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INSTRUCTION MANUAL
MODELS 164,164TT
DIGITAL MULTIMETER
KEITHLEY INSTRUMENTS. I N C.
CONTENTS
PRmTED OCT. 74
164. 164l-T
ILLUSTRATIONS
Figure Ii". Title Page NO.
1 Front Panel 1
2 Front Panel Controls b Terminals, Model 164 3
3 Rear Panel Controls b Terminals, Model 164 3
4 Four-Terminal Resistance Measurements 8
5 Timing Diagram for AID COnVerfer 12
6 Typical Open-Collector outpue 13
7 Pill Designations For Printer output 13
8 Front & Rear Panels, Model 164TT 14
9 Multimeter Block Diagram 15
10 Analog Amplifier Block Diagram 16
11 A/D Converter Block Diagram 18
12 Integrator Simplified Diagram 19
13 RANGE Knob Assembly 25
14 Chassis Assembly 25
15 servicing Of Chassis 26
16 PC Board I.ocacions 27
17 Side View of Chagsis 28
18 Chassis, Bottom View 31
19 Calibration Controls 32
20 Calibration of Milliohm Current Source 34
21 Top Cover Assembly 37
22 Botfom cover Assembly 37
23 Component Layout, PC-254 50
24 Component Layout. PC-251 51
25 Component Layout, PC-248 51
26 cmlponent Layout, PC-255 52
27 Camponene Laywf, PC-250 52
28 Component Layout, PC-287 53
29 componenr Layout, PC-348 54
SPECIFICATIONS MODELS 164, 164TT
SPECIFICATIONS
I
0)
iv 0474
Sheet I of I
1275
KEITHLEY INSTRUMENTS. INC
CAUTION
To ensure the integrity of the chassis to earth ground connection only a Keithley
part number CO-7 line cord should be used for replacement. If a different line cord
is used ensure that the wiring polarity is the same as shown in the following dia-
gram.
NEMA
5-l5P
WHiTE WHiTE
Keithley Models to which this warning applies: 160, 163, 164, 165, 171, 180, 190, 227,
616, 6162, 702, 780
MODELS 164, 164TT GENERAL 1NFORMATION
SECTION 1. GENERAL INFORMATION
l-l. GENERAL. e. AC/DC Probe Accessory. The Model 1601 AC/DC
Probe permits ac voltage meas"reme"ts to 250 volts
a. mm Mode. The Model 164 serves as a line aper- rms over a spa" of 45 Hz Co 45kHr. A probe mounted
ated 3-l/2 digit multimeter having wide ranges for switch enables selection of ac or dc operation vich-
measllrement of voltage, currerlt, and resiseance. I" out disconnecting the probe.
the D"M mode. the 164 offers seven dc volrage ranges
(from 1 microvolt per digit to 1000 volts). eight dc
current ranges (from 0.1 nanoampere per digif to 2
amperes), and eight resistance ranges (from 0.1 ohm
per digit LO 2000 megohms). 1-2. APPLICATIONS. The Model 164 is a general pur-
pose instrument - used Fn Basic Research, Electronics
b. Milliobmmerer-Obmeter Mode. The Model 164 Development. and Process Control.
also Provides five additional resistance ra"ze8 for
mas";eme"fa requiring resolution to 10 microbm per a. I" the Research Lab - When used vith a suitable
digit. Four-terminal measurement technique minimizes probe, transducer, or electronic circuit, Model 164
the effects of lead and contact resistance in 1orre- can be used for digital indication of volts. amps.
sistance measurements. or ohms. or through conversion, any physical para-
meter such aa temperature, pressure, and rpm.
C. Electronic High/Low Limit Trip option. The
Model 164TT provides independent electronic trip b. I" Electronics oevelopmene Acriviry - "seable
CirCUitS for high and low limits. me trips are for basic electrical m?as"reme"ta of voltage. cur-
"on-latching. I" addftio" to front pane1 indiG- rent. or resistance.
to= lamps, the Model 164TT offers rear panel r-e-
lay contacts.
d. Di.sital Oue~ut Accessory. The Model 1602 is a
field-installable BCD output which my be used to inter-
face the Model 164 wit31 a digital printer or computer.
@
0474 1
GENERAL INFOFwAT1ON MODELS 164. 164~~
TABLE l-1.
l+O"f Panel Controls and Terminals
i
Control Paragraph
RANGE SWITCH Sets the full range seneiei"ity and parameter to be measured (volts, 2-2b
amperes, or ohms in the D"N made, or milliohms/obms in the Milliobm-
meter made).
