Keithley 193A Service manual
Instruction Manual
Model 193A
System DMM
01985, Keithley Instruments, Inc.
Instrument Division
Cleveland, Ohio, U.S.A.
Document Number 193A-901-01
SAFETY PRECAUTIONS
The following safety precautions should be observed before operating the Model ~193A
This instrument is intended for use by qualified personnel who recognize shock huxds .~nd are i,lmiliar
with the safety precautions required to avoid possible injury. Read WET the manual carefully before operating
this instrument.
Exercise extreme caution when a shock hazard is present at the instrument’s input. The American National
Standards Institute (ANSI) states that a shock hazards exists when voltage levels greater than 3OV rms or
42.4V peak are present. A good safety practice is to expect that a hazardous voltage is present in any unknown
circuit before measuring.
ect the test leads for possible wear, cracks or breaks before each use. If any defects are found, replxe
Ins
.R
test leads that have the same measure of safety as those supplied with the instrument.
wt
For optimum safety do not touch the test leads or the instrument while power is applied to the circuit under
test. Turn the power off and discharge all capacitors, before connecting or disconnecting the instrunwnt.
Always disconnect all unused test leads from the instrument.
Do not touch any object which could provide a current path to the common side of the circuit under lest
or power line (earth) ground. Always make measurements with dry hands while standing on ‘1 dry, ills&ted surface, capable of withstanding the voltage being measured.
Exercise extreme safety when testing high energy power circuits (AC line or mains, etc). Refer to the t ligh
Energy Circuit Safety Precautions found in paragraph 2.6 (Basic Measurements).
Do not exceed the instrument’s maximum allowable input as defined in the specifications and operation
section.
SPECIFICATIONS
DC VOLTS
MAXIMUM
READING RESOLUTION
RANGE (5% Digits) 6% 5%
200mV 219.999mV 10” n” 1 IrV
2 V 2.19999 V 1 $V lop”
20 V 21.9999 V
200 V 219.999 V 100 ,,V
1000 v 1000.00 v
*When properly zeroed. **Multiply digit error by 10 for h%~digit accuracy.
10 &V 100 &V
lm”
1mV 1OmV
INPUT 24
RESISTANCE 23O+l”C 23’*5T
>lCX
>lCx 0.002+
1OMCl 0.003+
1OMR 0.003+1 O.O07+l
1OMR 0.004+1
ACCURACY (5% Digits)”
* t%rdg +
Hr.,
0.003+2* 0.005+2’
1
1
counts)
90 Days,
0.005+2
0.007+1
0.007+1
TEMPERATURE
COEFFICIENT
1 Yr.,
23’f5”C O”-18’C & 28--5O~C TIME”*
0.00x+2* o.wK? in 1
0.007+2
0.009+3 (1.lx)O7+O.l
0.009+3 O.WO7
0.009+5 0.0007+0.1
“‘To (1.01% of step ch.qe.
it%rdg+countsli~~ C SETTLING ~
(l.WOS +~ 0. I
+o. I
ANALOG 1
< zms
i
< 1,115
< I”,>
< lms
< I”,5
NMRR: Greater than 60dB at 50 or 60Hr. MAXIMUM MEASUREMENT RATES (into internal
CMRR: Greater than
(with lk0 in either lead).
120dB at dc and 50 or 6OHz
MAXIMUM ALLOWABLE INPUT: 1OOOV peak.
memory, filter and multiplex off):
3% Digit
1000 rdgis
4% Digit 5% Digit
333 rdgls 25 rdg:s
6’12 Digit
25
rdg s
TRMS AC VOLTS (Option 1930)
MAXIMUM
READING
RANGE
2" 2.19999"
2ov
2oov 219.999"
700" 700.00
*Above 2000 COUPES. **Above 20000 counts; 3%+500 typical below 20000. “‘Multiply digit erwr by ill for 6’.:-digit .~cur.xy. ~
(5% Digits)
21.9999"
v
RESOLUTION + t%rdg + counts, 1 Year, 18’.28 c
6% 5%
1 Ir”
10 /Lv
100 PV
1mV
100 flv
10 pv
1mV 1+ 100 0.25+
lOmV 1+100
20Hz-50Hz’
1 + 100
1+ 100
ACCURACY (5% Digits)‘*’
50Hz-IOkHz’
0.25+
I(10
0.25+100
100
0.35+100
IOkHz-20kHz’ ZOkHz-100kHz”
11.35 + 300
L1.35
13.31+ 3Nl
0.5 4~ SW
+ SW
I f so0
I f xx1
I _ 3ki
I + SiHl
RESPONSE:
CREST FACTOR: Rated accuracy to 3.
pulse widths > lops, peak voltage 5 1.36 x full scale.
