INSTRUCTION MANUAL
COPYRIGHT
1977,
Model
Picoammeter
414s
KEITHLEY INSTRUMENTS, INC.
PRINTED MAY 1978, CLEVELAND,
OHIO,
U.
S.
A.
CONTENTS MODEL
CONTENTS
1.
2.
3.
4.
5.
6.
414s
7.
ii
0675
MODEL
414s
ILLUSTRATIONS
ILLUSTRATIONS
Fig.
No.
Title
Page
3
3
5
6
11
14
15
25
0675
25
iii
SPECIFICATIONS
SPECIFICATIONS
MODEL
414s
RANGE:
ACCURACY:
ZERO DRIFT:
10-lo ampere full scale to ampere in seventeen
lx
and
3x
ranges, positive or negative currents.
&2%
j=4%
of full scale on
0.05%
per
of full scale on to ampere ranges:
3
x
10-9
to
10-10
ampere ranges.
Less than
“C
on any range after a 10-minute warm-up and
0.5%
of full scale per week plus
with source voltages greater than 1 volt.
INPUT VOLTAGE DROP:
meter deflection
EFFECTIVE INPUT RESISTANCE:
ampere range, increasing to less than
Less than 1 millivolt for full-scale
on
any range when properly zeroed.
Less than
0.1
lo7
ohms on
ohm on
ampere range,
RISE TIME, MAXIMUM:
Range,
atnoere
10.10
10.9
10.6
10-7
10
-6
and
Seconds, from
above
With
Across
less
10%
up
0.75
0.15
0.13
0.09
0.05
than
to
to
Innut
90%.
500
pF
0.001
MAXIMUM INPUT OVERLOAD:
Transient:
(or other 10
Continuous:
1000 volts for up to 3 seconds using a Keithley
rnA
limited) High Voltage Supply.
600
volts on
10-lo
to 10-6 ampere ranges, de-
creasing to 12 volts on the ampere range.
CURRENT SUPPRESSION: (Model
414s
only):
Up to
times full scale.
Suppression Range:
ampere to ampere
decade steps, precision 10-turn potentiometer for inter-
polation between steps. Selectable polarity.
CONNECTORS:
Input: Teflon-insulated UHF type. Output:
Amphenol8OPC2F.
RECORDER OUTPUT:
Output:
fl
volt or 1 milliampere for full-scale meter
deflection. Output polarity is opposite input polarity.
Noise:
414s:
414A: Less than
Less than
POWER:
5
watts.
105-125
or
DIMENSIONS, WEIGHT:
0.3%
1%
of
of full scale peak-to-peak.
full scale peak-to-peak.
210-250 volts (switch selected),
5%“
high x 8%” wide
x
50-60
10”
deep;
net weight, 8 pounds.
ACCESSORIES SUPPLIED:
Mating input and output con-
nectors.
lom2
10’lo
100
in
7
Hz,
iv
0675
1
c
MODEL
414s
GENERAL
DESCRIPTION
SECTION
1-1.
GENERAL.
a.
The Keithley Model
state
pcioammeter which measures currents over
ranges from to
is
52%
of full
24%
and
ranges.
tors
stage,
stage. Negative feedback
accuracy.
1-
Picoammeter
of full
b. The Picoammeter employs matched MOS FET transis-
in
the input followed by a differential amplifier
a
2.
FEATURES.
a. The
ammeter.
requiring rezeroing. Zero drift with
0.5%
of full scale per week. Temperature drift
equally
less
small
than
scale
scale
transistor driver and a transistor output
time
and temperature stability of the
is
unmatched by any other inexpensive pico-
The Model
-
a
0.5%
change of 10°C affects the reading
of full scale
414s
is
a
completely solid-
10-lo
ampere full scale. Accuracy
on
the to
on the
is
414s
will
3
used for stability and
on
10-8
x
10-9
operate for days without
the most sensitive
1.
17
ampere ranges
to
10-10
ampere
time
is
less
4145
is
GENERAL DESCRIPTION
than
b. A unique circuit provides complete overload protection for Model
standing features
meter
will
volts without damage, and overload recovery
instantaneous
c.
the Picoammeter.
its
most sensitive range. For maximum stability, how-
ever, about 10 minutes warm-up
d. One volt or
tion
ers.
Keithley
recorders are used, the output voltage can be conveniently divided by a shunt resistor and adjusted for
full scale with the rear panel Calibration potentio-
meter.
withstand transient overloads up to
Fast warm-up
on
all
The 1 milliampere recorder output
370
414s
of
the
.
is
an inherent characteristic of
It
can
1
ranges
Recorder directly.
milliampere
is
provided to drive chart record-
without compromising the out-
MOS
FET input.
be used
time
almost
at
When potentiometric
The
Picoam-
1000
is
almost
immediately on
should be allowed.
full-scale deflec-
will
drive the
P
P
?-
0272
1
OPERATION
Con
t
r
ol
TABLE
Front Panel Controls
2.
Functional Description
MODEL
Par.
414s
RANGE
Switch
METER
Switch
ZERO
ADJ.
Control
Pilot Light
SUPPRESSION,
SUPPRESSION, FINE and Polarity
Switch
t
r
o
1
Con
INPUT Receptacle
OUTPUT Receptacle
MAX
AMPERES Switch
Connects input to source. Receptacle
UHF Connector.
Connects output to monitoring device.
Selects full-scale current range instrument
measure.
Turns instrument
instrument zero.
Zeroes
Glows to indicate instrument
Selects suppression current magnitude and turns suppression current off.
Concentric switches: one determines polarity of suppression current, the other (FINE) varies the suppression
from zero to maximum
meter
Rear
Functional Description
on;
selects
on
any range.
set
TABLE
3.
Panel Controls
~~
meter
is
by the
is
polarity; checks
on.
MAX
AMPERES
a
Teflon insulated
is
to
Switch.
I
2-2
2-2
2-2
---
2-2
2-4
1
Par.
2-1
2-5
1
MA
-
1
MA
CAL
117-234
Fuse
I
V
Switch
Control
V
Switch
1
Selects output of instrument:
Adjusts output from 0.95 to 1.05
Sets instrument for 117 or 234 volt ac power line.
3AG
Slow-Blow.
117
volt - .125
milliampere or 1 volt.
mA.
A;
234 volt - .062
A.
2-5
2-5
2-2
2-6
2
0272
6
MODEL
414s
GENERAL DESCRIPTION
RANGE
-WITCH
S
103
3
r
INPUT
5102
I-
POWER ON METER ZERO
INDICATOR
DS201
I
SWITCH CONTROL POLARITY
Slol R131 CONTROL CONTROL SWITCH S102
FIGURE
1.
I
ADJ
S
Front
I
SUPPRESSION SUPPRESSION
104
Panel Controls.
IMA
CA1
FINE
R108
IMA-IY
I
MAX
/
AMPERES
I-
OUTPUT
1MA-lV
TWITCH
S
105
AUTPUT
5103
1
17
-23
f
-ELECTOR
4V
s201
w
I
FIGURE
0272
2.
Rear
Panel
Controls.
3
OPERATION
MODEL
414s
PICOAMPETER
SECTION
2-1.
INPUT
when using the Picoammeter on
a. The INPUT Receptacle of the Model
lon-insulated
the high impedance terminal, and the outer shield
case ground.
b. Carefully shield the input connection and the cur-
rent source being measured, since power line frequencies
well
are
ranges. Unless shielding
definite meter disturbances.
c. Use high resistance,
as polyethylene, polystyrene or Teflon
tion. The insulation resistance of test leads and fixtures should be several orders of magnitude higher than
the source resistance. Excessive leakage
accuracy. Any coaxial cable used should be a lownoise type which employs a graphite coating between the
dielectric and the surrounding shield braid.
d. Any change in the capacitance of the measuring
circuit to ground
ing, especially
measuring setup as rigid as possible, and tie down con-
necting cables to prevent their movement. If a continuous vibration
as a sinusoidal signal and other precautions may be
necessary to isolate the instrument and the connecting
cable from the vibration.
CONNECTIONS. Use
UHF
connector. The center terminal
within the pass band of the Picoammeter on all
will
on
is
cause disturbances in the read-
the more sensitive ranges. Make the
present,
the following precautions
the more sensitive ranges. etc. positions, use the upper meter scale.
414s
is
is
thorough, pickup may cause
low-loss
it
NOTE
materials - such
-
for insula-
will
may appear at the output
2.
a Tef-
is
is
reduce
OPERATION
1.
When the
scale current range
ting.
2.
When the
etc. positions, use the lower meter scale.
scale current range is equal to the
setting
2-3. MEASUREMENT CONSIDERATIONS,
a. The Picoammeter employs the fast method of cur-
rent measurement
the amplifier input and output in the feedback loop.
This method largely neutralizes the effect of input
capacity and greatly increases the response speed.