In", " Providea S.z"t?" voltage ranges from 1 mflli"olL full range to 1000 "OltS
full range.
"A, IIA. mA Provides eight current ranges from 100 nanoampere full range to 1000
milliamperes full range.
n, krl, MO Provides eight resistance ranges from 100 ohms full range to 1000 meg-
ohms full range.
2-b
Power Controls ac line power to insfrument
DMM Sets instrument for DMMmode of operation
mn,n sets instrumenf for any one of five resistance ranges from 10 miniohm
full range to 100 ohms full range. (Milliobm current source terminals
m"st be connected to ""know".)
SOURCE SWITCH 2-k
operate sets instrument for normal millioblmneter operation (non-voltage limit
made).
Volt Limit Sefs instrument for "elf-limit operation such that maximum open-circuit 2-9e
voltage is limited to 20 millivolts. In this mode, measurement accuracy
is degraded depending on the resistance to be measured. see X-9.2.
Sets instrument for compensating thermal emfs in the milliobmmeter
mode. (Used in conjunction with the Zer" control.)
I: ZERO CONTROL
nn SO"RCE TERMINALS
Red
Permits adjustment of display zero. 2-2d
*-la
Black currene source low (negative polarity)
I! Z-la
Red Input high
Black Input law
Case ground
TABLE l-2.
Rear Panel Controls and Terminals
I
Control Functional Description Paragraph
Line Switch Sets instrument for either 117 or 234 volt lina power. 2-3a
(117-234V)
AC Power Receptacle Mates with 3-"tie ac line cord. 2-4b
1 zero Control screwdriver adjusrmenr for zeroing o* 1 mv 2-3b
output Recepracle Analog Output. (r 1 volt dc at full range at up to 1 milliampere). 2-12
BCD output Receptacle Optional BCD output available with Model 1602 Digital Output Kit. 2-14 I
2 0774
MODELS 164, 164TT GENERAL mFOF.MATlON
Jl203
MILL1 RANGE
SOU SWITCH
SlOl
d204
HI LO CASE SOURCE ZERO MODE/POWER
JlOl J102 5104 SWITCH CONTROL SWITCH 51201
s1202 R1215
OMM INPUT
FIGURE 2. FronL Panel Controls h Terminals, Model 164.
LINE
ZERO SWITCH
CONTROL s202
R505
AC POWER
RECEPTACLE
OUTPUT
5201
RECEPTACLE
5103
I FIGURE 3. Rear Panel Controls b Terminals. Model 164.
0414 3
SECTION 2. OPERATING INSTRUCTIONS
1-l. 1NPUT CONNECTIONS. NOTE
a. "inding Pose Terminals. The inscrumen~ provides attenuation of line
frequency noise superimposed on an input
L. DMMMode. Uinding post terminals are pro- signal. The a-c rejection is specified as
vided o" the front panel for connections EO input f0110!.W:
HI (Red), input LO (Black), and chassis ground
(ccee"). For voltmeter, ameter, and ohmmeter WXR: Greater rha" 80 dB above one digit
measurements, the source should be conneceed be- for a voltage of line frequency or rwice
tween the lower set of red and black termi"als. line frequency an the nw5t sensitive range?.
Tile green rennin=1 may be connected to input LO decreasing to 60 dB on the 100-millivolt
by use of a shorting link when grounded operation and higher ranges. 1000 volts peak-to-peak
is desired. see paragraph 2-11 for a discussion mCXXim"m.
Of fl"aZi"g operation. CMRR: Greater than 120 dB above one digit
at dc and 40 to 100 Hz ac. 500 volts dc,
`. Xilliobmecer Mode. A separate pair of red 100 volts peak-to-peak ac maximum
and black terminals is provided for use when making
four-rermina1 reSiSLa"ce nleaeurements. The rnilli- Proper shielding as described in paragraph 2-1,~
ohm ct~rrent source provides a positive dc current can minimize noise pick-up when rhe insrrumenc is
at ihe iHI (Red) terminal and is used in conjuncrio" in the presence of excessive a-c Eiclds or when very
wietl ci,e DMM terminals. See paragraph 2-9 for a sensitive measurements are being made.
discussion of milliohmeeer operation. The Model
1641 Kelvin Test Lead Set (furnished with the Model 3. Magnetic Fields. `The presence Of strong mag-
L64) simplifies connections co the resistance to be "etic fields can be a potential source of a--c noise.
