Keithley 169 User manual

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Instruction Manual
Model 169
Digital Multimeter
01979, Keithley Instruments, Inc.
Cleveland, Ohio, U.S.A
Document Number 30161

TABLE OF CONTENTS
SECTION PAGE
1.
2.
3.
4.
5.
GENERAL INFORMATION. .......................
l-l
1.1. INTROOUCTION ........................ 1-l
1.3. FEATURES .......................... l-1
1-5. WARRANTY INFDKMATION .................... 1-2
l-7. CHANGE NOTICES ....................... 1-2
1-9. SAFETY SYMBOLS ....................... l-2
l-11. SPECIFICATIONS ....................... 1-2
OPERATION. ............................ 2-l
2-l. INTRODUCTION ........................ 2-l
2-3. UNPACKING AND INSPECTION .................. 2-l
2-5.
PREPARATION FOR USE. .................... 2-l
2-6.
Installation of Batteries, if required ........... 2-1
2-7.
CONTROLS, INDICATORS AND CONNECTORS. ............ 2-l
2-8.
Display ........................... 2-1
2-10. Front Panel Switches .................... 2-2
2-12. Input Connections. ..................... 2-2
2-14. Tilt Bail/Handle ...................... 2-4
2-16. INITIAL FUNCTIONAL CHECK .................. 2-4
2-18. OPERATING INSTRUCTIONS ................... 2-4
2-20. DC VOLTAGE MEASUREMENT ................... 2-5
2-22. AC VOLTAGE MEASUKEMENT ................... 2-5
2-24. AC OR DC CUKRENT MEASUREMENT ................ 2-5
2-26. RESISTANCE (n) MEASUREMENT ................. 2-6
PERFORWINCE VERIFICATION ..................... 3-l
3-1. GENERAL ........................... 3-l
3.3.
RECOMMENDED TEST EQUIPMENT ................. 3-1
3-5. ENVIRONMENTAL CONDITIONS .................. 3-l
3-7.
PERFORMANCE VERIFICATION PROCEDURE ............. 3-1
3-9. Initial Conditions ..................... 3-2
3-11. DC Volts Checkout. ..................... 3-2
3-12. AC Volts Checkout. ..................... 3-2
3-13. Resistance Checkout. .................... 3-3
3-14. DC Current Checkout. .................... 3-3
3-15. ANALYSIS .......................... 3-3
ACCESSORIES. ........................... 4-l
4-1.
GENERAL ........................... 4-l
4-3.
MODEL 1600 HIGH VOLTAGE PROBE. ............... 4-l
4-5.
MODEL 1651 50-AMPERE SHUNT ................. 4-1
4-7.
MODEL 1681 CLIP-ON TEST LEAD SET .............. 4-l
4-9. MODEL 1682 RF PROBE. .................... 4-1
4-11. MODEL 1683 UNIVERSAL TEST LEAD KIT ............. 4-2
4-13. MODEL 1684 CARRYING CASE .................. 4-2
4-15. MODEL 1635 CLAMP-ON AC CURRENT PROBE ............ 4-2
4-17. MODEL 1691 GENERAL PURPOSE TEST LEAD SET .......... 4-2
4-19. MODEL 1699 SPARE PARTS KIT ................. 4-2
4-21. MODELS 1010 and 1017 RACK MOUNTING KITS. .......... 4-2
THEORY OF OPERATION. ....................... 6-l
5-l.
5-3.
5-6.
5-7.
5-10.
5-12.
5-14.
GENERAL. ................
OVERALL OPERATION. ...........
SIGNAL CONDITIONING. ..........
AC/DC Voltage Measurements .......
AC/DC Current Measurements .......
Resistance Measurements. ........
A/D CONVERTER. .............
........ 5-l
........ 5-l
........ 5-l
........ 5-I
........ 5-I
........ 5-2
........ 5-2
I ii
i i