Also,
of one millivolt on any range.
b. Rise time varies with the current range and the
input capacity (see specifications, Table
time,
across the input; however,
Picoammeter nearer the current source than to the data
reading instrument. Transmitting the input signal
through long cables
of capacitance
noise.
c. The internal resistance of the unknown source
should not be less than the reciprocal of the current
range being used, otherwise the zero stability
affected. The instrument
ever, but the stability
amount given by equation
Stability = 0.5%/week x (Rs + Rf)/Rs
.
the input voltage drop
though,
RANGE
Switch
is
RANGE
Switch is set to 3,
-
the measuring resistor
is
not affected with up to
-
-
with greater than
will
increase response time and meter
will
is
set to
equal to the
is
reduced to a maximum
it
is
better to place the
will
still
be degraded by the
1.
10,
1,
0.1,
RAEiGE
RANGE
be operable, how-
Full
SiJitch set-
0.3,
Full
Switch
is
between
1).
The rise
500
picofarads
500
picofarads
will
Equation
0.03,
be
1.
.
where
Rf
is
Keep the shield cap on the INPUT Receptacle
when the Picoammeter
2-2.
OPERATING PROCEDURES.
a. Check the fuse and the 117-234
proper line voltage.
b. Connect the power cord to the power source.
is
not in a circuit.
V
Switch for the
For example, if the source to be measured has a resistance of
back resistor
gain of the Picoammeter
stability of .5%/week
the offset due to temperature
.5%/'C.
RANGE
Set the
c.
SAtch
read zero. Zero the meter with the
After a few moments increase the current sensitivity b
advancing the
ampere range. Continue zeroing with the
trol. The instrument
the instrument to warm up for at least
and turn the METER Switch to the polarity of the input
signal,
Switch until the greatest on scale deflection is achieved,
to
(+).
d. If long term measurements are to be made, allow
e. Attach the current source to the INPUT Receptacle volts without damage.
+
or
-.
Switch to
Within seconds the meter needle should
RANGE
Switch in decade steps to the
is
Increase sensitivity with the
lom2
ampere, the
ZERO
now ready to use.
10
METER
ADJ.
Control.
10-
ZERO ADJ
minutes. meter can withstand overloads of up to
Con-
RANGE
have the source resistance at least equal to the feedback resistor.
15
d. Overload Protection.
complete overload protection for the Model 414s without compromising the features of the MOS
Recovery
1.
for 3 seconds and continuous overloads of up to
2.
is
a function of rated power dissapation in the resistor.
the feedback resistance in ohms;
R,
is
the source resistance in ohms.
105
ohms and the current
will
This
is
is
instantaneous for most overloads.
At
the ampere range and below the Picoam-
Above amperes, the max. continuous overload
4
be
106
ohms. his means that the
is
106/10T
will
be
.5%
the reason that
will
A
unique circuit provides
is
lom6
then the feed-
=
10.
X
be
it
Then the zero
10 = 5%/week, and
.05%
X
is
lo*=
advantageous to
E'ET
input.
1000
volts
600
02
-
..4
72
MODEL
414s
OPERATION
f-
Allowable Overloads
Range Voltage Overload Current Overload
10-5
A
10-4
A
10-3
A
A
3. For maximum protection, use
240A Voltage Supply, or some other 10 milliampere FIGURE 3. Divider Circuits Across Picoammeter Output
current limited supply, in combination with the for Driving
Picoammeter.
2-4.
RECORDER
a.
For recording with the Model 414S, use the Keithley Model 370 Recorder for
and performance. The Model 370
10 chart speeds and
put cable has
the OUTPUT Connector
interface problems often encountered between a measur-
ing instrument and
when
set
preamplifier
r
b. Other recorders, oscilloscopes and
struments can be used with the Model 414s. The Picoammeter has two outputs,
to amplify signals for recorders, oscilloscopes and
similar
recorder amplifiers to the OUTPUT Receptacle. Pin
1
the
is
range. Internal resistance
Noise
METER Switch does not reverse the output polarity.
Output polarity
instruments to the OUTPUT Receptacle. Pin
the high terminal. Set the
The output
scale
apply
adjust the
full scale, Check the recorder and
repeat adjustment if necessary. The METER Switch does
not
rsite
across the Picoammeter OUTPUT Receptacle. See Figure
3. Set the OUTPUT Switch to
sc"
Control to
flections. Operation
instruments. These can be used
c. 1-Volt Output. Connect oscilloscopes and pen
is
the high terminal and pin
1
mA
now
21
is
d. 1-Milliampere Output. Connect 1-milliampere
meter
a
known full scale signal to the Picoammeter and
reverse
input polarity.
e.
For servo rebalance recorders, use a divider
OUTPUTS.
a
connector which
to the 1 mA
is
needed. No special wiring
-
1
V
Switch to
volt for full scale meter deflection
less
than
is
is
approximately 1 milliampere for full-
deflection
1
mA
CAL
the output polarity which
trim
the output for full-scale recorder de-
TABLE
4.
on
Ranges Above Ampere.
Max. Continuous Max. Continuous
300
V
120
v
30
V
12
v
a
Keithley Model
ease,
economy, versatility
is
1%
linearity. The Model 370's in-
on
the Picoammeter; this avoids
a
recorder. The Picoammeter output,
position,
a pen recorder with
mates
directly with
will
drive the 370;
similar
51
volt and
1
V.
is
1%
peak-to-peak of full scale. The
always opposite input polarity.
1
mA
on
any range. For
Control until the recorder reads
1
is
the
same
21
milliampere,
on
no. 2 is
The Picoammeter output
approximately 1 kilohm.
-
ground. Set
1
V
Switch to
exact
meter
zero and
is
always oppo-
mA.
Use
the
as
for current outputs.
1mA
4mA
10
mA
40
mA
is
required.
all
ranges.
no.
1
mA
no
in-
no.
on
any
1
is
1
mA.
output,
CAL
1
OUTPUT
5103
RECORDER
OUTPUT
L
50
and 100-Millivolt Recorders.
2-5.,
234-VOLT OPERATION. The instrument
for use with
ordered. To convert the Picoammeter for 234-volt
sources, use
on
the back panel to the 234-volt position. Change'
the fuse from 0.125 ampere to ,062 ampere.
adjustment
volt operation, reverse the procedures.
2-6.
SUPPRESSION
provides up to 100 times current suppression over a
range of
ground currents, variations as
signal can be displayed full scale. Currents of either
polarity may be suppressed.
a. Suppression
opposite polarity to the input current at the input of
the Picoammeter. This suppression current
from
well
with resistors.
b.
Use
1.
-,
as
2. Set the SUPPRESSION,
same
the 10-turn FINE Control for
meter.
one decade. Adjust the FINE Control for
ing. This
tain
of the
meter.
fluctuations
current.
c.
When using
resistor used in the suppression circuit
tenth the value
this mode the zero drift and temperature drift
approximately ten
discussion
a
117-volt power source unless otherwise
a
screwdriver to change the slide switch
is
necessary. To switch from 234 to
loe3
CURRENT
to
lom9
OPERATION. The Model 414s
ampere. By suppressing back-
small
is
achieved by applying a current of
regulated 212 volt supplies in conjunction
the suppression circuit
Set the SUPPRESSION, Polarity Control to
necessary.
sensitivity
Increase the sensitivity of the
100
times
RANGE
In this mode the Model 414s
in
as
the
RANGE
is
ten
times
suppression, increase the sensitivity
Switch one more decade and zero the
of
1%
100
of
the current measuring resistor. In
times
paragraph 2-3c for explanation).
current suppression. To ob-
of full scale of the Suppression
times
full scale suppression the
greater than normal. (See the
as
MAX
AMPERES Switch to the
Switch setting. Adjust
a
zero reading
is
shipped
No
as
1%
in a larger
is
follows:
RANGE
a
zero read-
is
able to detec*
will
be
obtained
on
other
117-
+
or
the
Switch
one-
will
be
I
I
0272
5
CIRCUIT
DESCRIPTION
MODEL
414s
SECTION
3-1.
GENERAL.
amplifier with
3 volts. By using the front panel controls, shunt
sistors
of
223943 for circuit designations.)
3-2.
effect input transistors followed by
transistor stage,
sistor output stage. Figure 4 shows the simplified
circuit for the Picoammeter.
are
17
current ranges. (Refer to schematic diagram
AMMETER
a.
The amplifier has matched insulated-gate field-
The
Keithley Model 414s
a
full scale sensitivity of either 1 or
selected to make measurements over a total
OPERATION.
a
a
transistor amplifier and a tran-
Rs
3.
is
a
linear dc
differential
CIRCUIT DESCRIPTION
3-3.
re-
AMMETER
a.
Two
sistors,
put. Resistors R125 and R126 and circuit designation
21850B (see schematic) protect the gate of transistor
QlOl,
the active field-effect transistor, from over-
loads. The gate of Q102
ground.
b. Turning the
places
the instrument.
and Q104, drives an amplifier stage, transistor
which in turn drives the output
sistor 4106.