True root mean square, ac or
ac+dc.
Specified for
AC+DC: Add 60 counts to specified accuracy.
MAXIMUM INPUT: 1OOOV peak ac + dc, 2 x lO’V*Hr.
SETTLING TIME: 0.5s to within 0.1% of change
reading.
INPUT IMPEDANCE: 1Mfi shunted
by
less than 120pF.
TEMPERATURE COEFFICIENT CO’=-18°C & 28’-50°C):
Less than *(0.1x applicable accuracy specification)i”C
below 50kH.z; (0.2x) for 50kHz to 100kHr.
200mv
2"
20
200
700
100 pv
ImV 2+3
v
v
v
1OmV 2+3
100mV 2+3
1 v
2+3
2+3
3dB BANDWIDTH:
CMRR: Greater than
balance).
dBV (Ref. = 1V):
in
INPUT ZOHz-ZOkHz ZOkHz-1WkHr RESOLUTION
14 to +57dHV
(2OOmV t* 7WV rms) 0.2
-34 to 14dUV
(20mV t0 2OOmV) I .s S’
‘Typical
500kHr typical.
6OdB at 50 and 6OHr (Ikl2 1111. ~
ACCURACY +dBV
1 Year. In~-zn c
11.4
,J OldH\’
i)~illdH\
!
OHMS
MAXIMUM CURRENT
READING RESOLUTION THROUGH
RANGE (5% Digits) 6% 5’,2
200 n 219.999 n 100 po lmfl ImA
2 kO 2.19999 k!I ImIl 1Omfl ImA
20 kn 21.YYYY k0 Nllll~
200 kR 219.999 kll 1OOmR 1 n 10 I”A
2Mfl 2:19999Mn 1 R ‘IO n 14
20Mll 21.9999MQ 10 n 100 a 100 nA
200Mn 21Y.YY9Mn 100 R 1 kn 100 nA**
*When properly zeroed.
***4-terminal accuracy 200S20k range. Multiply digit error by 10 for 6’/zd accuracy.
**Nominal short circuit current.
1oomn 100 &A
UNKNOWN
ACCURACY (5% Digits)***
-t (%rdg + counts)
24
Hr.,
230
* 1°C
0.0035+2* 0.007+2* 0.010+2*
0.0035+2 0.007+2 0.010+2
0.0035+2 0.007+2 0.010+2
0.0035+2 0.007+2 0.010+2
0.005 +2 0.010+2 Ll.o10+2
0.040 +2 0.070+2 0.070~2
3.2 +2 3.2 +2 3.2 +2
90 Days, 1 Yr.,
23’ i ST 230 i5T
TEMPERATURE
COEFFICIENT
*(%rdg+counts)/“C
O”lBoC & 28’-5O’C
0.001+0.7
0.001+ 0.1
0.001+0.1
0.001+0.1
0.001+0:1
0.010+0:1
0.230+0.1
CONFIGURATION:
MAXIMUM ALLOWABLE INPUT: 350V
250V rms.
Automatic 2. or 4.terminal.
peak or
DC AMPS (Option 1931)
ACCURACY
(5% Digits)
(S/2 v,ges, 1
RESO- RESO- (1 Year) (1 Year) COEFFICIENT
LUTION *(%rdg+counts)*(
RANGE 15% Dieits)
RANGE (5% Digits)
200 pA InA 0.09+10
20mA lOOnA
200mA l@A
LUTION *(%rdg+counts) -t(%rdg+counts)i”C
2mA 10nA 0.09+10
2 A lo+4
18*28”C
18*28”C
0.091-10 0.01+0.5
0.09+10 0.01+0.5
o.o9+1O 0.01+0.5
TEMPERATURE
0’
00-18T & 280-SOT
0.01+0.5
0.01+0.5
TRMS AC AMPS (Options 1930 and 1931)
ACCURACY*
RESO-
LUTION +(%rdg+counts) -t(%rdg+counts)/“C
RANGE (5% Digits)
GO fill
2mA 1OnA
20mA IOOnA
200mA
2 A 10fiA
*Abwc 2000 counts.