measured. The Test Lead provides clip-o" connec- Magnetic flux lines which cut a conductor can pro-
tions for both voltage and current leads without duce large a-c noise especially at power line fre-
the need for separate cables. quencies. The voltage induced due t" magnetic flux
is proportional to the area enclosed by the circuit
b. Noise Considerations. The limit of resolution as well as the race of change of maflnetic flux. 2%"
in voltage and current measurements is derermined effective wag co minimize magnetic pickup is LO ,'
largely hy rhe noise generated in the source. Stray =rra"ge all wiring SO Chaf fhe loop area enclosed
low-level noise is present in some form in nearly al1 is as small as possible (such as twisting input leads).
electrical circuits. The instrument does not distin- h Second way t" minimize mnR"etic pickup is to use
guish between stray and signal voltages since it mea- shielding as described in paragraph 2-1,~.
sures the net voltage. When using the 1 mV and 10 mV
ranges, consider the presence of low-level elecrrical
phenomena such a~ thermocouples (thermoelectric ef-
fect,, flexing of coaxial cables (triboelectric ef-
fect), apparent residual charges on capacitors (die- C. Shielding.
lectric absorption,, and battery actFan of two dFf-
ferenr contact materials (galvanic action). 1. Electric Fields. Shielding is usually "eces-
say, when the instrument is in the presence of very
1. Thermal Ems. Thermal `auf.9 (thermoelectric large a-c fields or when very sensitive measureme"ts
porentiale) are generated by thermal differences are being made. The shields of the measurement cir-
between two junctions of dissimilar metals. To cuit and leads should be connected together t" ground
minimize ehe drift caused by thermal emfs, use cop- at only one point. This provides a "tree" config-
per leads to connect ehe circuit to the i"s~rume"t. uration, which minimizes ground loops.
The front or rear panel ZERO control cm, be used
to buck out thermal offsets if aecessary. 2. Magnetic Fields. Magnetic shielding is use-
The KeiChley accessory Model 1483 Low Thermal Con- ful where very large magnetic fields are present.
nection Kit confains a11 necessary materials for Shielding. which is available in the form of plates,
making very low thermal cop,xr crimp connections foil or cables, ca" be used to shield the measuring
for minimizing thermal effecrs. circuit, the lead wires, or the instrument itself.
2. A-C Electric Fields. The presence of elec- 3. other Considerations.
tric fields generaced by power lines or other
s""rceB can have an effect on instrument operation. a) Voltmeter Measurements. "se shielded in-
A-C voltages which are very large with respect to put leads when so"rcr resistances are greater
the full-scale range sensieivicy could drive the than lmegohm or when long input cables are used.
a-c amplifier into saturafian, thus producing a"
err""e""s d-c oq.tpue.
4 0414
MODELS 164, 164TT
b) current Measurements. on the InA CUrrent 3. Zero Posltia". This position disconnects the
ranges, no special shielding precautions need be current source from the ""k"0w" for zeroing the
taken. "rawever, on the UA and nA ranges, shield- Model 164 in the milliohmeter mode only.
ed input leads are recormended.
d. Zero Conerol. This conrro1 is uSed in co"-
,unction with the Source Switch (Zero Position) to
put leads and =o"rce are recommended for m==="r=- zero the reading in the milliohmeter mode. The co"-
menes an the 10 megohm through 1000 megoh ranges rral may also br used in the DMMmode for adJustme"ts
on the 1 mV and 10 m" ranges. (A rear panel zero
adjusrmenr ie also provided for making co==== zero
=d,ustme"fs.) Place a short =cro== "oltm=t=r t=r-
minals before ad,usfi"g zero in Voltmeter mode.
2-2. FRONT PANEL CONTROLS.
a. Power/Mode Switch. This switch permits selec-
tion of onerafine mode. The DMM oosirio" allows the
Model 164 co be used as a voltme&, ameter, and
ohmmeter. The mn and n positions allow the Model 164
to be used as a four-terminal resistance measuring
instrument. The Power OFF pcxition disconnects line
power to the instrument.
b. Range Switch. This switch permits selection
Of function and full range in the mm mode.
2. "oltage Funcrio". The voltage sectors of the
Range Switch are designated in millivolts (mV) and
Volts (") for full ranges from 1 millivolt to 1000
Volts. A full stop at the 1000 Volt range prevents
inad"erranL Switching to the nanaampere ranges with
clockwise switch rOCatlo*.
3. Resistance Function. The resisrance (ohms)
sectors of the Range Switch are designated in ohms
(n), kilohms (K!?), and Megohms for full ranges
from 10" ohms to 1000 megohms.