Control, R128 varies the source voltage of transistor
QlOl
Control, R131, varies the drain voltage of transistor
QlOl
current through transistors
the source bias,
a
c.
A
Two
d.
with respect to transistor 4102. The
with respect to transistor 4102.
e.
The
CIRCUIT.
balanced insulated-gate field-effect tran-
QlOl
and 4102,
short from the input to the output and zeroes
differential amplifier stage, transistors Q103
zero controls
DC
METER
Bal
Potentiometer,
are
used for the amplifier in-
is
returned to amplifier
Switch to
are
ZERO
CK
position
emitter
used. The Coarse Zero
R127,
QlOl
and 4102 by varying
follower, tran-
ZERO
sets
the drain
.
QlOS,
ADJ
FIGURE
b.
ein,
flows through the measuring resistor,
But the output voltage,
voltage
Therefore, from equations 2 and
From whence,
where
Thus, the input voltage drop
tion,
put resistance
Simplified Diagram for
4.
If
it
is
is
negligible, then
eo
=
times
eo
A
ein
ein/iin
1/A,
assumed that the input voltage drop,
-iin
R,.
the amplifier gain.
-A
ein. Equation 3.
=
iin
R,.
is
the effective input resistance.
of
the output voltage, and the effective in-
is
1/A
all
eo,
of the measuring resistor.
Ammeter
the input current,
is
also equal to the input
3
we
is
kept
Circuit.
R,
,
and
Equation 2.
get
Equation 4.
Equation
at
a
small
iin,
5.
frac-
f. The voltage drop across R123 plus R124, or R124
alone, determines the full scale sensitivity of the
amplifier
and 3 x
10-10
put causes
R123 and R124. The
volt output. Resistors R138 and R139
current.
g. The full scale current sensitivity
by the range resistors R109 through R122 in combination
with resistors R123 and R124. The current measuring
resistor
figuration increases the response speed by minimizing
the effects of input capacity.
input voltage drop to
h. The
milliampere flowing through resistor R143.
milliampere output mode an external load
for R143. Potentiometer R141 varies the current to the
external load.
3-4. POWER SUPPLIES. The Model 414s has positive and
negative supplies, which provide power to the amplifier and output.
a.
secondary of transformer T201
D201 and D203 and filtered by capacitor C201 to provide
+25 volts for the output. Zener diode, D205,
to provide
b. -25 and -12 volt supply. This supply uses diodes
D202 and D204, capacitor C202 and Zener D206 to perform the
-
either 3 volts from throu h 3
lom9
ranges.
a
and 3 x
Applying
1
milliampere current to flow through
1O-lo
meter
or 1 volt on
a
full
scale
signal to the in-
is
connected across the 3-
lO-Q,
set
is
is
connected in the feedback loop. This con-
It
less
than 1 millivolt.
1
volt recorder output
also reduces the
is
derived from
is
+25 and +12 volt supply. The power supplied from
a
regulated
same
functions
+11
is
rectified by diodes
volts for the amplifier.
as
the positive supply.
x
the
meter
determined
1
In the
substituted
is
used
and
1
c
?
6
0272
MODEL
414s
CIRCUIT
DESCRIPTION
6
3-5. SUPPRESSION
from two well regulated supplies in conjunction with
decade values of resistors and a ten-turn potentio-
meter.
ious resistors between the input of the
power supply. The magnitude of the suppression current
FINE Potentiometer, R108. Suppression current polarity
is
is
r
Suppression
is
determined by the setting of the SUPPRESSION,
determined by which power supply the potentiometer
connected to.
a.
+12 volt Supply.
1.
The secondary of the line transformer, T201,
is
rectified by diodes D201 and D203 and filtered by
C201 and applied to the collector of the
transistor, Q201. Resistor R202 and the zener diode,
D205, form
current. The positive supply does not use
directly for
volt supply
2. The base of Q206, connected
differential amplifier,
base of the other transistor, Q207,
the junction of two equal resistors, R211 and R212,
which
are
supplies. If the feedback to the
sistor
sistor 4207 must be approximately zero volts to maintain proper operating conditions. For this to be
so,
magnitude of the negative supply (12 volts).
of 4204, one-half of the differential pair formed
with Q205. The base of 4205
ference voltage
R207 and R208 connected between +12 and ground.
is
the output of the + supply must go to the
3. The collector of Q206
CIRCUIT.
is
The suppression
obtained by placing one of var-
is
ammeter
obtained
series
a
bootstrap circuit to supply starting
a
a
reference element, but uses the -12
as a reference.
as
is
returned to ground. The
connected between the outputs of the
of the proper phase, then the base of tran-
is
is
at
the junction of the resistors
one half of
is
connected to
series
attached to the base
returned to
pass tran-
a
and
pass
zener
a
5
same
re-
as
5. Transistor Q203 acts
by sensing the voltage drop across resistor R206.
On overload the voltage drop across R206 causes 4203
to turn on which clamps the base of Q202 to the out-
a
put, thus limiting the maximum current drain.
b. -12
by diodes D202 and D204,
and applied to the collector of the series pass transistor, 4208. Resistor R213 and zener diode 0206
form
amplifier,
base of 4213
potentiometer R222 which
put voltage.
of amplifier 9211 which drives the base of the
Darlington amplifier, 4209, which drives the base
the
as
c.
either the
of R108
sion resistors,
The other end of the resistor
input of the
Volt
Supply.
1.
The secondary of transformer T201
a
bootstrap circuit to supply starting current.
2. The base of Q212, one-half of
3. The collector of Q212
series
4. Transistor Q210 acts as an overload protection
described in paragraph 5 above.
Current Suppression.
1.
is
referenced to zener diode D208. The
is
connected to the center tap of
pass transistor, Q208.
The Potentiometer, R108,
+
or - supply by
is
attached to one of the current suppres-
RlOl
through R107, selected by S102.
ammeter.
an overload protection
is
filtered by capacitor C205
a
sets
the value of the out-
is
attached to the base
is
connected to
S104.
The
is
attached to the
rectified
differential
center tap
of
4. The collector of 4204 drives the base of the
Darlington amplifier, 4202, which drives the base
of the
0272
series
pass transistor, 4201.
2. The magnitude of the suppression
mined by the setting of the potentiometer which
varies the voltage to the resistor.
is
deter-
7
SERVICING
MODEL
414s
SECTION
4-1. GENERAL. Section 4 contains the maintenance and
troubleshooting procedures for the Model 414s Picoam-
meter. Follow these procedures as closely as possible
to maintain the performance of the instrument.
4-2. SERVICING
resistors,
ly every six months for specified accuracy. Except for
this the Model 414s requires no periodic maintenance
beyond the normal care required of high-quality elec-
tronic equipment.
4-3. PARTS
a. The Replaceable Parts
the electrical components of the Picoammeter. Replace
components only
placements which meet the specifications.
b. The
specially selected and matched; order only as a plug-
in unit, part number
Inc.
4-4. TROUBLESHOOTING.
a. The Procedures which follow give instructions for
repairing troubles which might occur in Model 414s.
Use the procedures outlined and use only specified
MOS
SCHEDULE,
R121
and
R122,
REPLACEMENT.
as
necessary.
FET input transistors,
23734A,
The value of the high-rnegohm
should be checked approximate-
List
in Section 7.describes
Use
only reliable re-
QlOl
and
from Keithley Instruments,
Q102,
4.
are
SERVICING
replacement parts. Table 5
ded for troubleshooting. If the trouble cannot be
readily located or repaired, contact Keithley Instru-
ments, Inc., or its representative.
6
b. Table
might occur. If the repairs indicated in the table
do not clear up the trouble, find the difficulty
through a circuit-by-circuit check, such as given in
paragraph 4-5. Refer to circuit description in Sec-
3
tion
determine their function in the circuit. The complete
circuit schematic,
4-5.
power supplies. The typical voltage values, given
on the schematic, are referenced to chassis ground.
Zero the Model 414s meter and make measurements
a Model 153.
with the
this occurs, adjust the front panel
or, if necessary, the Coarse Zero Potentiometer,
located on the
spect all PC boards for a possible break in the tapes.
If
to
PROCEDURES
a. If the instrument
b.
At
these appear all right proceed with step c.
contains the more common troubles which
find the more critical components and to
223943,
TO
GUIDE
times, the meter
METER
Switch in the
PC
board. If this does not work, in-
lists
equipment recommen-
is
in Section
TROUBLESHOOTING.
will
not operate, check the
will
not zero on any range
ZERO
CK
position. If
ZERO
7.
ADJ
Control
.
with
R128,
TABLE
Equipment Recommended for Model 414s Troubleshooting and Calibration. Use these instruments or their equivalents.
I
Keithley Model
reading,
Hewlett Packard 202A Function Generator Rise time check.
Keithley Instruments Model 153 Microvolt-Ammeter, General circuit checking.
10
racy, float f500 volts off ground.
Keithley Instruments Model
10-14 to 10-4 ampere.