TABLE OF CONTENTS (Cont'd)
SECTION PAGE
5-16. DISPLAY CIRCUITS ...................... 5-2
5-18. REFERENCE SOURCE ...................... 5-3
5-20. LOW BATTERY DETECTOR .................... 5-3
5-22. INPUT PROTECTION ...................... 5-3
5-24. Voltage Protection ..................... 5-3
5-27. Current Protection ..................... 5-3
5-29. Ohms Protection. ...................... 5-3
6. MAINTENANCE. ........................... 6-1
6-1. GENERAL ........................... 6-l
6-3. CALIBRATION. ........................ 6-l
6-5. Recormended Calibration Equipment. ............. h-l
6-7. Environmental Conditions .................. h-l
6-9. Case Cover Removal ..................... 6-1
6-11. Calibration Adjustment ................... 6-I
6-14. TROURLESHOOTING. ...................... 6-2
6-16. Special tiandling of Static Sensitive Devices ........ 6-2
6-18. Power supply ........................ 6-3
6-20. A/D Converter and Display Driver .............. 6-3
6-22. AC Converter ........................ h-3
6-24. Voltage Divider, Reference Source and Ohms Circuit ..... 6-3
b-26. Current Circuitry. ..................... 6-3
6-31. LIQUID CRYSTAL DISPLAY REPLACEMENT ............. 6-4
6-33. BATTERY REPLACEMENT. .................... 6-9
6.35. CURRENT FUSE REPLACEMENT .................. 6-9
7. REPLACEABLE PARTS. ........................ 7-D
7-I. GENERAL........................... 7-o
7-3. ORDERING INFORMATION .................... 7-D
J-5. FACTORY SERVICE. ......................
7-O
7-J.
SCHEMATIC. ......................... 7-O
7-9. COMPONENTS LAYOUT. ..................... 7-D
J-11. MODEL 1699 SPARE PARTS KIT ................. 7-O
ILLUSTRATIONS
FIGURE TITLE JhGJ
l-l
2-l
2-2
2-3
4-l
4-2
4-3
4-4
5-I
5-2
5-3
5-4
6-1
6-2
6-3
6-4
6-5
7-l
Model lG9. ....................... I-1
Installation of Batteries. ............... 2-o
Model 169 Front Panel Display. ............. 2-O
Operating Controls ................... 2-3
High Voltage Probe and RF Probe. ............ 4.2
Current Probe and Current Shunt. ............ 4.3
Convenience Cable and Connectors ............ 4.3
Carrying Case and Hack Mounting Kits .......... 4.4
Model 169 DMM Overall Signal Flow Block IDiagram. .... 5-5
Simplified AC/DC Voltage Measurement .......... 5-6
Simplified AC/DC Current Measurement ..........
5-J
Simplified Resistance Measurement. ........... 5-8
Calibration Adjustment Location. ............ 6-2
LCD Assembly ......................
6-4
Integrator Waveform. .................. 6-6
AC/DC Converter Waveform ................
6-J
Current Fuse Removal/Replacement ............ 6-9
Covers and Panels. ...................
7-4

MOOEL 169
SECTION 1. GENERAL INFORMATION
GENERAL INFORMATION
l-l. INTRODUCTION.
l-2. The Model 169 is a rugged, low cost, battery-
operated digital multimeter that provides full
measurement capability for many general purpose
applications. It provides dccurate readings from
IOOuVldigit to 1OOOV on five dc and five ac voltage
ranges, lOOnA/digit to 2000mA (2 amperes) on five dc
and five ac current ranges, and lOIlmn/digit to 20
megohms on six resistance ranges. Ranges and
~ccurxy are listed in the Table of Specifications
on page 1-3.
l-3. FEATURES.
l-4. The Model 169 incorporates features that help
prevent instrument damage through customer abuse and
provide maximum instrument reliability, operator
safety and simplicity of operation. Some of these
features are:
e A ZOOO-count (3-l/2 digit) liquid crystal dis-
play (LCD) with large 0.6" numerals, function
and range annunicators, and a low battery indi-
cator (BAT). Appropriate decimal point and
minus sign (-) are also displayed, positive
polarity is implied.
l The Model 169 is built rugged. The full bench-
sire cdse is molded from impact-resistant dnd
flame-retardant plastic. Effective input pro-
tection prevents damage on all functions.
Voltage ranges dre protected up to 1400V peak,
resistance ranges to 300VRMS and current ranges
dre protected by dn externally accessible 2A
(25OV) fuse.
0 Pushbutton switches dre color coded to the
front panel for quick and edsy selection of
function and range. The decimal point is duto-
matically positioned by the rdngc pushbutton.
Annunciators on the display Indicate the
selected function and range. Improper range
and function combinations are indicated by
contradicting function and/or range d""u"cid-
tars appearing dt the sdme time.
FIGURE l-l. Model 169. l-l