‘InA
‘IpA
45Hz to
1OkHz
(5% Digits) TEMPERATURE
(1 Year) COEFFICIENT
180-28°C
0.6+300 0.04+10
0.6+300
0.6+300
0.6+300
0.6+300
0”-18”C & 28%5O’C
0.04+10
0.04+10
0.04+10
0.04+10
MAXIMUM OPEN CIRCUIT VOLTAGE: 7V
OVERLOAD PROTECTION: 2A
accessible.
fuse (25OV), externally
MAXIMUM VOLTAGE BURDEN: 0.25V on 200pV
through 20mA ranges; 0.28V on 200mA range; 1V on
2A range.
RESPONSE:
CREST FACTOR:
pulse width > lms, peak current 5 1.36 x full scale.
True root mean square, ac or ac+dc.
Rated accuracy to 3. Specified for
MAXIMUM VOLTAGE BURDEN: 0.25V on 2OOpV
through 20mA ranges; 0.28V on 200mA range; 1V on
2A range.
OVERLOAD PROTECTION: 2A
accessible.
SETTLING TIME: 0.5s
reading.
to within 0.1% of change in
fuse (25OV), externally
dB (Ref. = ImA):
ACCURACY + dB
1 Year, 18O-28°C
INPUT
-34 to +66dB
20pA to 2A
-54 to -34dB
2pA t” 20/~/I
45Hz-10kHz
0.3
2
RESOLUTION
O.O~ldB
O.OldU
TEMPERATURE
THERMO-
COUPLE
TYPE RANGE
-100 to + 760°C O.l”C
J
K -100 t” +1372”C O.l”C
T
R 0 to +1768”C 1 “C
-100 to + 400°C O.l”C
E - 100 to + 1000°C O.l”C kO.h”C
s 0 to c176PC 1 “C *3 “C
B
c350 t” +1821”C 1 “C
(Thermocouple) (over IEEE Blrs only)
ACCURACY=
(1 Year)
RESOLUTION 113°-28”C
10.5”C
+0.5”C
+0.5oc
*3 “C
1-5 “C
‘Relative to external 0°C reference junction; exclusive of ther-
mocouple errors. Junction temperature may be external.
TEMPERATURE
(RTD)
4-WIRE
RESO- ACCURACY* TEMPERATURE
RANGE LUTION 1 Yr.,
1000 to
+63O”C O.O05~C)/~C
148O to
+llOO”F 0.01 ‘F)PC
*Excluding probe errors.
O.Ol"C
O.Ol”F 10.36OF
18°-2~oC
*o.lt?"c
COEFFICIENT
* (0.0013% +
*(0.0013%+
RTD TYPE: 1000 platinum; DIN 43 760 or IPTS-68, alpha
0.00385 or 0.00392, 4.wire.
MAXIMUM LEAD RESISTANCE (each lead): 4.wire,
10R.
SENSOR CURRENT: 1mA
COMMON MODE REJECTION: Less than 0.005”CIV at
dc, 50Hz and 60Hz (lOOn unbalance, LO driven).
MAXIMUM ALLOWABLE INPUT: 350V peak, 250V
*Ins.
IEEE-488 BUS IMPLEMENTATION
Multiline Commands: DCL, LLO, SDC, GET, GTL,
UNT, UNL, SI’E, SI’D.
Uniline Commands: IFC, REN, EOI, SRQ, ATN.
Interface Functions: SHl, AHl, TEO, LA, LEO, SRl, RLZ,
PPO, DCl, DTl, CO, El.
I’rogrammable Parameters: Range, Function, Zero, Inte-
gration Period, Filter, dB Reference, EOI, Trigger, Ter-
minator, Delay, 500-rd P Storage, Scaling, Calibration,
Display, Multiplex Of, Status, Service Request, Self
Test, Output Format.
GENERAL
DISPLAY: 14, 0.5.in. alphanumeric LED digits \vith
decimal point and polarity. Function and IEEE bus
status also displayed.
RANGING: Manual or fast autoranging.
ISOLATION: Input LO to IEEE LO or power line
ground: 500V max., 5xlOSV.Hz; greater than ~10%
paralleled by 400pF.
DATA MEMORY: I to 500 locations, progrumwble,
Measurement intervals selectablr lms to 999.999x-c or
triggered.
BENCH READING RATE: 5 readingswr, vwpt 2O~lIl;
ZOOMR range 2 rcadingsisec.
ZERO: Control subtracts on-scale value from subsequent
readings or allows value to bc programmed.
FILTER: Weighted average (exponential). Programmable
weighting: 1 to &
WARMUP: 1 hour to rated accuracy.
OPERATING ENVIRONMENT: [I’,-50 C’, 0% to 809,
relative humidity up to 35’C; linearly derate 3%
RH/“C, 35°C to 50°C (except 2OOMII range: 0% TV, M1”,>
RH up to 28°C).