Keithley Instruments Model
Keithley Instruments Model515AMegohm Bridge. Verify high megohm resistors in Range Switch.
Keithley Instruments Model
Voltmeter;
Shielded resistors of different values, and shielded Rise time check.
50
I
.,'.ronix Model
L
pV to
pF
and
10
megohm input resistance.
1000
100
500
Instruments use
163
Digital Voltmeter,.
200
Mfl
V,
pV to
pF polystyrene capacitors.
561A
input resistance,
261
Picoampere Source; Source to calibrate current.
370
Recorder Monitor drift.
662
500
Oscilloscope Noise and rise time check.
Guarded Differential Calibrate meter zero.
V,
*O.Ol%.
~~
20.1%
of General calibration.
*l%
accu-
5.
c
a
02 72
SERVICING
6
MODEL
414s
Excessive zero offset
Excessive offset current
Cannot zero on any range
Meter
range settings
One of ranges out of
specification
Excessive drift on
ranges when using current suppression.
Excessive noise when
using current suppression
Excessive drift on one
range when using suppress ion
?-
c. Amplifier.
Difficulty
off scale on one of
all
~~
Probable Cause
Input transistors may be defective
Power supply voltage low
Excessive temperature fluctuations
or defective input transistors
Refer to paragraph 4-5.
Faulty range resistor
Defective range resistor
Power supplies drifting
Power supplies noisy or not
regulating
One of suppression resistors
drifting
d. Power Supplies.
Solution
Check
QlOl
and 4102; replace If faulty.
Check power supply
Check
QlOl
and 4102; replace if faulty.
Refer to paragraph 4-5.
Check resistor; replace if faulty.
Check resistor; replace if faulty.
Check power supplies.
Refer to paragraph 4-5d.
See paragraph 4-5d.
Check resistor; replace if faulty.
1.
To
check the amplifier, disconnect the feed-
back loop by removing Q106, D102, D105 and R129 from
the PC board. Check diodes D102 and D105.
2. Connect
a
Model 153 between
the
bases of 9103
and Q104. Adjust Coarse Zero Potentiometer, R120,
and front panel
be difficult to reach
sufficient to be able to swing through zero in
smooth manner). If this
and Q104 from the circuit and repeat the
ZERO
ADJ
Control for a null (it may
a
steady null; however,
is
not possible, remove Q103
same
it
is
a
process.
If null can now be reached, replace Q103 and Q104.
If
it
cannot be reached,
3. Check the next stage, QlOS, by placing
QlOl
and Q102
are
faulty.
a
Model
153 from the collector end of R128 to ground. Adjust the Model 414s Zero Controls for
this cannot be accomplished, check
ble open by shorting
can now be reached,
it
with a clip lead. If null
DlOl
is
open and should be
a
null. If
DlOl
for a possi-
re-
placed. If null cannot be reached, replace Ql05.
at
4. If null can now be attained
of Ql05, the trouble
is
in the output stage and
the collector
Q106 should be replaced. If this does not cure the
trouble, carefully check
with the output stage
all
-
the diodes associated
D102, D103, D104 and D105.
1.
As
a
voltage to the
Q208. If they are within
proceed
2.
preliminary check, measure the input
as
series
below.
pass transistors, 4201 and
510%
of nominal value,
Check for a possible short on the output by
measuring the drop across resistors R206 and R215.
If the drop
is
likely that a short exists.
is
greater than .5
or
-6
volt then
it
NOTE
An important point to
volt supply derives
remember
its
regulation from the -12
is
that the +12
volt supply. Therefore, if the -12 volt supply
is
not working, the +12 volts
will
not regulate.
Thus, the -12 volt supply should always be check-
ed first.
3.
If no short exists the faulty component can
usually be isolated by making
a
point-by-point
check of the voltages indicated on the schematic.
02
72
9
CALIBRATION
MODEL
414s
SECTION
5-1.
GENERAL.
a.
The following procedures are recommended for cali-
brating the Model 414s.
in Table 5. If proper facilities are not available or
if difficulty
ments, Inc., or
tory calibration.
b. If the Model 414s
after the calibration, follow the troubleshooting procedures or contact Keithley Instruments, Inc., or
representatives.
5-2. PRELIMINARY PROCEDURES.
a. Make sure the
on the
Set
Potentiometer, R128, and
R139, near mid-range.
set the
rear
the Front Panel Controls as follows:
Set
b.
c. Zero the
d. Plug the Model 414s into a 117 volt source and
1.
should read on scale for either polarity
Adjust the Coarse Zero Potentiometer for a zero indication on the
2. If the Coarse Zero Potentiometer, R128, can
not zero the
on the
halves of the heat sink must be insulated in order
for the Coarse Zero potentiometer to function properly.
is
encountered, contact Keithley Instru-
its
panel
are
RANGE
Switch
METER
Switch POWER OFF
ZERO
ADJ.
SUPPRESSION
the
DC
Bal Potentiometer, R127, Coarse Zero
meter
METER
Switch to
If the Model 4145
meter.
meter,
MOS
FET transistors,
Use
the equipment recommended
representatives to arrange for fac-
is
not within specifications
1
MA - 1 V and 117-234 V Switches
set
to
1V
and 117V respectively.
10
MILLIAMPERES
Control Mid-range.
(MAX)
with the Mechanical Zero Control.
ZERO
check for a shorted heat sink
OFF
Meter
Cal.
Potentiometer,
CK.
is
operative, then the meter
QlOl
and Q102. The two
(+
or
5.
its
-).
CALIBRATION
5-3. POWER SUPPLY
points for the Power Supplies.)
a.
Check the positive and then the negative 25 volt
supply by connecting the Model 163 across capacitors
C201 and C202 respectively (Figure 6). The voltage
should be plus and minus 25 volts 22 volts respectively. The ripple in each case should be less than
3 volts peak-to-peak.
For all these power supply checks make sure the
Model 163
test
points (Figure 6).
b. Check the positive and then the negative 25 volt
supply by connecting the Model 163 across capacitors
C201 and C205 respectively (Figure 6). The voltage
should be plus and minus 26 volts 22 volts respectively. The ripple in each case should be less than
3
volts peak-to-peak.
c. Check the positive and then the negative
supply by connecting the Model 163 across capacitors
C204 and C207 respectively. Adjust the
ply to -12.0 volts with the 212
R222. The voltage for the +12 volt supply should be
+12 volts 20.2 volt. The ripple in each case should
be less than
d. Monitor the plus and minus
the line voltage
volts ac. The voltage change of the plus and minus
12 volt supplies should be
Turn the Model 414s off and piepare the Pico-
e.
ammeter for 234 volt, 50 Hz operation. Plug the Model
414s into a 220 volt ac, 50 cycle line and check the
positive and negative 25 volt supplies per paragraph
5-3b above. The same readings as in subparagraph b
above should be obtained except that an additional
volt tolerance should be allowed for each
ference between 234 volts ac and the actual line voltage.
CHECK.
is
connected between ground and the
2mV
peak-to-peak.
is
changed from 105 volts ac to 125
(See Figure 6 for test
NOTE
V
Adj. potentiometer,
12
volt supplies as
less
than 3
mV.
-12
10
12
volt sup-
volt dif-
4
volt
?
1
TABLE
The Table
turing the location and the paragraph describing the
adjustment.
Control Desig. Ref. Paragraph
DC
Bal. 5-2, 5-4
Coarse Zero 5-2, 5-4
Meter
+12V Adj R222 7 5- 3
-
7. Model
lists
all internal controls, the figure pic-
Cal 5-2, 5-6
414s
Internal Controls
Circuit Fig. Refer to
10
5-4. MOS FET
Set the Picoammeter
a.
eres and the
b. Set the front panel
imately mid-range and adjust the Coarse Zero Potentiometer, R128, for
c. Connect the Model 163
and adjust the
dication of -5.4 volts 20.2 volt.
CURRENT
METER
Switch to
a
DC
BAL
ADJUST.
RANGE
Switch to
ZERO
CK.
ZERO
ADJ.
zero indication on the meter.
DVM
Potentiometer, R127, for an in-
across resistor R130
10
x10m3 amp
Control to approx-
02
72
,
MODEL 414s
CALIBRATION
AND
5-5. OFFSET
a.
To check the offset:
1.
-.
r
5-6.
the Model 261 Picoampere Source to the Model 414s
PUT Receptacle and connect the Model 163
OUTPUT Receptacle.
Set the Picoammeter
AMPERES and the METER Switch to ZERO
INPUT Receptacle and connect the Model 414s to the
Model 163
When checking the offset noise,
the Model 414s cover
2. If necessary, adjust the
for zero volts
3.
Set the
that the output remains
front panel
4. Set the
remain.within 210 millivolts.
b. To check the noise:
1.
Connect the Model 414s OUTPUT Receptacle to
the Model 561A Oscilloscope.
2. Set the
voltage from 105 volts
put noise should be
on
peak
a.
all ranges.