4. Current Function. The current (amperes) s=c-
fors of the Range Switch are designated in "a""-
amperes (*), microamperes (NY), and milliamperes
(ma), for full ranges from 100 nanoamperes fO 1000
milliamperes.
C. Source Switch. This switch permits selection
of operate, Volt Limit, or zero operation when using
rhe mR, n modes.
For maximum operaeor safety, connect the ground wire
1. operate Position. This position permits *or- of the line cord LO earth ground. This will ensure
ma1 operation of the Model 164 as a four-terminal that the CASE is at graund potential.
resistance measuring instrument.
2. Volt Limit Position. This position limits the
ope"-circ"it voltage of the mi11*otlm current source
to 20 millivolts. ln this mode, measurement =CCU-
racy is degraded depending 0" the resi=t="C= to be
measured. POT example, if a full range resistance d. Funcfion,Ra"~e Selection. sehxr the PU"Cti0"
is connected (such as 10 0" the 1Q Range) the I"===- and Sensitivity using the RANGE switch. I" MILLI-
urement accuracy is degraded by 5% since a 2On re- OHMMETER mode, the RANGE switch is used in co"ju"c-
sistance is shunting the input. tion with the MODE Svirch as described in paragraph
2-9.
0774 5
---.-____I
I "PERKrING
INSTRUCTIONS HODELS 164, 164~
2-5. MODESOF OPERATION. The Model 164 permits meas- d. Innut resistance. The input haa a reeist="Ce
urements in either of two modes of operation, 1, Multf- "f 10 m=whms 0" the 10 millivolt and higher =a"~*,
meter ?lode (DMM) or 2) Ohmmeter-Milliobmmeter Mode (n, 1 megohm on the l-millivolt range. FO= lomv and
mn). higher =a"Ses, a 1000 ohm source eestatance will
introduce only 0.01% e==o=. 'ro maintain rated acw-i
a. Elulrimeter Mode (DMM . I" the DMMmode, rbe
1 racy o" the 1mV =a"~. the source reaiseance should
Model lb4 permifs measurement of uolrage, current, not exceed 100 ohms.
and resiseance (LO 0.U per digit) for conventional
cAeas*relne*ts. To select the DMN mode, set the Mode e. Off-Ground Measurements. The instrument low
Switch to the DMMposition. men set rhe Range terminal can be floated *500 volts above CASE ground
Switch to the appropriate function and range. for voltage ,~~~%S"re?me"t~. Refer to paragraph 2-11
for complete instructions.
b. Ohmmeter-Milliohmmeter Mode (0, mi2). I" either
thz1 or mil modes, the Model 164 permits mea~"=ement f. AC Voltage Adapter Probe. The Model 1601 AC/DC
Of resistance using a four-terminal voltage-current Probe permits convenient a-c voltage meaguremenfs from
method. To select the n or mii modes, set the Mode 0.1 volt to 250 volts rms o"e= a span of 4s HZ to 45
Smirch to the desired "ohms" position. Separate kkh. A probe-mounted switch provides convenient se-
rerminals ace provided for cu==ent and voltage se"- lection of,a-c o= d-c operation without disconnecring
sing. rhe Model 1641 Kelvin Test Lead Set ifurnish- the probe. Therefore, the probe may be pe=manently
ed with the Model 164) simplifies connections to the attached.
resiSta"ce to be measured. The terminals identified
as "m;2 SOURCE" provide a c"==ent in five decades 2-7. aMMETER OPERATION (DMM Mode). This mode of
from 10 microamperes to 100 milliamperes, co==eg- operation enables current meaS"=eme*ts from 0.1 "ano-
pending to positions on the Made Switch identi- ampere per digit (100 nanoamperes full range) to 2
fied as IOK?, IOn, I!,, 100m0, o= 10mrt. The ter- amperes with 100% overranging on all ranges.
minals normally used for "MB measurements are for
voltage sensing when making four terminal resis- a. Range Selection. To select ammeter operarion,
tance meusurements. The Range Switch Of the Model set the Mode Switch to DMM, the" set the RanSe Switch
164 nl"Sf he set to rile lrn" function when using the to the appropriate full range cu==e"t. As an ammeter,
oirmmeter-milliohmmeter modes. the Model 164 provides eight ranges as given in Table
2-2.
2-6. VOLTMETEROPERATION @MM Node). This mode of b. Co""ecfio*s. Connect the input twminals so as
operation enables voltage meaS"=eme"eS from il micro- to place the Multimeter in series with the current to
volt per digit (1 millivolt full range) to tlOO0 volts. be measured.