GENERAL INFORMATION MODEL
169
l
The latest LSI technology and stable precision
components have been used in the Model 169 to
provide long term accuracy and minimize main-
tenance. Only one calibration adjustment is
required, once a year. If alkaline batteries
are used, battery life can be the same as the
calibration cycle. Barring destructive misuse,
an MTRF of up to 20,000 hours can be expected.
l
Automatic zeroinq, automatic polarity and only
two input terminals simplify operation by
eliminating potentiometer zeroing and lead
changing.
l
Optional accessories can be ordered to extend
the measurement capability of your Model 169.
Some of these are:
High Voltage Probe allows your DMM to measure
from 1000V to 40kV dc.
High Frequency (RF) Probe allows your DMM to
measure from 0.25V to 30V rms ac over a fre-
quency range of IOOkHZ to IOOMHZ.
Clamp-On AC Current Probe allows your DMM to
measure from zero to 200A rms ac.
50.Ampere Current Shunt allows your IXIM to
neasure from zero to 50A. ac and dc.
NOTE
Refer to Section 4 for more detailed
information on accessories.
l-5.
WARRANTY INFORMATION.
l-6. The warranty is given on the inside front
cover of this Instruction Manual. If there is a
need to exercise the warranty, contact the Keithley
Representative in your area to determine the proper
action to be taken. Keithley maintains service
facilities in the United Kingdom and West Germany,
as well as in the United States. Check the inside
front cover of this manual for addresses.
l-l. CHANGE NOTICES.
l-8. Improvements or changes to the instrument
which occur after printing of the Instruction Manual
will be explained on a Change Notice sheet attached
to the inside back cover.
l-9.
SAFETY SYMBOLS.
l-10.
Safety symbols used in this manual we as
follows:
IMPORTANT
The A symbol can be found in various
places in this manual. Carefully read the
associated CAUTION statements with regard
to proper use and handling of the instru-
ment. Damage to the instrument may occur
if these precautions are ignored.
This symbol can be found in various
places in this manual. This svmbal indi-
cates those areas on the instrument which
are potential shock hazards. Carefully
read the associated WARNING statements
with regard to proper use and handling of
the instrument. Serious personal injury
w result if these precautions are
ignored.
l-11.
SPECIFICATIONS.
1-12. Detailed specifications for the Model 169 are
given in Table I-I.
1-2

MODEL 169 GENERAL INFORMATION
TABLE 1-1.
Specifications Mode
1169
MAXIM”M ALLOWABLE INPUT: 10”“” ims. ,400” prak.
,“*“.Hr. cO”ti”“o”S except 2”“m” range: 35”” m”,i”uuLkr. 15
sec. rndXirnUnlabove 35”“.
1-3

l-
BATTERY
ADJUSTMENT
RlO,
-__
FIGURE 2-1. Installation of Batteries.
NEGATIVE
DISPLAYED,
POSITIVE
IWLIED WHEN LW
MINUS l-1 CFF BATTERY MILLI (10-3) MICRO I 10-6)
AC DIPLAYEO, I
DC IWLIE" I
3-l/2 DIGITS
WITH DECIMAL
POINT
FIGURE 2-2. Model 169 Front Panel Display.
2-O

I
MODEL 169
SECTION 2. OPERATION
OPERATION
2-1. INTRODUCTION,
2-2. This section provides information needed for
incoming inspection, preparation for use and opera-
tion of the Model 169 and its accessories.
2-3. UNPACKING AN0 INSPECTION.
2-4. The Model 169 was carefully inspected, both
mechanically and electrically before shipment. Upon
receiving the Model 169, unpack all items from the
shipping container and check for any obvious damage
which (may have occured during transit. neport any
damages to the shipping agent. Retain and use the
original packaging materials if reshipment is re-
quired. The following items are shipped with all
Model 169 orders:
a. Model 169 DMM
b. six carbon zinc "C' cells (may be shipped
installed in the DMM in some units).
c.
d.
2-5.
2-6.
A copy of this Manual.
Separate optional accessories, as ordered.
PREPARATION FOK USE.
Installation of Batteries, if required.
3
WARNING
To prevent a shock hazard, all test leads
should be removed from the INPUT terminals
before removing the instrument top cover.
a. Turn the DMM bottom side-up and loosen the
four screws in the bottom cover until the threads
are not engaged. NOTE: The scrws are not retained
and they will fall out when the instrument is re-
turned to its normal position.
b. Hold the top and bottom ‘over together to
prevent their separation and turn the DMM cover to
normal position. Lift off the top cover.
NOTE
Carbon-zinc batteries are supplied. These
batteries will operate your DMM for ap-
proximately 1000 hours. If it is desired
to change batteries only once a year when
calibration is required, alkaline cells
may be substituted. These cells will pro-
vide approximately 2000 hours of opera-
tion. In either case, the low battery
indicator will automatically come on with
approximately 5% of battery life remaining
(20 hours for carbon-zinc and 40 hours for
alkaline cells).
t. Install the batteries in the holder ds shown
in Figure 2-1.
d. Press the battery clip onto the terminals of
the battery holder; then position battery holder on
the two spacers as illustrated.
e. Reinstall the top cover.
f. After the batteries are installed. you should
become familiar with the Model I69 by reading the
section titled Controls, Indicators and Connectors
(Paragraph Z-7); then perform the Initial Functional
Check (Paragraph Z-16).
2-7. CONTROLS, INDICATORS AND CONNECTORS.
2-B. Display.
2-9. The operating status of the Model 169 is con-
tinuously provided by the 3-l/2 digit (2000 count)
liquid crystal display located on the front panel.
In addition to the digitized input signal, with
appropriate decimal point and polarity, the display
provides indications of the selected function and
range, battery condition and overrange. All indica-
tors on the display are shown in Figure 2-2 and
described as follows.
2-1