METER
Set the
NOISE CHECKS.
DVM.
at
RANGE
ZERO
METER
METER
AND
lMA
RANGE
RANGE
Switch
CK.
NOTE
is
on.
the output.
Switch to
at
ADJ.
Switch to
Switch to t and vary the line
less
OUTPUT
Switch to 1 MICROAMPERE. Connect
zero volts, adjusting the
Control if necessary.
ac
to 125 volts ac. The out-
than
CALIBRATION.
make
ZERO
ADJ.
.1
x
lO-'A.
t.
The output should
10
millivolts peak-to-
to
10 x
Cap the
sure
Control
,Make sure
DVM
to the
IN-
b. 6Set the Model 414s
10- ampere with the Model 261. If necessary, adjust
ZERO
ADJ.
the
output.
c. Adjust the
scale
full
d. Load the Model 414s output with
sistor and
e.
Adjust the
that the output voltage can be adjusted
volt either side of 1.5 volts.
f. Remove the
Switch to
g. Set the
output if necessary.
RANGE
5-7.
a.
Connect the Model 4145 INPUT ReceFtacle to the
Model 261. Connect the OUTPUT Receptacle to the Model
163
DVM.
b.
Check the full-scale accuracy of all positions
the
RANGE
puts to ensure proper operation of both polarities
various curr nt input levels. Chec the accuracy of
the 10 x 10
of full scale
Ch_e§k the accuracy of the
10
A
ranges to 24% of full scale
volt 240 millivolts).
Control for exactly 1,000 volt at the
meter
set
the
1
V.
METER
ACCURACY
Switch.
-9
A
through the
at
METER
Switch to + and apply
Meter
Cal
deflection.
1
rear
1.5
Switch to
Check both positive and negative
the output (1.O-golt
Potentiometer, R139, for
V
-
1
MA
Switch to 1 MA.
panel
1
MA
kilohm load and
ZERO
CHECK.
10
x 10
3
x 10
a
CAL Control and note
set
CK
and re-zero the
-b
A
ranges to 22%
220
A
through the
at
the output (1.0
1.5 kilohm
at
least
the
1
millivolts).
V
0.1
-
.1
re-
1
in-
at
x
MA
on
I"
- - - - - - - -
series
r1
iK
resistors
'--,,--,,,,
FIGURE
tors or capacitor, UHF-Tee and the Shunt Capacitor.
0272
5.
Test
Set-up for Model 414s
Rise
Time
Check
-
-1
UHF
shunt
capacitor
2
-
-
on
all
ranges.
I
I
b14A
U
a
561,\
I
Be
sure to properly shield the series resis-
11
CALIB.WTION
TIME
5-8. RISE
Model 4145 requires two different
s t up
first
-5
1
x 10 A through
up-4~ for checking the
10
a.
test
202A Function Generator,
ing in value from 3 kilohms to 300 megohms (See Table
8),
capacitor, the Model 414s and the Model 561A Oscilloscope. The oscilloscope used must be dc coupled.
TABLE
through 10 x 10
414s
frequency settings, the
RANGE
time
Model 414s Generat or Maximum
RANGE
-
A
and below.
1 x 10-3A
fixture
1.
Equipment used (Refer to Table 5): The Model
a
UHF Tee connector, a
8. Model-614S
RANGE
Switch setting, and the maximum allowable
.
Switch Series Frequency
Setting Resistors (Hz) (milliseconds
CHECK.
is
for checkQg the
through
as
illustrated in Figure 5.
Switch settings, the Function Generator
To check the
10
x 10 A ranges. The second
rise
times
10
x
lO-’A
six
500
Rise
A
Ranges. The Table gives the Model
Time
series
Function
rise
time
test
set-ups. The
rise
times
on
the ranges 1 x
ranges.
shielded resistors rang-
pF polystyrene shunt
Check for 1 x 10-3A
resistor used for each
of the
on
the
Set the
Rise.
Time
set-
rise
2. Procedures:
a) Apply
across the capacitor, through the UHF Tee to the
Model 414s INPUT Receptacle. Monitor the Model
414s output with the Model 561A. Use the proper
Model 202A frequency setting
Table 9.
Adjust the Model 202A amplitude control
b)
needed to obtain 2 volts peak-to-peak at the Model
414s output. Check the 10
figures shown in Table 9.
TABLE
9. Model 414A Rise Time Check for 1 x
and
.1
x lO-9A Ranges.
RANGE
414s
frequency settings, and the maximum allowable
time.
Model 414s Function Generator Maximum
RANGE
Switch
I
Setting (Hz) (mi
1
.I
10-9 0.25 750
5-9. DRIFT VERIFICATION.
MODEL
414s
a
triangular wave from the Model 202A
as
indicated in
as
-
90%
rise
time to the
Switch settings, the Function Generator
The Table gives the Model
lO-’A
rise
Rise
Frequency
1.0
lli
Time
seconds
150
1
*
)
-
1
~o-~A
.1
10-3~
10 x 10-6A
1
x 10-6A
.i
x
10-6~ 30
10
10-9~ 300
2. Procedures:
a) Apply
Function Generator across the selected
sistor, through the UHF
PUT Receptacle. Observe the output of the Model
414s with the Model 561A.
b) For each Model 414s range, use the Model 202A
frequency setting and the series resistor indicated in Table 8.
c) Adjust the Model 202A amplitude control
needed to obtain 2 volts peak-to-peak
414s output. Check the 10
figures shown in Table 8.
1
x
b.
fixture up
shielded 50 pF polystyrene capacitor should be sub-
qtituted for the series resistors between the Function
.--?rator and the
lO-’A
as
3 kQ 250
30 kQ 250
300 kQ 250
MQ
3
MQ
Ma
a
square wave from the Model 202A
2.5 50
2.5 90
2.5 130
Tee
to the Model 414s
less
less
less
series
than
than
than
re-
IN-
as
at
-
90%
rise
and
.1
x
lO-’A
illustrated in Figure 5, except that a
UHF
‘~CP-.
ranges.
the Model
time
to the
Set this
test
1
1
1
a. Shunt the Input of the Model 414s with a 10-kilohm resistor with the
and the
Using the shunt increases the sensitivity 100 times.
Set the Recorder attenuator to
drift full scale) or
Control for near zero volts output. The
trol
100
negative,
drift
microvolts per
ginal or
to
drift. If this
the drift for an additional 24 hours and calculate
weeks drift
METER
Switch
While
doing the drift run make sure the Model
414s cover
b. Connect the Model 370 Recorder to the Model 414s.
c. Set the
is
times.
d. After
700
e.
In
a
steep drift slope during the early part of the
METER
very sensitive with the sensitivity increased
Set the
a
10-minute warm-up, the Model 414s may
microvolts per 24 hours plus or minus
‘C
some cases, the 24-hour drift may appear
it
may be slightly out
as
follows:
RANGE
set
is
on.
0.3
Switch to + and adjust the
METER
change in temperature.
is
so,
Switch
to + or
NOTE
volts
Switch to - if the drift
it
may be desired to continue
set
-,
as necessary,
1
volt (10 millivolts
(3
mV
of
specification due
to 1 x 10’6A
full scale).
ZERO
ZERO
ADJ
500
Con-
mar-
ADJ
is
-,
a
1.
Equipment Used: This
equipment
of
the
this set-up serves a
resistors in the previous
1“
IL
of
the previous set-up with the exception
50
pF polystyrene capacitor. The capacitor in
similar
test
function
test
set-up uses the
as
set-up.
the
series
same
1.
Multiply the drift during second 24-hour periot?
times
6 and add the drift noted during the first 24-
hour period.
2.
Total drift should not exceed 5
mV.
0272
MODEL
414s
r
5-10. SUPPRESSION
a.
Cap the input
output to the Model 163.
b.
Set the front panel controls
RANGE
Switch
METER
c. Adjust the SUPPRESSION, FINE Control for
scale
on
the 163 and adjust the SUPPRESSION, FINE Control
for maximum suppression.
output voltage observed
greater than
d. Set the front panel controls
Switch
ZERO
ADJ.
SUPPRESSION,
SUPPRESSION, Polarity Control
meter
deflection. Monitor the output voltage
RANGE
Switch
METER Switch
ZERO
ADJ.
SUPPRESSION,
SUPPRESSION, Polarity Control
CHECK.
of
the Model 414s and connect the
Control Mid-range
MAX
AMPERES Switch 10-3
At
maximum suppression, the
on
1.1
volts
Control Mid-range
I4AX
the Model 163 should be
(10%
over-range).
AMPERES Switch 10-4
as
follows:
as
follows:
1
(+)
(-)
.I
(+)
(-1
10-3
a
10-3
full
CALIBRATION
set
g. Then,
RANGE
METER
ZERO
SUPPRESSION,
SUPPRESSION, Polarity Control
Repeat the procedures outlined in sub-paragraph c,
and e above.
h. Set the front panel controls as follows:
RANGE
METER
ZERO
SUPPRESSION,
SUPPRESSION, Polarity Control
With the Model 261 apply
input.