Range Selection. To select "oltmeLe= operation C. Measurement Accuracy. The current accuracy is (?
se:'the !Iode Switch t" DMM, then set the Range Switch specified as '0.2% of reading, fl digit on all ranges:
to the appropriate full range voltage. as a "olr- Since the accuracy is specified ac the input terminals,
meter, the Model 164 provides seven ranges as given the loading effects should also be considered. See
in Table 2-l. Table 2-2 for values of shu"t resisfors.
TABLE z-1. d. Off-Ground Measurements. The Model 164 low
"olmeter operation terminal can be floated t500 volts above CASE ground
for current measu=eme"ts. Refer to paragraph 2-11
Range setcin Full P.a"Se Display Overrange Display for complete instructions.
I El I
1 In" 1.000 In" 1.999 In" 2-S. OWMMETER OPERATION @MM Mode). TXhis mode of
10 In" 10.00 rn" 19.99 rn" operaeion enables resistance meaS"=eme"eS from 0.1
100 II" 100.0 mv 199.9 in" ohm per digit (100 ohms full range) to 2000 megohms.
1 " 1.000 " 1.999 "
10 v 10.00 v 19.99 " 2,. Range Selection. TO select ollmmeter operation
100 " 100.0 v 199.9 " @MM mode), set the Mode Switch to DMM, then set the
1000 " 1000. " 1000. v* Range Switch to the appropriate full range resistance.
As an ohmmeter, the Model 164 provides eighr ranges
*Maximum allowable input is 1000 volts continuous in- as given in Table 2-3.
p"t on 1-"OlC to 1000~volt ranges. 1000 volts momen-
tary, 300 volts co"rin"ous on lower ranges. b. Voltage Across the Unknown. "olfage drop is
100 millivolts at full range with 1.5 V max. into
b. Measurement Accuracy. The voltage a~curac,. is a" open circuit. Thus the current through the "n-
t(O.l% of reading + 1 digit) on all ranges. known is determined by dividing the 100 millivolts
by the full range resistance.
C. Overload Recovery. The instrument will recover c. Maximum Overload. Maximum voltage ac=oss the
from 300-volt overloads within five seconds on the input tennina1s is 20 voles momentary and 1 Volt
lm" range. "p CO 1000 volts peak may be applied co"ti""o"s.
momentarily on any range without damaging the i"st=u-
ment . d. Accuracy. As shown in Table 2-4.
6 0474
1 UA 1.000 LlA
10 II.4 10.00 pA
100 "A 100.0 DA
ImA 1.000 mA
10 m.4 10.00 mA 19.99 mA 1 0
100 m.4 100.0 mA 199.9 InA 0.1 a
1000 mA 1000. m.4 1999. m.4 0.1 1
TABLE 2-3.
ohmmeter operation
Range setting Full Range Display overrange Display Impressed current
100 n 100.0 n 199.9 n ImA
1 !4 1.000 !4 1.999 kl2 0.1 mA
10 !4 10.00 kn 19.99 I& 0.01 mA
100 kn 100.0 kn 199.9 kli 1 "A
1 MST 1.000 MCI 1.999 MO 0.1 )A
10 Mn 10.00 MO 19.99 km 0.01 U.4
100 MO 100.0 Mn 199.9 Mn 1 "A
1000 Mn 1000. Mrl 1999. Mn 0.1 n.4
i
Full Scale RanRe Accuracy of Reading*
100 n to.32 k 0.1 :i
1 km 20.3%
10.3%
$0.3%
.xXx
x.xX
xX.x
xxx.
!O
0474
.-
OPEP`4TING 1NSTR"CTIONS MODELS 164, 164'~
z-9. OHMMETER-MILLIOIIMMETCROPERATION ($2, "!i Mode). the displayed reading tlust be interpreted by calcula-
I" the :r,mr moties, the Model 164 permits meaS"reme"t ting Ohm's law where R = V/r. we,, using the 1 m"
Of resisrance from lOUS per digit to 2oon "Sing a RP"c- setting, no calculation is necessary since the
four-cermina1 voltage-current method. Model 164 provides direct-reading ranges as marked
on the Mode SWiTCh. If any other "Oltage range is
d summary of operation. used (other than 1 rn") the resistance must be deter-
mined by calculation since all decimal points will r),
1. cannect OMMand ml2 source terminals to resis- be lighted (therefore the decimal p~int location will
tance LO be measured. be ambiguous). The direct-reading ranges available
on the Model 164 are shovn in gable 2-s.