OPERATION MODEL 169
a. Numerals. Large 0.6" numerals display up to a
maximum of 1999 counts. Leading zero is only sup-
pressed for most significant (l/Z) digit.
b. Decimal Point. The decimal point is indicated
in three positions and implied when behind the least
significant digit. The decimal point is properly
positioned when a range pushbutton is pressed.
C. Overrange. A "1" followed by three blanked
digits is displayed as an overrange indication for
all ranges and functions, except the 1000 volt
ranges which read beyond their maximum allowable
input voltages. The minus sign and a decimal point
may also be displayed, if appropriate.
d. Polarity. For dc measurements the minus sign
(-) is displayed, positive is implied. The minus
sign may flash on any function at zero since it is
not suppressed. It is also normal for it to flash
in ohms while the instrument is recovering from
overrange.
e. Low Battery Indication. BAT is displayed when
approximately 5% of battery life remains. This
indicates that the batteries should be replaced,
however the Model 169 will continue to operate pro-
perly for 40 hours if alkaline cells are installed,
or 20 hours if carbon-zinc cells are installed.
f. Function and Range Annunciators. These indi-
cators provide a continuous display of the selected
funCtiOn and range, and allow direct reading of the
display. For example: a displayed half-scale ac
current on the highest current range would read AC
IOOOmA.
NOTE
Extended exposure of the liquid crystal
display to direct sunlight, or high tem-
perature and high humidity conditions can
cause the display to temporarily blacken.
Also, the display may become sluggish if
exposed to extremely cold temperatures.
Even though recovery occurs at normal
Operating temperatures. these conditions
should be avoided for maximum display
life.
Z-10. Front Panel Switches.
Z-11. Control of the Model 169 is provided by
eleven pushbutton switches which are color coordi-
nated to the front panel. These switches are shown
in Figure 2-3 and described as follows.
a. ON/OFF Pushbutton. Push on - push off switch
that, when in, applies power to the DMM.
b. Function Pushbuttons. The four function push-
buttons provide selection of the five functions of
the Model 169. AC/DC is a push on - push off switch
that selects whether the function is ac or dc, in
for ac or out for dc. When ac is selected, the AC
annuncmtor is on. When the annunciator is off, dc
is implied. The AC/DC pushbutton is not effective
when ohms (0) is selected. The Y, A and " push-
buttons are push-on switches that select volts,
amperes and ohms, respectively. Pressing one of
these pushbuttons all the way in selects the new
function, turns on the proper annunciator and can-
cels the previously selected function. Note that it
is possible, by forcing, to push two pushbuttons in
at the same time. This will be evidenced by con-
flicting range/function annunciators appearing, and
the unwanted function can be canceled by pressing
the desired function pushbutton again.
c. Range Pushbuttons. The six range pushbuttons
are push-on switches which select the new range and
cancel the previous one. The decimal point is posi-
tioned and the appropriate annunciator is turned on
when the range is selected. The 20M pushbutton is
only used for ohms function. If it is inadvertently
selected with volts or current, contradicting annun-
ciators will appear.
2-12.
Input connections.
Z-13. Two banana jacks provide the input connec-
tions to the Model 169.
The HI (red) jack is the
high impedance input and is normally connected to
the point in the test circuit most removed from sig-
nal or earth ground. The LO (black) jack is the
common or low inout.
2-2

I
MODEL 169 OPERATION
TABLE 2-1
Initial Function Check
SELECTION DMM DISPLAY
STEP FUNCTION RANGE INPUT READING REMARKS
1
open 000 Power on, all other switches out. (-1 mdy flash.
2 ACV 200"V Shorted 00.0 ACmV
3 DC" 200mV Shorted 00.0 "V
4 A and n* 2k open .I00 mAkn Display reads 2mA current shunt on 2kn range.
Checks current fuse.
5 A and n*
200n and Open 1.00.0 ,,An
2mA Display reads 2mA current shunt on 200n range.
(approx. loon)
6 A and n* 2DOn and Open 1.0.0 uAfl Display reads 20mA current shunt on 200n range.
2olTd (100)
7 ” 2DM Shorted 0.00 M"
8 n 2DOOk Shorted 000 k"
9 " 20DOk Open 1 kn Overrange indication, leading 1 with all other
digits blanked.
*Press both pushbuttons simultaneously.
SET PWER Q4 @SELECT F"NCTI(N @SELECT @CONNECT IEZ302,A
RANGE SOJRCE
FIGURE 2-3. operating COntPOlS. z-3

