Keithley 153, Instruction Manual, Page: 9 / 51

MODEL 153
SECTION 2.
2-1. FRONT PANEL CONTROLS AND TERNINALS.
OPERATIO:-J
OPERATION
a.
METER Switch. The METER
Switch has
four positions. POWER
orr shuts
off the in­
s
t
r
u
men t ; this also
short
circuits the meter, allowing accurate mechanical
zero adjust­
m e nt . METER + and
H
E T
ER
- determine meter polarity . CENTER ZERO
sets the
instrument
for center zero
operation (lower meter scales).
h. FUNCTION Switch. The FUNCTION Switch has three positions,
t\o.'O for voltage inputs
a
n
d one for
current i
n
pu
t s .
In
the
VOLTS INPUT R-2M
position, input
resistance
is ap­
proximately 2
megohms.
In
the
VOLTS R
-
OPE
N
position, input
resistance
is
at
the
maxi­
mum for
the
range being
used.
(See
Table
1.)
In
the
MIPS posi
tion, the Hodel
153 func­
t i o ns as an ammeter.
c.
RANGE
Switch. The
RANGE Sw
i t c
h
selects the full-scale instrument
sensitivity for
o
n
e of 17 voltage and 21 c
u
r r
ent
ranges. The
10
or 3 of
the
top meter scale corresponds
to full-scale deflection
for
the
range
selected with the RANGE Switch.
d.
ZERO
Control. The
ZE
R
O
Control allows precise meter
zeroing.
Its
r
a
n
g
e
is
about
20 microvolts, so it
i
s
most effective on the microvolt
ranges.
Since
the 3-volt and
higher ranges use a 1000:1 divider, the Control 1s also somewhat effective
on
the 3-volt
range.
It
has much less effect on other ranges.
e. INPUT Receptacle. The INPUT Receptacle is
a
Teflon-insulated
T
r
i
a
xi a l
type con­
nector. Its center terminal is
t
he circuit high; the inner shield
is
circuit
low (ci
r
­
cuit ground); the outer shield is chassis ground.
2-2. REAR PANEL
CONTROLS
AND
TERMINALS.
a. DC
OUTPUT ADJ
Control. This
Control
sets the amplitude of
the
output voltage.
Both the output voltage and res1stance vary W1tn the control setting. Voltage span is
from
0
to
1.05
volts; output resistance varies to
7.5 kilohms
maximum.
b. Output
Binding
Posts. Three posts
are
used for the I-volt recorder output.
G is
f · -:'r
case ground; LO is circuit ground;
HI is
the output connection.
The
furnished short­
; ;",: link
is
for connecting the
LO
Post
to
the
G
Post.
c. 117-234 Switch.
The screwdriver-operated slide switch sets the Model
153
for 117
or
234-volt ac power lines.
d. FUSE. For 105-125 volt operation, use a
1/2
ampere, 3
AG
Slow B
l
o
w
fuse. For
210-250 volt operation, use
a
1/4
ampere,
3 AG
Slow Blow fuse.
e.
Power Cord. The 3-wire power cord with the
NEMA
approved 3-prong plug provides
a
gr
o u
n
d
connection
for the cabinet.
An
adapter for operation from 2-terminal outputs
is
provided.
NOTE
The
Model
153
INPUT
Receptacle
is a
Triaxial
connector. Any attempt
to
con­
nect
bnc-type connectors to it may damage both.
3