STORAGE ENVIRONMENT: -25~~ to +65-C.
POWER: 105.725V or 210.250V (internal switch selected),
50Hz or 6OHz, 40VA maximum 90.I~ItlV & 180.22O\’
versions available upon request.
CONNECTORS: Analog: Switch selectable front (lr rear,
safety input jacks. Digital: TRIGGER input and \‘(>I-.I-
METER COMPLETE output on rear panel, BSCs.
DIMENSIONS, WEIGHT: 89mm high x 43Hmm wide
x 441mm deep (3% in. x ~17% in. x 171% in.). Set
weight 33kg (15 Ibs.).
ACCESSORlES AVAILABLE:
Model 1600A: Hi h Voltage Probe
Model 1641: K&n Test Lead Set
Model 1651: 50.Ampere Shunt
Model 1681: Clip-On Test Lead Set
Model 1682A: RF Probe
Model 1685: Clamp-On Current Probe
Model 1751: General Purpose Test Leads
Model 1754: Universal Test Lead Kit
Model 1930: True RMS ACV Option
Model 1931: Current Option
Model 1938: Fixed Rack Mounting Kit
Model 1939: Slide Rack Mounting Kit
Model 7007-l: Shielded IEEE-488 Cable, lm
Model 7007-2: Shielded IEEE-488 Cable, 2m
Model 7008.3: IEEE-488 Cable, 3 ft. (0.9m)
Model 7008.6: IEEE-488 Cable, 6 ft. (1.8m)
Specifications subject to change without notice,
TABLE OF CONTENTS
SECTION l-GENERAL INFORMATION
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
INTRODUCTION
FEATURES
..................................................................................
WARRANTY INFORMATION
MANUAL ADDENDA
SAFETY SYMBOLS AND TERMS
SPECIFICATIONS
INSPECTION
USING THE MODEL 193A MANUAL,
GETTING STARTED
ACCESSORIES
............................................................................
.................................................................
.......................................................................
.............................................................
...........................................................................
...............................................................................
........................................................
.........................................................................
..............................................................................
SECTION 2-BASIC DMM OPERATIONS
2.1
2.2
22.1
2.2.2
2.2.3
2.2.4
2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.4
2.4.1
2.4.2
2.4.3
2.5
2.6
2.6.1
2.6.2
2.6.3
2.6.4
2.6.5
2.6.6
2.6.7
2.6.8
2.6.9
2.6.10
2.6.11
2.6.12
2.6.13
2.7
2.7.1
2.7.2
2.8
2.8.1
2.82
INTRODUCTION ...........................................................................
POWER UPPROCEDURES ...................................................................
Line Power ................................................................................
rower-up Sequence ........................................................................
Factory Default Conditions
User Programmed Conditions
FRONT PANEL FAMILIARIZATION
.................................................................
..............................................................
..........................................................
DisplayandIndicators .....................................................................
Controls..
................................................................................
Input Terminals ...........................................................................
Current Fuse ..............................................................................
REAR PANEL FAMILIARIZATION
Connectors and Terminals
.................................................................. 2-4
............................................................
Calibration Switch .........................................................................
Line Fuse .................................................................................
ERROR AND WARNING DISPLAY MESSAGES
BASICMEASUREMENTS ....................................................................
Warm Up Period
Zero ......................................................................................
.....................................................................................
Filter
DC Voltage Measurements
..........................................................................
.................................................................
Low-Level Measurement Considerations.,
TRMS AC Voltage Measurements.
..........................................................
Resistance Measurements ..................................................................
Current Measurements (DC or TRMS AC)
RTD Temperature Measurements
dBMeasurements
......................................................................... 2.17
...........................................................
dB Measurement Considerations and Applications,,
TRMS AC + DC Measurements
TRMS Conslderatmns
DATA STORE
Storing Data
Recalling Data
.......................................................................
.............................................................................. 2-22
............................................................................. 2-22
............................................................................
............................................................
FRONT PANEL PROGRAMS ................................................................
Cursor and Data Entry,
ProgramTEMP
...........................................................................
...................................................................
............................................... 2-5
...................................................
..................................................
......................................... 2-19
1-l
1-l
I-1
l-l
l-1
1-2
l-2
l-2
1-2
1-3
2-l
2-l
2-l
2-I
2-I
2.2
2-2
2-2
2.2
2-4
2-4
2-3
2-5
2-S
2-Y
2-Y
2-Y
2-11
2-12
Z-13
2.14
2-15
2-16
2.17
2-19
Z-20
2-23
2.25
2-25
2-25
i
2.8.3
2.8.4
2.8.5
2.8.6
2.8.7
2.8.8
2.8.9
2.8.10
2.8.11
2.8.12
2.8.13
2.8.14
2.8.15
2.9
2.10
2.10.1
2.10.2
2.10.3
Program AC + DC (Low Frequency AC).