OPERATION MODEL 169
t WARNING
To avoid electrical shock and/or instru-
ment damage, do not connect the LO input
to any source of more than 1400 volts
(peak) above earth ground.
2-14. Tilt Bail/Handle.
2-15. The 16 position tilt bail/handle allows you
to position the instrument for the best viewing
angle of the display.
2-16.
INITIAL FUNCTIONAL CHECK.
Z-17.
Now that the batteries are installed and you
have become familiar with your OMM, the initial
checkout procedure given in Table 2-1 should be per-
formed. This procedure provides d quick and easy
functional check of the DMM. Only test leads are
required. The check is designed to cause all annun-
ciators to appear, except for low battery (BAT).
All decimal point locations are checked. All digit
segments are checked, except for the horizontal cen-
ter segment on the last three digits. Since the
minus sign (-) is not suppressed on any function, it
should periodically flash on one or snore of the
funcrions at zero with the input shorted. By
selecting two functions and/or ranges in the test,
the current fuse is checked and d rough indication
of the condition of the respective current shunt and
range resistor is obtained. However, this test is
not intended to check the DMM accuracy, and thus,
the indicated readings in the table are nominal with
*5 digits allowed. If it is desired to check the
DMM accuracy specifications, perform the Performance
Verification, Section 3. The Initial Functional
Check is begun with power on and all other push-
buttons wt. To obtain this condition it may be
necessary to press unselected function and range
pushbuttons slightly to cancel previous selections.
After completing the functional check, operate the
Model 169 in accordance with the Operating Instruc-
tions beginning with Paragraph 2-18.
Z-18. OPERATING INSTRUCTIONS.
2-19.
The basic operating instructions for the
Model 169 DMM are outlined below. In addition,
there are individual instructions provided in this
section which describe how to nakt specific function
meas"rements. Refer to Figure 2-3 and operate the
DMM as follows.
A
CAUTION
Do not exceed the maximum input limits
given in Table 2-2.
a.
Turn on power by depressing the ON/OFF push-
button. If the instrument is within I&28“C, it is
useable immediately to rated accuracy. If the
ambient temperature is within 18-28°C range, but the
DMM has been subjected to temperature extremes, up
to I hour may be required to obtain rated accuracy.
b. Select the function with the AC/DC, V, A or n
pushbuttons.
c. Select the range by depressing the appropriate
range pushbutton.
d. Connect the source to the INPUT jacks and make
the medsupement. Accessories described in Section 4
should be used ds required.
TABLE 2-2
Sumnary of Maximum Inputs
MAXIMUM
INPUT
1OOOV DC, 1400V Peak AC
350V rms continuous, 15
sec. maximum above 350V
IOOOV rms, 1400 peak,
lO%.Hz
ZA, 250V DC or rms (fuse
protected)
-
2-4

I
MODEL 169
Z-20.
OC VOLTAGE MEASUREMENT.
Z-21.
The Model 169 reads dc voltage from 1OOpV/
digit to 1000 volts. The maximum displayed reading
is 1999 with appropriate decimal point. Polarity is
automatically sensed and the minus sign (-) will be
displayed, if applicable. Overrange is indicated by
a "1" and three blanked digits, except on the 1OOOV
range. On the 1OOOV range, the display can read
beyond the maximum allowable input voltage. Maximum
allowable input: 1OOOV dc, 1400 peak ac. Use the
Model 169 to measure dc voltage as follows:
OPERATION
A
CAUTION
A
CAUTION
00 not exceed the maximum allowable input
voltage. Instrument damage may occur.
a. Turn on power with the ON/OFF pushbutton;
select dc volts with the V and AC/DC pushbuttons.
The "V" annunciator should appear.
b. Select the range from the five ranges avail-
able. The decimal point is positioned by the range
pushbutton. The 'm' annunciator will appear if
2QOmV range is selected.
c. Connect the signal to be measured between the
INPUT HI and LO jacks; observe the voltage reading
on the display.
2-22.
AC VOLTAGE MEASUREMENT.
2-23. The Model 169 reads ac voltages from lOOuV/
digit to 1000 volts. The instrument is average
responding, calibrated to read the root mean square
value of a sine wave within a frequency of 45Hz to
5kHz. The maximum reading is 1999 with appropriate
decimal point. Overrange is indicated by a "1" fol-
lowed by three blanked digits, except on the IOOOV
range. On the 1OOOV range, the instrument can read
beyond the maximum allowable input voltage. Maximum
allowable input voltage:
1ooov Pm, 1400V peak,
106V.Hz maximum. Use the Model
169 to measure
ac voltage as follows.
00 not exceed the maximum allowable input
voltage. instrument damage may occur.
a.
Turn on power With the ON/OFF pushbutton;
select dc volts with the V and AC/DC pushbuttons.
b. Select the range from the five ranges avail-
able. The decimal point is positioned by the range
pushbuttons. The "rn' annunciator will appear if
200mV range selected.
C. Connect the signal to be measured between the
INPUT Hi and LO jacks; observe the voltaqe readin
on the display.
2-24.
AC OR DC CURRENT HEASUREIIENT.
2-25.
The Model 169 reads ac and dc currents from
lOOnA/digit to 2000 milliamperes (ZA). For ac mea-
surements the instrument is average rsponding, cali-
brated to read the root mean square value of d sine
wave of d frequency within 4%~ to 1kHz.
The maxi-
mum reading is 1999. with appropriate decimal point.
Overrange is indicated by d “1” followed by three
blanked digits. Input overload protection is pro-
vided by ZA, 250V dc or rms, quick-blow fuse. Use
the Model 169 to measure, ac or dc current as
follows.
A
CAUTION
00 not install .3 larger capacity current
fuse than the one originally supplied (ZA,
25OV). Instrument damage may occur'.
a.
Turn on power with the ON/OFF pushbutton.
Select ac or dc with the AC/DC pushbutton; depress A
pushbutton. The "A" annunciator should appear along
with the "AC" annunicator if dc was selected.
2-5