Model 561A oscilloscope.
and adjust the SUPPRESSION, FINE Control
the input signal
.I
Monitor the output with
Set the SUPPRESSION,
i.
10-9,
the front panel controls
Switch
Switch
ADJ.
Control Mid-range
MAX
AMPERES Switch 10-3
Switch
Switch
ADJ.
Control Mid-r ange
MAX
AMPERES Switch OFF
10-8
ampere to the Model 414s
a
5
MAX
AMPERES Switch to 10-8
as
the
RANGE
Switch
as
follows:
1
10-3
(-)
(+I
10
10-9
(+I
(+I
mV/div ac coupled
to
is
buck out
changed to
d
e.
Adjust the SUPPRESSION, FINE Control for a full
meter
scale
f. Using the method described in paragraph
test
the suppression for each setting
Switch, using corresponding settings of the SUPPRESSION,
MAX
AMPERES Switch. The output voltage noted
Model
deflection. division). Output noise observed
b
above,
RANGE
on
the
163
should not vary more than 54%.
of
the
j.
Meter
noise should be
less
than
should be
low frequency component.
10
less
than
2%
mV
on
peak-to-peak, excluding any
(one minor
the oscilloscope
0272
13
CALIBRATION
!IODEL
4145
14
FIGURE
6.
Chassis,
Top
View.
0272
PIC2EL
414s
CALIBRATION
a272
FIGURE
7.
Component
Layout,
PC180.
15
ACCESSORIES
MODEL
414s
SECTION
6-1.
GENERAL.
can be used with the Model 414s to provide additional
convenience and versatility. operating information.
De sc
r
ip
t
ion
The Model 6106 contains a group of the most useful Description
leads and adpaters for low current measurements.
components are housed in a rugged carrying case with Cable,
individual compartments. Cable, 24",
The following Keithley accessories 6-2.
Model 6106 Electrometer Connection
:
6.
All
ACCESSORIES
OPERATING
Manual
Parts
is
List:
30",
Connector,
Adaptor,
Adaptor,
Adaptor Tee,
Adaptor, Binding Post
The two cables (Items 1 and 2) are coaxial shielded
leads useful for connections where low noise is essential.
nect two instruments having
cable (Item
under test through the use
post adapter gives easy access to the electrometer
"high" terminal. Two
permit cables to be connected together.
connector simplifies galvanometric current measurements
when using a current source and electrometer or pico-
ammeter. Adapters (Items
version from
UHF
UHF
The 24" cable (Item 2) can be used to intercon-
INSTRUCTIONS.
supplied with each accessory giving complete
Kit
UHF
to clips
UHF
to
UHF
1)
UHF
to
UHF
to
BNC
to
BNC
UHF
to
can be used to connect to the circuit
UHF
to
A
separate Instruction
Item Keithley
UHF
UHF
receptacles. The
of
clip leads. A binding
UHF
female couplers (Item
4
and
BNC
terminations.
5)
No.
1
2
3
4
5
6
7
Part No.
19072C
18265C
cs-5
CS-115
CS-172
CS-171
19071B
30"
3)
UHF
The
are useful for con-
"tee"
Model 261 Picoampere Source
Description
The Model 261
3
with
ampere to
eight decade ranges. Accuracy
-
+1.6% exclusive of input drop considerations.
Application
The Model 261
brating picoammeters and electrometers.
used as an accurate current source for zero suppression
and for galvanometric measurements.
16
:
is
digit resolution. The output ranges are
1.1
an accurate picoampere current source
x
10-4 ampere, positive or negative, in
:
is
a secondary standard for use in
is
rated from 2.25% to
It
can also be
cali-
3
0272
MODEL 414s
ACCESSORIES
r
Description:
The Model 4003A.i~ a rack mounting kit with overall
dimensions, 5-1/4 inches high
top covers are provided for use with either
13 inch deep instruments.
Application
The Model 4003A converts the instrument from bench
mounting to rack mounting. It is suitable for mount-
ing one instrument in one-half of a standard 19-inch
rack.
:
x
19 inches wide. Two
Model 4003A Rack Mounting Kit
10
inch or
Parts List:
Item
No.
1
2
3
4
5
6
7
8
Top Cover,
Panel Adapter Plate
Angle Support
Screw,#lO
Connecting Plate
Screw,
Angle
Top Cover, 13"
Description
1/10
10"
x
x
318"
1/2"
Qty. Per Keithlev
Assembly
1
1
1
4
1
4
1
1
Part
No.
18554B
17452B
17476A
---
19126A
---
14624B
20015B
Model
Description
The Model 4004A is a rack mounting kit with overall Item Qty. Per Ke it h ley
dimensions, 5-114 inches high x 19 inches wide.
p
top covers are provided for use with either
or 13 inch deep instruments.
Application
The Model
r
mounting to rack mounting. It is suitable for mount- 9 Zee Bracket
ing two instruments in a standard 19-inch rack.
02
72
:
:
4004A
converts the instrument from bench
4004A
10
Dual Rack Mounting Kit
Parts List:
Two
inch
No.
1
4
5
6
7
8
10
Description As semb
Top Cover,
Screw,
Connecting Plate
Screw,
Angle 2
Top Cover,
Plate (not
110
1/10
10"
x
1/2
x
1/2
13"
shown)
2
8
1
4
2
1
1
1
y
Part
No.
18554B
---
191268
---
14624B
20015B
19144A
17454A
17
ACCESSORIES
MODEL'
4145
Models 240A, 244, 245, 246 Voltage Supplies
s
c r i
pt
ion
De
:
Keithley voltage supplies are highly-stable, low-noise
23100
power supplies for voltages up to
Application
:
volts dc.
Keithley voltage supplies are commonly used with pico-
of
ammeters in the measurement
resistance, light levels
(photomultipliers), and radiation intensity (ion chambers).
These high voltage supplies have been designed to
operate with the Keithley line
picoameters and resistivity accessories.
of
electrometers,
A
typical
application is shown using the Model 414s (or 414A)
and the Model 240A in a photomultiplier experiment.
Output Ranges
Model
2 40A
44
2
2 45
46
2
:
No.
Voltage
0
to +12oov
-200 to -2200v
0
to +21oov
0
to
~3100V
?
Model 4104 Electronic Trip
The Model 4104 is an electronic trip installed in the
picoameter to provide automatic current control.
Combinations
of
high,
low, 2 polarity, and latching
is available.
18
Model 4109 Polarizing Supply
The Model 4109 provides
volts at 1
mA
for appli-
+300
cations requiring a stable voltage source. The Model
4109 can be ordered installed in the picoameter if
desired.
0172
MODEL
414s
P
SECTION
7-1.
REPLACEABLE PARTS
List
describes the components of the Model 414s. The
List
gives the circuit designation, the part descrip-
a
tion,
number and the Keithley Part Number. The
indicates the figure picturing the part. The name and
address
column
7-2.
suggested manufacturer, the manufacturer's part
of
the manufacturers listed in the "Mfg. Code"
are
in Table 14.
HOW
TO
ORDER
a. For parts orders, include the instrument's model Instruments, Inc.
LIST.
PARTS.
The Replaceable Parts
last
TABLE
7.
12.
REPLACEABLE PARTS
and
serial
cuit designation and
structural parts and those parts coded for Keithley
column
Abbreviations and Symbols.
manufacture (80164) must be ordered through Keithley
Instruments, Inc., or
a
ing
completely describe the part,
location.
b.
resentative or the
REPLACEABLE
number, the Keithley
part not listed in the Replaceable Parts
Order parts through your nearest Keithley rep-
a
description of the part.
its
Sales
Service Department, Keithley
Part
Number, the cir-
representatives. In order-
its
function and
PARTS
All
List,
its
Fig.
GCb
k
P
MODEL
MY
MY
CerD
CerD
CerD
CerD
CerD
CerD
CerD
CerD
M
Mfr.
Mtf
MY
414s REPLACEABLE PARTS
EA1
F
Circuit Mfr. Mfr. Keithley Fig.
Desig. Value Rating Type Code Desig. Part
ClOl
c102
C103
C104
C105
C106
C107
C108
c109
CllO
Electrolytic, Aluminum
Farad
(Refer to Schematic Diagram 22394E for circuit designations.)
.25 PF
.1
PF
-02 PF
pF
.0.2
.0047 PF
-0022 PF
680
pF
.01
PF
.0033 pF
.0022 PF
400
400
1000
1000
1000
1000
1000
to00
1000
1000
'V
V
V
v
v
v
v
v
v
v
Figure
Glass
kilo (lo3)
micro (10-6)
Mega (lo6)
Manufacturer
Xetal
Mylar
CAPACITORS
13050
13050
56289
56289
56289
72982
71590
56289
56289
72982
Enclosed carbon
Film
LIST
SMlA C73-. 25M
SMlA
10ss-s20 C22-. 02M
10ss-s20
10SS-D47 C22-.0047M
811000X5F0222K C22-.0022M
DD-681 C22-680P
loss-
10SS-D33 V33-.0033M
811000X5F0222K C22-.0022M
s10
n
P
Poly
Ref.
