Source
Measure
Unit
is intended to
be
used
with
a
test fixture for OUT in order to maintain safety
and
opti-
mize performance. The operating examples in this sec-
tion use the Keithley
Model8006 test fixture which is de-
signed to be
used
with
the Source Measure
Unit.
How-
ever,
an
alternate test fixture can
be
used
as long as the
following safety criteria are followed:
•
The test fixture
must
be
completely enclosed to pre-
vent
human
access to live
circuitry.
+
•
The test fixture
must
use
a safety interlock such that all
power
connected to
it
will
be
interrupted when it is
opened.
•
The chassis of the test fixture
must
be
connected to a
safety earth
ground
to prevent shock hazards.
1.9.1
Source Measure Unit Connections
to Test Fixture
Source Measure
Unit
connections to the
Model8006
test
fixture are shown in Figure
1-16.
Notice that
all
three
triax
connectors of the Source Measure
Unit are con-
nected to the test fixture. These connections extend guard
and
remote sense to the test fixture. The cables used for
these connections are 3-slot triax cables.
The interlock feature of the Source Measure
Unit
is en-
abled
when
the interlock cable is connected to it. With
this
feature, the Source Measure
Unit
will
go into standby
whenever the lid of the test fixture is open
or
ajar.
Model
236/237/238
236-ILC-3
7078-
TAX
Interlock
Cables
Cable
Model 8006
Rear
Panel
WARNING:
Test fixture chassis must
be
connnected
to
a safety
earth
ground.
Figure
1-16.
SMU
Connections
to
Test
Fixture
1-20
+