I
OPERATION MODEL 169
b. Select the range from the five ranges avail-
able. The decimal point is positioned by the range
pushbutton. The '11" annunciator will appear if
200uA range was selected; otherwise, the W annun-
ciator will appear. It should be noted that the
voltage drop across the current shunt in the instru-
ment (called voltage burden) can affect the circuit
under test if it has a low source voltage. This
voltage burden can be reduced by selecting the
highest current range that will resolve the desired
meas"rement.
C. Connect the signal to be measured to the INPUT
HI and LO jacks; observe the current reading on the
display.
2-26. RESISTANCE (n) MEASURENENl
2-27. The Model 169 reads resistance from 1OOnW
digit to 20 megohms. The maximum reading is 1999
with appropriate decimal point. Overrange is indi-
cated by a "1" followed by three blanked digits.
Maximum Allowable Input: 3OOV dc or rms. Use the
Model 169 to measure resistance as follows.
A
CAUTION
Turn the test circuit off and discharge
all capacitors before attempting in-
circuit measurements. A voltage may be
present in the circuit if either the minus
sign is displayed, along with a steady
displayed number other than zero, OP the
reading changes more than two digits when
the leads are reversed.
a. Turn on power and depress the 0 pushbutton.
The "n" annunciator should appear.
b. Connect the circuit to be measured to INPUT HI
and LO and select the desired range from the six
ranges available. The decimal point is positioned
by the range pushbutton and the applicable range
annunciator should appear.
c. Read the resistance an the display. If the
ZOOn range is selected, disconnect the test leads at
the test circuit, short them together and subtract
the reading obtained from the reading obtained
above.
NOTE
As previously mentioned far in-circuit
meas"rements, the presence of a voltage
will cause a change in the reading when
the leads are reversed. The presence of a
forward biased semiconductor junction will
also cause a significant error, and there-
fore, it is a good practice to reverse the
leads and make comparative measurements of
in-circuit resistances. In addition, it
should be noted that the bottom two re-
sistance ranges will not turn on most
semiconductors, except in an overrange
condition.
d. Diode Tests. Any of the top four ohms ranges
will turn on semiconductor junctions, with an
on-scale reading. but the 20Kn range is recommended
for out-of-circuit tests of semiconductors because
its test current is higher. To test a junction,
first forward bias it and then reverse bias it while
observing the display reading for both conditions.
The HI jack is positive. Compare the results as
follows:
INDICATION
1. Overrange. both Polarities
2. Low reading, both polarities
3. Overrange when reverse biased
and an on-range reading when
forward biased
JUNCTION
CONDITION
OPEN
SHORTEO
PROBABLY
GOOD
2-6