Program dB
Program ZERO
Program FILTER
Program RESET
Program4
Program 90 (Save)
Program
Program 92 (Freq)
Program 93 (Diagnostics).
Program 94 (MX + B Status)
Program 95 (Multiplexer)
Program 96
FRONT PANEL TRIGGERING
EXTERNAL TRIGGERING
External Trigger
Voltmeter Complete.
Triggering Example
...........................
........................
.......................
.......................
............................
.....................
91 (IEEE Address)
.....................
(CAL)
.....................
.......................
...................
....................
.............
..............
...........
...............
...........
...............
SECTION 3-IEEE-488 PROGRAMMING
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
............................
............................
......
......
......
......
......
......
......
......
.............
.............
............. 2-26
............. Z-26
......
......
......
......
......
......
...... 2.29
...... 2.29
......
...... 2.29
......
......
......
......
......
......
...... 2-31
......
......
...... 2.32
2-25
Z-26
2-27
2-27
2.28
2-29
Z-30
2-30
2-30
2-31
2-31
3.1
3.2
3.3
3.3.1
3.3.2
3.3.3
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.4.5
3.5
3.6
3.6.1
3.6.2
3.6.3
3.7
3.7.1
3.7.2
3.7.3
3.8
3.8.1
3.8.2
3.8.3
3.8.4
3.9
3.9.1
3.9.2
3.9.3
3.9.4
3.9.5
3.9.6
3.9.7
3.9.8
3.10
INTRODUCTION
BUS DESCRIPTION..
IEEE-488 BUS LINES
Data Lines
Bus Management Lines
Handshake Lines
BUS COMMANDS
Uniline Commands..
Universal Commands..
AddressedCommands
Unaddressedcommands
Device-Dependent Commands
COMMAND CODES
COMMAND SEQUENCES
Addressed Command Sequence
Universal Command Sequence
...........................................................................
....................................................................... 3-l
........................................................................
................................................................................
....................................................................
..........................................................................
..........................................................................
... . ..................................................................
....................................................................
.....................................................................
...................................................................
..............................................................
........................................................................
................................................................... 3-7
.............................................................
..............................................................
Device-Dependent Command Sequence .....................................................
HARDWARE CONSIDERATIONS
Typical Controlled Systems
BusConnections
..........................................................................
Primary Address Programming.
SOFTWARE CONSIDERATIONS
Controller Handler Software
Interface BASIC Programming Statements
Interface Function Codes
IEEE Command Groups
...................................................................
GENERAL BUS COMMAND PROGRAMMING.
.............................................................
.................................................................
............................................................
.............................................................
...............................................................
...................................................
..................................................................
..............................................
REN(RemoteEnable) .....................................................................
IFC(InterfaceClear)
LLO(IocalLockout)
GTL (Go To Local) and Local
DCL(DeviceClear)
.......................................................................
......................................................................
..............................................................
.......................................................................
SDC(Send Device Clear) ..................................................................
GET (Group Execute Trigger)
..............................................................
Serial Polling (SPE, SPD) ..................................................................
DEVICE-DEPENDENT COMMAND PROGRAMMING
.........................................
3-l
3-2
3-2
3-2
3-2
3-3
3-4
3-4
3-5
3-5
3-5
3-5
3-7
3-7
3-7
3-7
3-7
3-8
3.10
3.10
3-10
3.10
3-11
3.12
3-12
3.1~2
3.13
3.13
3.13
3-n
3-14
3-14
3.14
3-15
ii
3.10.1
3.10.2
3.10.3
3.10.4
3.10.5
3.10.6
3.10.7
3.10.8
3.10.9
3.10.10
3.10.11
3.10.12
3.10.13
3.10.14
3.10.15
3.10.16
3.10.17
3.10.18
3.10.19
3.10.20
3.10.21
3.10.22
3.10.23
3.11
3.11.1
3.11.2
3.12
3.13
3.x3.1
3.X3.2
3.13.3
3.w.4
3.x3.5
3.X3.6
3.w.7
3.13.8
3.x3.9
Execute(X) ...............................................................................
Function(F) ..............................................................................
Range(R) ................................................................................
Zero(Z) .................................................................................
Filter(P)............................................................................~
Rate(S) ..................................................................................