2. set RANGE ta h"
d. Current Source. The current source in the
3. set ?foLte Switch to desired range: l"lDil, Node1 164 provides a constant current which may be
lOOmA, I::, 102, or 1000. selected in five decade steps from 10 microamperes
to 100 milliamperes. The source can provide a corn-
4. set source Switch to ZERO. plia*ce "oltage up to 2 volts (in OPERATE mode only)
on au mnin mode settings. For example, the Model
5. Adjust Zero Control for zero display. 164 may be used co furnish a currenf of 100 milli-
amperes to a load resisrance of.20 ohms (giving a 2
6. Set Source Switch tc, OPERATE (except for "OLT- volt drop). I" the "OPERATE" mode, the Model 164
LIMIT operation). Refer to section 2s9e for "OlC has an open-circuit voltage of approximately 15 volts
Limit Operation. In the "VOLT LIMIT" mode, the Model 164 has an onen
circuit voltage of 20 millivolts.
b. cannectians. separate pairs of rermina1s are
provided for rile current source and voltmeter to fa-
CiliCaLe four-terminal resistance measurements. me NOTE
rermina1s identified as "n& SOURCE" provide a current
which may be selected in five decade steps from 10 If the resistance LO be measured is polarity
microamperes to 100 milliamperes. me terminals nor- sensitive, the" care should be take" to con-
mally used for mm meaSureme"tS (lower pair) are the nect the red (positive) terminal to the un-
"oltmeter terminals. known so chat the desired polarity is obtain-
ed. (Conventional current flow is out Of the
red terminal and into the black terminal.)
c. Range Selection. I" the mn,n mode, the current
supplied at the "Inn SOURCE" terminals (upper pair)
may be selected in five decade steps from 10 micro-
amperes co 100 milliamperes. when the Range switch
is ser to 1 In" sensitivity, the" the five positions
on ciie Mode svitch correspond to full ranges of 1cmn,
lOOna, 1.2, 1052, or 10057. since the full range resis-
tance is determined by the current impressed at the
"l"G SO"RCE" terminals and the voltage sensitivity,
r
MODEL 164
VOLTAGE LEADS Vl,VZ
CURRENTLEADS Cl, C2
RESISTANCE UNDER TEST
FIGURE 4. Four-Terminal Resistance Measurements
8
MODELS 164, 164TT OPERATING INSTRUCTIONS
TABLE 2-5.
Full Ranges in mn and il Modes
Max. Reading
Mode setting hange Setting* (wirh 100% overranping) mu source
0
10 roil 1 m"* 19.99 mn 100 mA
100 mil 1 Ill"* 199.9 mn 10 ULA
1 n 1 In"* 1.999 !! lti
10 !I 1 mv* 19.99 .i 0.1 mA
100 11 1 In"* 199.9 '2 0.01 ti
*decimal location is valid only when lm" range is selected.
e. Voltage Limit Operation. The VOLT LIMIT mode f. Power Dissipation in Unknown. The power dis-
limits rhe own-circuit volraae across the m.GSOURCE sipated in the unknown is a function of the current
terminals to-20 millivolts. This feature is useful impressed by the Model 164 current source. Power
when testing relays and switches to determine if a developed. Worst-case, is dependent on the range sel-
"dry circuit" contact is present. (For a discussion ected and the compliance limit.
of "dry circuit" measurements, refer to ASTM Specifi-
l
cation 8539-70.) 1. Volt Limit Mode. I" this mode, the compliance
NOTE voltage limit is set at 20 millivolts. The w"rst
MeaS"reme"LS performed in VOLT LIMIT InOde case power dissipation would be a function of " x I
should be used for approx. readi",qs & as shown in Table 2-6.
since a portion of the mn Source current
is shunted through the limit resisror TABLE 2-6.
(R1210, 1211, 1212, 1213, or 1214) as
shown on schematic 262420.