MODEL 169 PERFORMANCE VERIFICATION
SECTION 3. PERFORMANCEVERIFICATION
3-l. GENERAL. 3-3. RECDHMENOEOTEST EQUIPMENT.
3-2. Performance verification inay be performed upon
receipt of the instrument to ensure that no damage
or misadjustment has occured during transit. Veri-
fication may also be performed whenever there is
question of the instrument's accuracy, and following
calibration, if desired.
3-4. Recommended test equipment for perfornance
verification (and calibration) is listed in Table
3-l. Alternate test equipment may be used. HOW-
ever, if the accuracy of the alternate test equip-
ment is not at least 10 times better than the
instrument specifications, additional allowance must
bc made in the readings obtained.
NOTE 3-5. ENVIRONMENTAL CONDITIONS.
For instruments that are still under war-
ranty (less than 12 months since date of
shipment), contact your Keithley repre-
sentative or the factory immediately if
the instrument falls outside of specifica-
tions as determined by the Performance
Verification Procedure in paragraph 3-7.
3-6. All measurements should be made at an ambient
temperature within the range of la0 to 28OC (65" to
BZ'F), and a relative humidity of less than 80%.
3-7. PERFORWNCE VERIFICATION PROCEDURE.
3-B. Use the following procedures to verify the
basic accuracy of the Model 169 for vo:tage,
resistance and current measurements.
TABLE 3-l
Reformended Test Equipment for Performance Verification.
ITEM
-
A
B
C
0
E
DESCRIPTION
DC Calibrator
AC Calibrator
AC Calibrator/Amplifier
Decade Resistor
Current Calibrator
SPECIFICATIONS
O.lV, lV, lOV, IOOV
1ooov , to .005%
O.l”, 1”. lo”, 1oov
*0.0223
1000" 20.04%
1.9k", 19kn, 190kn,
1.9Hfl, lOMn,
?0.02%
lOOpA, lmA, lOmA.
IOOmA, 1A. to.034
IMFR.
Fluke
H-P
H-P
ES1
Valhalla
MODEL
341A
745A
745R/746A
0862
2500
3-l

I
PERFORMANCE VERIFICATION MODEL 169
NOTE
Performance verification should be per-
formed by qualified personnel using
accurate and reliable test equipment.
TABLE 3-2
DC voltage Perfornance Check
3-9. Initial Conditions.
3-10. Before beginning the verification procedure
the instrument must !meet the following conditions:
a. If the instrument has been subjected to
extremes of temperature, allow internal temperature
to stabilize for one (1) hour minimum at the
environmental conditions specified in paragraph 3-5.
b. Turn the instrument on and check for low
battery indication. If low battery indicator (BAT)
is on, remove and replace the batteries with fresh
O”L?S.
t
WARNING
Some procedures require the use of high
voltage. Take care to prevent contact
with live circuits which could cause
electrical shock resulting in injury or
death.
3-11. DC Volts Checkout.
a. Select dc voltage readings with the AC/DC and
V pushbuttons.
b. Connect the DC Calibrator (Item A, Table 3.1)
to the instrument.
c. Select the 200mV range, and apply positive
1OOmVdc to the OMM. The reading must be within the
limits specified in Table 3-2.
d. Select each remaining range and apply the
required voltage as specified in Table 3-2, verify
that the reading is within specifications.
e. Repeat all checks with negative voltage.
Range
ZOOmV
2v
20 v
200 v
1000 v
Applied
Voltage
100.00 mv
1.0000 v
10.000 v
100.00 v
1000.0 v
Allowable Reading at
180 to 2rc
99.6 to 100.4
.996 to 1.004
9.96 to 10.04
99.6 to 100.4
996 to 1004
3-12. AC Volts Checkout.
a. Select ac voltage readings with the AC/DC and
V pushbuttons.
b. Connect the AC Calibrator (Item B, Table 3-1)
to the OMM. Set the calibrator frequency to
1kHz.
c. Set the DMM to the 200 mV range and apply 100
mV ac to the OMM. The reading must be within the
limits specified in Table 3-3.
d. Select the 2, 20 and 200 volt ranges and apply
the required voltages as specified in Table 3-3.
Verify that the readings are within specifications.
e. To check the
1000 volt range, connect the AC
Calibrator Amplifier (Item C, Table 3-l) to the
output of 1000 volts ac rms and verify that the OMM
reading is within the specified limits.
TABLE 3-3
AC Voltage Performance Check
Range
200mV
2v
20 v
200 v
1000 v
Applied
Voltage
100.00 mv
1.0000 v
10.000 v
100.00 v
1000.0 v
Allowable Reading at
18’ to 28’C
98.7 to 101.3 mV
.987 to 1.013 V
9.87 to 10.13 V
98.7 to 101.5 V
987 to 1013 V
3-2