Trigger Mode (T) .........................................................................
Reading Mode(B) ........................................................................
Data Store Interval (Q) and Size (1) ........................................................
Value (V) and Calibration (C)
Default Conditions (L)
Data Format(G) ..........................................................................
SRQ Mask (M) and Status Byte Format. ....................................................
EOI and Bus Hold-Off Modes (K) ..........................................................
Terminator (Y)
Status(U) ...............................................................................
Multiplex (A)
Delay(W) ...............................................................................
Self-Test(J)
Hit Button(H) ...........................................................................
Display(D) ..............................................................................
Reference Junction (0) ....................................................................
Exponential Filter (N)
FRONT PANEL MESSAGES .................................................................
Bus Error ................................................................................
Trigger Overrun Error .....................................................................
BUS DATA TRANSMISSION TIMES ......................................................... 3.37
TRANSLATOR SOFTWARE
Translator Format
Wild Card($)
NEW and OLD ..........................................................................
Combining Translator Words
Combining Translator Words with Keithley IEEE-488 Commands .............................. 3-40
Executing Translator Words and Keithley IEEE Commands
SAVE
LIST
FORGET
.................................................................................... 3-41
..................................................................................... 3-41
............................................................................
.....................................................................
...............................................................................
............................................................................... 3-3’)
.................................................................................
....................................................................
.....................................................................
.........................................................................
..............................................................
... ~, 3.33
................................................................. 3-37
..............................................................
.........................
.........
3.19
3-1~
3-19
3-20
.... 3.20
3.21
3.21
3.22
3.22
3.23
3.24
3-24
3.25
3.28
3.28
3.2’)
3.33
R-33
3-3-1
3-W
3-35
3.36
3.36
3-36
3.37
3.37
3-39
3-3’)
3-40
3.41
SECTION 4-PERFORMANCE VERIFICATION
4.1
4.2
4.3
4.4
4.5
4.5.1
4.5.2
4.5.3
4.5.4
4.55
4.5.6
INTRODUCTION ...........................................................................
ENVIRONMENTALCONDITIONS
INITIAL CONDITIONS.. ....................................................................
RECOMMENDED TEST EQUIPMENT.
VERIFICATION PROCEDURES ......................................................
DC Volts Verification.. .....................................................................
TRMS AC Volts Verification
OHMS Verification
DC Current Verification
TRMS AC Current Verification
RTD Temperature Verification .............................................................
........................................................................
....................................................................
............................................................
........................................................
.................................................................
..............................................................
SECTION 5-THEORY OF OPERATION
5.1
INTRODUCTION ..,,...........,......,....,.,,.,...................................~....~. 5-l
4-l
1-1
4-l
4-I
........ 4-I
1-2
4-3
4-4
4-5
4-h
4-7
iii
5.2 OVERALL FUNCTIONAL DESCRIIJTION
5.3 ANALOG CIRCUITRY .......................................................................
5.3.1
5.3.2
5.3.3
5.3.4
5.4
5.5
5.6
5.6.1
5.6.2
5.7
Input Signal Conditioning
Multiplexer
+Z.lV Reference Source
Input Buffer Amplifier
AIDCONVERTER ...........................................................................
CONTROLCIRCUITRY.. ...................................................................
DIGITAL CIRCUITRY .......................................................................
Microcomputer ...........................................................................
Display Circuitry
POWER SUPPLIES
............................................................................... 5-6
..........................................................................
.........................................................................
..................................................................
.................................................................... 5-8
.....................................................................
.....................................................
SECTION 6-MAINTENANCE
5-l
5-l
5-l
5-8
5-8
5-10
5-10
5-10
5-10
5-10
6.1
6.2
6.3
6.3.1 Line Fuse
6.3.2
6.4
6.5
6.6
6.6.1
6.6.2
6.6.3
6.6.4
6.6.5
6.6.6
6.6.7
6.68
6.6.9
6.6.10
6.6.11
6.6.12
6.7
6.8
6.9 TROUBLESHOOTING
6.9.1 Recommended Test Equipment
6.9.2 Power-Up Self Test .......................................................................
6.9.3 Program 93.Self Diagnostic Program.
6.9.4 Iowa Supplies ...........................................................................
6.9.5 Signal Conditioning Checks
6.9.6 Digital and Display Circuitry Checks
INTRODUCTION
LINE VOLTAGE SELECTION
FUSEREPLACEMENT
Current Fuse.
MODEL 1930 TRMS ACV OPTION INSTALLATION
MODEL 1931 CURRENT OPTION INSTALLATION
CALIBRATION
Recommended Calibration Equipment
Environmental Conditions
Warm-Up Period ..........................................................................