For "dry circuit:' testing, set SOURCEswitch to VOLT
LILlIT. If an on-scale reading is indicated. the" 10 mn 20 In" 2 InilliwattS
switch to OPERATE mode and record resistance of the 100 mn 20 m" 200 microwatts
display. If an over-range condition is indicated then 1 0 20 In" 20 microwatts
a "dry circuit" open condition is present. since the 10 n 20 m" 2 miCrowattS
valcage is limited to 20 mV, the 164 canmt breakdown 100 n 20 m" 0.2 microwatt
the contact resistance unless switched CO OPERATE
2. OPERATE "ode. I" OPERATE mode, the power
dissipation is a funcrion of range selected es
care should be taken t" amid a transient shown in Table 2-7.
current pulse which may result from an over-
shoot of the SOURCESwitch when switching g. Milliohmmeter Zero Adjpsc. set the source
from ZERO to VOLT LIMIT positions. When Switch to ZERO. the Mode Switch to 10011 (or Lhe de-
making dry circuit measurements, the re- sired range), and the Range Switch t" 1 mV. Connecr
commended procedure is to check the read- the unknown to the four terminals as described in
ing in VOLT LIMIT mode, Lhen switch to ZERO paragraph 2-9a. Adjust the Milliohmeter Zero con-
to adjust for zero offsets before taking a trol to give a zero reading with a flashing r display.
reading in OPERATE.
CAOTION
The transient voltage which can be generated
I by avershoor of the SOURCE Switch could be as
large as 15 volts. This voltage transient may
be sufficient to explode devices such as det-
"namrs and squibs if measured in the milli-
I obmneter mode.
I
.o
9
0414
OPmATING niSTR"CTIONS MODELS 164, 16433
NOTE
The maximum conc~nuous input voltage is
:lOOO volts an the 1000 volf xange.
"erS"S Currenf lneasurements are required. since the
mR currenf source in rhe Model 164 has a compliance
voltage range up to 2 volts, the Model 164 can be
used for material resting or semiconductor diode 1. when the Range Switch is placed in Ampere t),; 4
checkout using the ranges given in Table 2-8. positions 100 "A through 1000 mA, the MultimeLer
digit.31 display indicates the voltage across a
calibrated, self-contained resistor. The Range
TABLE 2-8. Switch au~amatically selects the calibrated
V-I Characteristic Measurements ran e resistor for current measurements from 1 x
lo- 7 to 1 ampere full range.
ode setting current Range setting Full Range.
2. The Range Switch is designared in conven-
10 mn 100 mA 1 rn" 10 mn ient engineering units, "A (nanoamperes), PA
100 mn 10 "IA 1 "I" 100 mn (microamperes) and al.4 (milliamperes) with the
1 0 lti 1 In" 1 0. decimal point automatically positioned in the 3
10 n 0.1 n!A 1 El" 10 n display.
100 ii 0.01 mA 1 In" 100 0
3. me full-scale current is determined by the ,
10 mn 100 DA 10 mv* 100 mn* Range Switch. Refer to Table 2-9 for the full-
100 ms2 10 * 10 Ill"* 1 n* range current ranges available on the Model 164.
1 n ImA 10 mv* 10 n*
10 0 0.1 mA 10 mv* 100 **
100 n 0.01 In4 10 nlv* 1000 n*
-
10 Inn 100 mA 100 a"* 1 ** Ampere Range
100 nIlI 10 mA 100 "Iv* 10 n*
1 n 1mA 100 In"* 100 n*
10 n 0.1 mA 100 In"* 1000 n* 1 x 10-7
100 ;! 0.01 mA 100 "Iv* 10 kn* 1.x 10-6
1 x 101;
10 In<, 100 mA 1 v* 10 ** 1 x 1om3
100 mn 10 mA 1 v* 100 n* 1 x 10-2
1 2 1mA 1 v* 1000 cl* 1 x 10
10 !I 0.1 nA 1 v* 10 k&l* 1 x 10-l
100 P 0.01 m.4 1 v* 100 ki2" I
*NOTE: Decimal point 1ocacion is not indicated when C. ohmmeter Display.
the Range Swirch is set fo any posirion other than ~mv,
since all decimal points will be lighted. However, 1. When rhe Range Switch is placed in Ohms posi-
decimal paint can be determined by a sample calculation tions 100 n through 1000 MO, the Multimeter digital
uf V : I for a given range. display designates the valrage across the unknown
resistor with a fixed current applied.
2-10. DIGITAL DISPLAY OPERATION.
2. The Range Switch is designated in convenient
engineering units, 0 (ohms), KO (kilohms) and M,i
(megohm) with the decimal point automatically
1. When the Range Switch is placed in voltage positioned in the readout.
positions 1 mv through 1000". the digital display /
ind*caCes the actual voltage measured. 3. The full-scale resistance is determined by
the Lange Switch. Refer to Table 2-10 for the full-
2. me Flange SWifCh is designated in convenienr range resistance ranges available on the Model 164. ,
engineering units, rn" (millivolt*) and " ~"OlCS)
with the decimal point automacica11y positioned in TABLE Z-10.
the display. Resistance Display
3. me full voltage range is determined by the
Range Switch.