V
W
War
ohm
pic0 (10-12)
Polystyrene
Reference
Volt
Watt
Wirewound Variable
No.
C73-.
1X
C22-
.02M
C
2 2-
.
0
1M
Ref.
Clll
c112
C113 47 pF
r
C114 22 pF
C115 .0068
*Nominal value.
680 pF
220 pF
uF*
1000
500
500
500
500
v
V
V
V
V
CerD
Poly
Poly
Poly
CerD
71590
71590
71590
71590
72982
DD-681
CPR- 220
CPR-47J C138-47P
CP
851-25U0-682M C22-.0068M
R-
J
2
2
J
C2
2-6801)
C138-220P
C138-22P
r
0675
19
REPLACEABLE PARTS
MODEL 414s
T
CAPACITORS (cont'd)
Circuit Mfr. Mfr.
Des
ig
.
c201
c202
C203
C204
C205
C206
C207
Circuit
Desig. Type
DlOl
D102
D103
D104
D105
D106
D107
D201
D202
D203
D204
D205
Value Rating Type Code Desig
100
IJF 40
.02 lJF
.02 iJF
100
iJF
100
lJF
.01
~JF
100
pF
Silicon
Silicon
Silicon
Zener
Silicon
Silicon
Silicon
Silicon
Silicon
Silicon
Silicon
Zener
V
1000
1000
40
V
40
V
1000
40
V
v
v
v
EA1
CerD
CerD
EA1 73445
EA1
CerD
EA1
Mfr.
Code
01295
02735
02735
84970
02735
01295
01295
01295
01295
01295
01295
12954
73445 C437AR/G100 C150-100M 7
56289
56289
73445
56289
73445 C437AR/G100
DIODES
Mfr.
Desig.
1N645
1N3255
1N3255
VR47
1N3255
1N645
1N645
1N645
18645
1N645
1N645
1N706
loss-
10s
C437AR/G100 C150-100M
C437AR/G100 C150-100M 7
10
s
Kei
,
s
20 C22-. 02M
s-s20 C22- .02M
s-s20
thley Fig.
Part No. Ref.
C22- .01M
C150-100M 7
Kei
thley
Part No.
RF- 14
RF-
17
RF-17
DZ-30
RF-17
RF-14
RF-14
RF-14
RF-14
RF- 14
RF- 14
DZ-1
7
7
7
7
Fig.
Ref.
7
7
7
;-
7
7
D206
D207
D208
Circuit Mfr. Mfr, Keithley Fig.
Desig. Description Code Desig
21850B
DS201
F201 (117V)
F201 (234V)
5101
PlOl
5102
---
---
5103
---
MlOl
P201
Zener
Silicon
Zener
MOS FET Input Plug-in Card
Pilot Light, Neon
of
A
5102
mate
Fuse, Slow blow, 1/8
Fuse, Slow blow, 1/16
Printed Circuit Contacts
Printed Circuit Contacts,
Receptacle, UHF, INPUT
Plug, UHF,
Cap
Receptacle, Microphone, OUTPUT
Plug, Microphone,
Meter
AC
Power Cable, 6 feet
mate
12954
01295
04713
A
mate
of 5103
1N706
1N645
1N936
MISCELLANEOUS PARTS
80164
91802
71400
7
1400
91662
of
5101
91662
91737
02660
91.737
02660
02660
80164
93656
.
2190
MDL
MD
L
02-005-113-6-200
02-005-111-5-200
6804
83-822
7901
80-PC2F
80-MC2M
46
38-
13
DZ-1
RF-14
DZ-5
Part No. Ref.
23734A 6
PL-28 2
FU-20 3
FU-21
CS-199
cs-200
CS-64 3
cs-49
CAP-4
CS-32 3
cs-33
ME-78 6
CO-
5
7
7
7
1
7
20
0272
~~
SODEL
414s
P
MISCELLANEOUS PARTS
REPLACEABLE PARTS
Circuit
Desig.
Circuit
.
Desig
Description
Rotary Switch,
Knob Assembly, Meter Switch
Rotary Switch
SUPPRESS
Rotary Switch with components, 80164
Suppression
Knob Assembly, Suppression Switch 80164
Rotary Switch
Rotary Switch with components, Range 80164
Knob Assembly, Range Switch
Rotary Switch, Suppression Polarity 80164
Rotary Switch with components, Polarity 80164
Knob Assembly, Polarity Switch 80164
Slide Switch,
Slide Switch,
Knob Assembly,
Knob Assembly, Suppression FINE Control 80164
Transformer 80164
Value Rating Type Code
I
ON
METER
less
components, 80164
less
1
MA
117
1
MA
V
components,
-
1
V
-
234
CAL
Control 80164
RANGE
V
Mfr. Mfr.
Code Desig.
80164
80164
80164
80164
79727
80164
RESISTORS
Mfr.
G326
Mfr. Keithley
.
Desig
Keithley Fig.
Part
No.
SW-244
216608
SW-262
22135B
21660A
SW-243
21848B
21651A
SW-261
22136B
20382A
sw-45
SW-151
16373A
16995A
TR-112
Part
No.
Ref.
2
2
2
2
3
3
7
Fig.
Ref.
P
-
RlOl
R102
R10 3
R104
R105
R106
7
R10
R10 8
R109
RllO
Rlll
R112
R113
R114
R115
R116
R117
R118
R119
R120
R121
R122
R123
R124
R125
1010
109
108
107
106
105
104
10
300
1
kQ
3
kR
10
30
100
300
1
MQ
3MG
10
30
100
109
1010
2
kR
1
kR
1m
R
R
R
R
n
R
R
kR
R
kR
kR
kQ
kR
MR
MR
m
R
R
3%
3%
1%,
2
w
1%,
112
112
112
112
2
w
112
112
112
112
112
w
112
112
112
112
1
w
2
w
112
112
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
1%,
1%,
1%,
5%,
1%,
1%,
1%,
1%,
1%,
1%, 1
1%,
1%,
1%,
1%,
1%,
1%,
3%
3%
1%,
1/2%, 1/2w
1%,
GCb
GCb
DCb
DCb
DCb
DCb
DCb
War
DCb
DCb
DCb
DCb
DCb
EPOXY
DCb
DCb
DCb
DCb
DCb
DCb
GCb
GCb
MtF
MtF
DCb
63060
63060
91637
07716
91637
07716
07716
12697
91637
91637
07716
07716
91637
9 16 37
07716
91637
91637
07716
91637
91637
63060
63060
07716
07716
91637
Rx-
1
Rx-
1
DC-2
DCC
DCF-
1
/
DCC
DCC
62JA
DCF-112
DCF-112
DC
C
DCC
DCF-112
1
MMF-
DCC
DCF-112
1
12
DCF-
DCC
DC-1
DC-2
Rx-
1
Rx-
1
CEC
CEC
DCF-112
lolo
R20~20-109
R14-
lOOM
2
R12-10M
R12-1M
R12-100K
R12-10K
RP
4
2-
10K
R12-300
R12-1K
R12-3K
R12-10K
R12-30K
R150-100K
R12-300K
R12-1M
R12-3M
R12-10M
R13-30M
R14-
10
ON
R20- 109
R20-1010
R61-2K
1-
1K
R6
R12-1M
-
-
-
-
-
-
-
-
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
7
02 72
21
REPLACEABLE PARTS
MODEL
414s
RESISTORS (cont'd)
Circuit Mfr. Mfr. Kei thley Fig.
Desig. Value Rating Type Code Desig. Part No. Ref.
R126**
R127
R128
R129
R130
R131
R132
R133 15
R134
R135
R136
R137 1.2
R138
R139 2
R140
R141
R142
R143
R201
R202
R203
R204
R205
100
5
1
13
18
2
18
2.2
680
4.7
2
,1
1
1
1
27
2.7
47
4.7
47
kn
kn
kn
kn
kn
kn
kn
kn
kn
kn
kn
kn
kn
kQ
kfl
kn
kn
kQ
kn
kn
kn
kfl
10%) 114
20%) 2
lo%,
1%,
1%)
20%) 0.2 W
1%,
10%.