Calibration Switch ......................................................................... 6-5
Front Panel Calibration.
IEEE-488 Bus Calibration
Calibration Sequence .......................................................................
DC Volts Calibration
Resistance Calibration
TRMS AC Volts Calibration
DC Current Calibration.
TRMS AC Current Calibration
DISASSEMBLYINSTRUCTIONS .............................................................
SPECIAL HANDLING OF STATIC-SENSITIVE DEVICES
...........................................................................
.................................................................
.......................................................................
.................................................................................
.............................................................................
............................................
............................................
..............................................................................
.......................................................
..................................................................
....................................................................
...................................................................
....................................................................... 6-7
...................................................................... 6-8
................................................................
...................................................................
............................................................. 6-14
...................................... 6-21
...................................................................... 6-21
............................................................ 6-22
.......................................................
...............................................................
.......................................................
6-l
6-l
6-l
6-l
6-2
6-2
6-3
6-3
6-3
6-3
6-3
6-5
6-6
6-7
6-10
6-13
6-15
6-22
6-23
6-23
6.23
6.23
SECTION 7-REPLACEABLE PARTS
7.1 INTRODUCTION ............................................................................ 7-l
7.2
7.3 ORDERING INFORMATION ................................................................. 7-l
7.4 FACTORY SERVICE.. ........................................................................ 7-l
7.5
iv
PARTS LIST ................................................................................. 7-l
SCHEMATIC DIAGRAMS AND COMPONENT LOCATION DRAWINGS ......................... 7-l
LIST OF ILLUSTRATIONS
2-l
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
Z-10
2-11
3-l
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
3-13
4-l
4-2
4-3
4-4
4-5
4-6
4-7
4-8
Model193A Front Panel
Model193ARearPanel
DC Voltage Measurements
TRMS AC Voltage Measurements
Two-Terminal Resistance Measurements
Four-Terminal Resistance Measurements.
Current Measurements..
RTD Temperature Measurements.. ........................................................... 2-17
External Pulse Specifications
Meter Complete Pulse Specifications
External Triggering Example..
IEEE-488 Bus Configuration
IEEE-488 Handshake Sequence
Command Groups
System Types
Typical Bus Connections
IEEE-488 Connections.
Model 193A IEEE-488 Connector ........
Contact Assignments.
General Data Format
SRQ Mask and Status Byte Format .....
UO Status Word and Default Values
Ul Error Status Word.
Hit Button Command Numbers
Connections for DC Volts Verlflcation .......................................................... 4-2
Connections for TRMS AC Volts Verification
Maximum Input TRMS AC Voltage
Connections for Ohms Verification (200%20kn) Range
Connections for Ohms Verifications (200k0-200MR Ranges).
Connections for DC Current Verification.
Connections for TRMS AC Current Verification
Connections for RTD Temperature Verification. .................................................
........................... ...... ...... 3-8
......................................................................
.......................................................................
...................................................................
............................................................
.......................................................
......................................................
....................................................................
................................................................
.........................................................
...............................................................
.............. ...... ...... ......
...........
......................
.................
...................
...................
................... ...... ...... ...... 3-26
...... ...... ...... ...... 3-30
..................
......... ...... ...... 3-34
............................................................
...... 3-3
...... ...... 3-6
...... 3-x
......
......
...... ...... 3-10
...... ......
...... ......
...................................................
..........................................
.....................................
......................................................
.................................................
...... 3-26
2-7
2-7
2.13
2.14
2-16
2-16
2-16
2-31
2-32
2-33
3-2
3-Y
3-Y
3-32
4-3
4-4
4-4
4-S
4-h
1-7
-1-7
5-l
5-2 Input Configuration During 2 and 4-Terminal Resistance Measurements
5-3 Ohms Source (2k12 Range Shown)
s-4
5-5
5-6
5-7
6-l
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
6-10
Overall Block Diagram ...............................................
....................................
Resistance Measurement Simplified Circuitry
JFET Multiplexer
Multiplexerl’hases .................................................
A/D Converter Simplified Schematic
Models 1930 and 1931 Installation.
DC Volts Calibration Configuration (2OOmV and 2V Ranges)
DC Volts Calibration Configuration (ZOV-1OOOV Ranges),
Four-Wire Resistance Configuration (200%20kO Ranges)
Two-Wire Resistance Calibration Configuration (200k0-ZOOM0 Ranges).
Flowchart of AC Volts Calibration Procedure
TRMS AC Volts Calibration Adjustments.