I
MODEL 169 PERFORMANCE VERIFICATION
3-13. Resistance Checkout.
a. Select resistance readings by pressing the n
pushbutton.
b. Select the 2000 range.
C. Connect the decade resistor (Item 0, Table
3-1) to the OMM.
d. Set the decade resistor to zero and measure
the resistance of the test leads. Subtract this
reading from the display in all of the following
steps.
e. Set the decade resistance to
190.0.
Verify
that the reading is within the limits specified in
Table 3-4.
f. Continue the resistance check by selecting the
next range and measuring the next resistance as
specified in Table 3-4. Verify that the reading is
within specifications. Test each item in the table.
TABLE 3-4
Resistance Perfonance Check
Ran e Resistance
r--t--
200 n 190.0 ”
2 kn 1.9OOkn
Allowable Reading at
18’ to 28’C
189.1 to 190.9 n
1.695 to 1.905 KZI
20 kn 19.0Okn 18.95 to 19.05
Kn
200 kn 190 .Okn
189.5 to 190.5 Kn
1895 to 1905 Kn
9.19 to 10.21 Mn
I
3-14. DC Current Checkout.
a. Select dc current readings with the AC/DC and
A pushbuttons.
b. Connect the dc current source (Item E. Table
3-1) to the DMM.
C.
Select the 200uA range and apply a current of
lOO.OOpA to the OHM. The reading must be within the
limits in Table 3-5.
d. Select each range and apply the required cuv-
rent as specified in Table 3-5. Verify that the
reading is within specifications.
3-15. ANALYSIS.
3-16. If the instiwwnt is out of the specified
limits given in Tables 3-2 through 3-5. either
troubleshooting and repair or calibration, a5
described in Section 6, may be required. NO~Il~lly,
recalibration will only be the indicated solution
when the instrument is out of speciflcbtlon on ~lofe
than one function (except for the higher ranges of
DC volts which are tht most critical). If the
instrument is still under warranty, refer to the
Note in Paragraph 3-2.
TABLE 3-5
DC Current Performance Check
Applied Allowable Reading at
Range current 18' to 28°C
200 PA
100.00 "A 99.1 to 100.9 uA
2 nA 1.OOOO mA .991 to 1.009 mA
20 mA
10.000 mA 9.91 to 10.09 mA
200 mA 100.00 mA 99.1 to 100.9 mA
1000 mA 1000.0 mA 991 to 1009 mA
3-3

MODEL 169
SECTION 4. ACCESSORIES
ACCESSORIES
4-l. GENERAL.
4-2.
This section describes the various accessories
and options available for use with the Model 169
OMM.
4-3. MODEL 1600 HIGH VOLTAGE PROBE.
4-4. The Model 1600 High Voltage Probe (shown in
Figure 4-l) extends the measurable dc voltage range
up to 40 kilovolts. It has a 1OOO:l division ratio,
so that a reading of 1 volt on the DMM corresponds
to 1 kilovolt (1000 volts). To "se the probe,
select DCV and the required range, connect the high
voltage probe banana plug to the instrument, connect
the alligator clip to soui-ce low, and touch the
probe tip to source high.
t WARNING
Be sure the alligator clip is connected to
source low before touching probe tip to
souw? high. A shock hazard or damage to
instrument may result.
Specifications
Voltage Range: 0 to 40,000 volts DC.
input Resistance: 1000 megohms.
Division Ratio: 1OOO:l.
Ratio Accuracy:
t1.5% at 25kV, decreasing to
Q.O% at 20k" and 30k",
e3.04 at 1OkV and 40kV, and
t4.0% at IkV.
Ratio Stability: ?O.Ol% per Y; *0.1x per year.
Heating Effects: Self-heating due to application
of high voltage for period in excess of 1 minute
will cause a maximum of 0.2% additional error at
40kV (error is less at lower voltage).
4-5.
MODEL 1651 50-AMPERE SHUNT
4-6.
The Model 1651 50-Ampere Shunt (shown in
Figure 4-2) permits current measurements of up to 50
amperes ac or dc. The shunt has a resistance of
0.001 ohm ?l%, so that a 50-ampere current vill car-
respond to a reading of 50 millivolts (0.0500 volt).
Set the "NM to ACV or DCV and select the required
rangc. TO use the shunt, connect the leads fur-
nished with the shunt from the shunt screw terminals
to the OMM input terminals. Use separate leads (not
furnished) to connect the source to the hex head
bolts. Be sure to use leads with a capacity of 50
amperes, or as needed.
4-7.
MODEL 1681 CLIP-ON TEST LEAD SET
4-8. This set (shown in Figure 4-3) contains two
leads with banana plugs at one end and spring-action
clip-on probes at the other end. TO use, insert the
banana plugs into the "NM and attach the prober to
the source.
4-9. MODEL 1682 RF PROBE
4-10. The Model 1682 RF Probe (shown in Figure 4-1)
permits measurement of dc voltages dt frequencies of
20 kilohertz to 100 megahertz. Connect the probe to
the input terminals and select 3CV and the appro-
priate range.
Specifications
Voltage Range: 0.25 to 30 volts nns.
Transfer Accuracy: i0.5dS. 1OflkHr to 10OWr peak
responding calibrated in rms of d sinewave.
Input Impedance: 4 megohm shunted by 3pF.
Maximum Allowable input: 30V rms AC, ZOOV DC.
Accessories Supplied: straight-tip, hook tip,
ground clip, hi adapter, banan; plug adapter.
4-1