1 x lo2
4. A" overrange display up to a maximum of 1999 1 x 103
is provided by an overrange "I" Lndicator. 1 x 104
For an input greater than 1999, all digits will be 1 x 105
blanked except the overrange "1" indicator. The 1 x 106
polarity indicator will remain lighted indicating 1 x 10' i
the correct polarity. TO remo"e an overload con- 1 x lo8
dition,
position
change the Range Switch to a lees sensitive
or decrease the input signal magnitude.
1 Y 109
01 4
0474
OPERATING INSTR"CTIONS
h. Set the Range Switch to Amperes positions 1000
mA to 100 "ii while checking the readout so that *era
a. me low terminal can be floated above CASE is indicated 0" all ranges.
ground by removing the shorting link between the I.0
and CASE. 1salatian from circuit ground to chassis i. RemoVe the Short circuit at the input terminals
0 ground is greater than 100 megohms shunted by less
than 0.02 microfarad. Circuit ground may be floated 1. Volts Ranges. me in?.trument will normally
up to k500 volts with respect LO chassis ground in read off zero a small nmount o" the 1 m" through
the voltage and current modes. 100 In" ranges because Of sensitivity co random
noise. The readout should remain at zero on the
b. When the inserument is used far off-ground ranges 1" through 1000".
voltage or current measurements, rhe low terminal is
at floating potential. The instrument case ground 2. Ohms Ranges. All Ohms ranges should indicate
should be connected to earth ground through the line a readout overload where all digits except a "1" in
and ground terminal. The shorting link between LO the overrange position are blanked.
and CASE must be disconnected.
3. Amperes Ranges. All current ranges should
indicate a zero readout, except for noise fluctuations.
4 j. After the preceding checkout is made, the in-
strument should be useable for a11 measurements WiCh
2-12. ANALOG OUTPUT. me instrumenr has an analog no further adjustments necessary.
output of 21 volt (non-inverting) at up to 1 milli-
ampere for recording purposes. For off-ground oper-
ation, the analag 21 volt OUTPUT should not be con-
nected unless a" external recorder is capable of
floating at !500 volts with greater than 100 megohms
iSOl&iO".
2-13. ZERO AD.J"STmNTS. 2-14. DIGITAl. OUTPUTS AND EXTERNAL CONTROLS.
a. Short Lhe input terminals with a 10" terminal a. General.
connection - preferably a short copper wire or clip
1. The Model 1602 Oigiral Output Kit provides
opriona1 BCO OUtputS and controls.
range. 2. Included is a 50-pin PRINTEK/CONTROL Connector
(receptacle) for mounting an the instrument rear
C. set the front pane1 zero control (P.1215) to panel.
the full clockwise position.
3. An output buffer card plugs into a prewired
d. If the digital display does not indicate +11 connector on the chassis for either factory or user
to +13 mv, use the rear panel ZERO Control to adjust installation. Buffer card replaces PC-255 inter-
the instrumenr. connecting card.
e. Readjust front panel zero. zero is indicated b. OUtpUt Codes and Levels.
by flashing t polarity lights.
1. The PRINTER/CONTROL 0"fp"tS are Binary Coded
f. Check for zero reading on all ranges fro" 10 In" oechl (~0) ~lgnals with I-2-4-8 standard code.
to 1000 ".
2. me standard signal levels are as follows:
NOTE
output l.Qgic "1" see Table 2-11 (pg. 12)
If there is an off zero reading on the 1 volr
range, it "ill be necessary to adjust CT`? cm- output Logic "0" see Table 2-11 (pg. 12)
RENT OFFSET ADJ. 0" the underside of the chassis.
Refer to Figure 18.
3. me Buffer stages uti1i7.e "Open Collector"
g. set the Range Switch to ohms positions 1000 m O"Lp"t transistors.
to 100 n while checking the readout so that zero is
indicated 0" all ranges.
NOTE c. OUtpUt Information.
If clip leads are used on the input terminals,
the lead resistance may be indicated on the
100 n range since the last digit sensitivity
is 0.1 n per digit.
0474 11
OPERATING INSTRUCTlONS MODELS 164, 164TT
TABLE 2-l'.
Model 1602 Outputs
i i
rJICITAL OUTPUT: Em (1, 2, 4, 8) open collector OUTPUT LOGIC LEVELS:
logic (Motorola MC 858P) represents each of 3 output Logic "1": open transistor coll