10%)
lo%,
lo%,
lo%,
1%,
20%,
1/2%, 112 W MtF 07716 CEC R6
10%)
112%) 112 W MtF 07716 CEC R6
1/2%, 112
lo%,
10%)
lo%,
lo%,
lo%,
w
5
w
112
112
112
112
112
112
112 W
2
w
112
2
w
5
w
112
112
112
112
112
W
w
w
w
w
w
W
w
w
W
w
w
w
Comp
War
War 71450
DCb 91637
DCb 07716
CompV 71450
DCb 07716
Comp 01121 EB
Comp 01121
Comp
Comp
Comp
DCb 07716
War 7 1450
War 71450 AW RP34-1K
W
MtF
Comp
Comp
Comp 01121
Comp 01121
Comp 01121
01121 CB
71450 1NS-115
01121 EB R1-680 7
01121 EB Rl-4
01121
07716 CEC R6
01121 EB R1-27K
01121
AW RP34-1K 7
DCF-112 R12-13K 7
DCC R12-18K 7
DC C R12-18K 7
EB R1-2.2K 7
HB R3-1.2K 7
DCC R12-2K 7
1NS-115 RP50- 2K 7
EB R1-2.7K 7
EB R1-47K 7
EB Rl-4.7K 7
EB R1-47K 7-
R76-100K 6
RP50- 5K 7
RP3
R1-15K
1-
2K 2
I
7K 7
1-
1K 7
1-
1K 6
1-
1K
7
3
6
7
9
R206
R207
R208
R209
R2
10
R211
R212
R213
R214
R215
R2 16
R217
R218
R2 19
R220
R221
R222
R223 91
R224
Circuit Mfr. Mfr. Kei
Desig. Code Desig
Q101**
Q102**
Q103
Q104
Ql05
47
n
4.7
4.7
100
82
kn
4.7
4.7
2.7
47
ka
47
4.7
47
kn
2.7
100
kn
47
22
kQ
10
kn
m
27
w2
ka
ki-2
kn
kn
kn
kn
kn
kn
kn
10%)
112
lo%,
112
lo%,
112
lo%,
112
lo%,
112 W Comp
1/2%, 112
1/2%, 112
lo%,
112 W
10%)
112
10%)
112
lo%,
112
lo%,
112
lo%,
112
lo%,
112
lo%,
112
112%) 112
20%, 2
112%)
lo%,
112
80164
80164
80164
80164
04713
w
w
W
W
W
w
w
w
w
w
w
w
112
w
Comp
Comp
Comp
Comp
W
MtF 07716 CEC R61-4.7K 7
W
MtF 07716
Comp 01121
Comp
Comp
Comp 01121
Comp 01121
Comp
Comp
Camp 01121
W
MtF 07716 CEC R6 1-22K 7
War
W
MtF
Comp 01121
01121 EB R1-47 7
01121 EB Rl-4.7K 7
01121 EB Rl-4.7K 7
01121 EB R1-100K 7
01121 EB R1-82K 7
CEC R61-4.7K 7
01121 EB R1-47K 7
01121 EB R1-47 7
01121 EB R1-2.7K 7
01121 EB R1-100K 7
71450 1NS-115
07716 CEC R61-91K 7
TRANSISTORS
.
2N3904
EB R1-2.7K 7
EB R1-4.7K 7
EB R1-47K 7
EB R1-47K 7
EB Rl-27K 7
Part No. Ref.
20933A
20933A
21675A
21675A
TG-47
RP 5
0-
10
K 7
t
hley Fig.
6
67
7
7
7
?
**
Replace R126,
22
QlOl
or Q102 by ordering Plug-in Board 23734A.
02
72
MODEL
414s
REPLACEABLE
PARTS
Circuit
Desig.
Q106
4201
Q202
4203
4204
Q205
4206
4207
4208
4209
Q210
4211
Q212
Q213
Mfr.
Code
71279
02734
07263
07263
07263
07263
07263
07263
02734
07263
07263
07263
07263
07263
TRANSISTORS
Mfr.
Desig.
ES-5 321
40317
2N3565
2N3565
283565
2N3565
2N3565
2N3565
40319
S17638
S17638
S17638
S17638
S17638
(cont'd)
Kei
Part
TG-54
TG-43
TG-39
TG-
TG-
TG-39
TG-39
TG-39
TG-50
TG-33
TG-33
TG-33
TG-33
TG-
thley
No.
3
9
3 9
3 3
Fig.
Ref.
7
7
7
02 72
23
REPLACEABLE PARTS
TABLE
13.
Mechanical Parts
List
~
MODEL
7
414s
1)
Chassis
11)
Front Panel
Top Cover Assembly
12)
Cover, Sheet Metal
13) Screws
Handle Assembly
14) Handle
15) Screws 1\6-32
Bottom Cover Assembly
2)
Cover
3)
Fastener
Feet Assembly
4) Feet
5) Ball
Description
x
3/8"
R.H.
Slotted
Quantity
Per Assembly
Kei thley
No.
Part
24021B
21658C
18553B
17131D
---
---
HH-18
---
19 29
8C
19340B
FA-54
---
FE-5
FE-6
Fig.
Ref.
8
8
9
24
6) Screws 118-32
Tilt
Bail Assembly
7)
Bail
8) Right Assembly
9) Left Assembly
10)
Screws 86-32 x 1/4"
x
3/8" Phillips, Pan Head
Phillips, Pan Head
---
---
I
"
L
17147B
19206B
19205B
---
0272
-
~~
MODEL
414s
REPLACEABLE PARTS
cp’
FIGURE
8.
Top Cover Assembly.
03
72
FIGURE
9.
Bottom Cover Assembly.
25
__-
CODE-TO-NAME LIST
TABLE
14.
MODEL
Code List of Suggested Manufacturers. (Based on Federal Supply Code for Manufacturers, Cataloging Handbook
414s
T
H4-1).
01121
01295
02660
02735
04713
07716
12954
13050
Allen-Bradley Corp.
1201
South 2nd Street
Milwaukee, Wis.
53204
Texas Instruments, Inc.
Semiconductor-Components Division
13500
North Central Expressway
Dallas, Texas
75231
Amphenol Corp.
2801
South 25th Avenue
Broadview, Chicago, Illinois
60153
Radio Corporation of America
Commercial Receiving Tube and
Semiconductor Division
Somerville, N.J.
Motorola, Inc.
Semiconductor Products Division
5005
East McDowell Road
Phoenix, Arizona
85008
International Resistance Co.
2850
Mt. Pleasant
Burlington, Iowa
52601
Dickson Electronics Corp.
302
S.
Wells Fargo Avenue
Scottsdale, Ariz.
Potter
Highway
Wesson, Miss.
Co.
51
N.
39191
71450
71590
72982
73445
79727
80164
849 70
91637
91662
CTS Corp.
1142
W. BeardsJey Ave
Elkhart, Ind.
Centralab Division of
Globe-Union, Inc.
932
E. Keefe Ave.
Milwaukee, Wis.
53212
Erie Technological Products, Inc
644
W. 12th Street
Erie, Pa.
Amperex Electronic Co. Division
16512
of
American Phillips Co., Inc.
Hicksville, N.Y.
Continental-Wirt Electronics Corp
Philadelphia,
Pa.
Keithley Instruments, Inc
28775
Aurora Road
Cleveland, Ohio
44139
Sarkes Tarzian, Inc
E. Hillside Drive
Bloomington, Ind.
Dale Electronics, Inc.
P.O. Box
Columbus, Nebr.
609
68601
Elco Corp.
Willow Grove, Pa.
North
63060
71279
71400
Victoreen Instrument Co.
5806
Hough Avenue
Cleveland, Ohio
44103
Cambridge Thermionic Corp.
430
Concord Avenue
Cambridge, Mass.
Bussmann Mfg. Div.
of
McGraw-Edison Co.
2538
W. University St.
St. Louis, Mo.
91737
91802
93656
Gremar Mfg. Co., Inc.
7
North Avenue
Wakefield, Mass.
Industrial Devices, Inc.
982
River Road
Edgewater, N.J.
07020
Electric Cord. Co.
1275
Bloomfield Avenue
Caldwell, N.J.
26
02
72
r-
KEITHLEY
CLEVELAND,
INSTRUMENTS,
28775
AURORA
OHIO
SERVICE
INC.
ROAD
44139
FORM
MODEL
COMPANY
ADDRESS
NO.
Describe problem
readings,
Show
(whether power is turned
,--
.
List the positions
the instrument.
SERIAL
chart
a
block diagram
NO.
and
symptoms using quantitative
P.O.
recordings, etc.)
of
your
of
-
all controls
measurement system including all instruments connected
on
or
not).
NO.
CITY
DATE
STATE
data
whenever possible (enclose
(Attach additional
Also describe signal source.
and
switches
on
both
front
1
R-
sheets
and
rear panels
1
ZIP
as necessary
of
7
h
Ifl
Describe input signal source levels, frequencies, etc.
List
and
161
List
describe
and
describe
all
cables used in the experiment (length, shielding, etc.).
all
other equipment used in the experiment. Give control settings
for each.
Environment:
Where is
out-of-doors
What
Ambient temperature?
7
Other
Additional
please descri be be1
the measurement being performed?
,
etc.
)
power
line
voltage is used? Variation? Frequency?
Information.
ow.
)
OF.
(If
special modifications have been made
Variation?
(Factory,
control
OF.
Re1 . Humidity?
led laboratory,
by
the user,
REV
0774
Loading...