TRMS AC Volts Calibration Configuration
DC Current Calibration Configuration
TRMS AC Current Calibration Configuration
....................................................
..................................
...........................................................
........................................................
..........................
.....................................
.........................................
.........................................
..................................................
.....................................................
.....................................................
..................................................
...........................
5.2
5.3
i-4
5-j
S-6
j-7
5-9
h-4
b-7
6-S
6-Y
6-9
6-11
6-12
h-l3
6.14
h-15
6-11
6-12
Co”“ectors.....................................................
........................... 6-17
Model 193A Exploded View. ........................... 6-19
7-1 Jumper Board, Component Location Drawing, Dwg. No. 193.160.
7-2 Display Board, Component Location Drawing, Dwg. No. 193.110
7-3
7-4
7-5
7-6
7-7
7-8
Display Board, Schematic Diagram, Dwg. No. 193.116
Digital Board, Component Location Drawing, Dwg. No. 193.100
Digital Board, Schematic Diagram, Dwg. No. 193-106
Analog Board, Component Location Drawing, Dwg. No. 193.120
Analog Board, Schematic Diagram, Dwg. No. 193.126
Model 1,930, Component Location Drawing, Dwg. No. 1930.100
7-9 Model 1930, Schematic Diagram, Dwg. No. 1930.106
710 Model 1931, Component Location Drawing, Dwg. No. 1931-100
7-11 Model 1931, Schematic Location Drawing, Dwg. No. 1931.106
......
......
......
......
......
......
......
......
......
......
......
..............
..............
..............
..............
7-3
7-4
7-5
7-10
.............. 7-11
............. 7.22
.............
7-23
............. 7.34
.............
7-35
............. 7-38
............. 7-39
vi
LIST OF TABLES
2-l
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
3-l
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
3-n
3-14
3-15
3-16
3-17
3-18
Factory Default Conditions
Front PanelPrograms ........................................................................
Error and Warning Messages .................................................................
Internal Filter ...............................................................................
Resistance Ranges ..........................................................................
Corresponding Voltage Reference Levels for Impedance References
Comparison of Average and TRMS Meter Readings.
High Speed Data Store
Example MX + B Readings .................................................................
IEEE-488 Bus Command Summary.
Hexadecimal and Decimal Command Codes
Typical Addressed Command Sequence
Typical Device-Dependent Command Sequence
IEEE Contact Designation
BASIC Statements Necessary to Send Bus Commands
Model 193A Interface Function Codes
IEEE Command Groups.
General Bus Commands and Associated BASIC Statements
Factory Default Conditions
Device-Dependent Command Summary
Range Command Summary
High Speed Data Store
SRQ Command Parameters
Bus Hold-Off Times ........................................................................
Trigger to Reading-Ready Times (DCV Function)
Translator Reserved Words and Character.
Translator Error Messages .................................................................... 3-38
................................................................... 2-l
2.12
2.15
..............................
...........................................
.....................................................................
..........................................................
................................................... 3-5
...................................... ................ 3-7
................................................ 3-7
....................................................................
......................................... 3-11
........................................................ 3.11
.................................................................... 3.12
.................................... 3-12
..................................................................
...................................................... 3-16
.................................................................
....................................................................
..................................................................
..............................................
....................................................
2.19
2-21
2.22
Z-28
3-14
3-20
2-23
3-27
3-28
3-37
3-38
2-4
2-9
3-4
3-9
4-l
4-2
4-3
4-4 Limits for Ohms Verification
4-5
4-6
4-7
5-l
6-l
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-13
Recommeded Test Equipment ..............
Limits for DC Volts Verification .............
Limits for TRMS AC Volts Verification. ......
Limits for DC Current Verification
Limits for AC Current Verification
Limits for RTD Temperature Verification ....
Ranging Information .........................................................................
Line Voltage Selection ........................................................................
Line Fuse Replacement
Current Fuse Replacement
Recommended Calibration Equipment
DC,Volts Calibratiqn .........................................................................
Resistance Calibration .......................................................................
TRMS AC Volts (Model 1930) Calibration
DC Current Cahbratmn
TRMS AC Current Calibration
Static-Sensltwe Devzes
Recommended Troubleshooting Mode
Model 193A Troubleshooting Mode
Power Supply Checks
.......................................................................
......................................................................
.....................................................................
......................................................................
......
......
...............
..........
..........
...................................................................
.........................................................
..................................................... 6-13
...............................................................
........................................................
..........................................................
......
......
......
......
......
......
......
......
......
5.3
6-l
6-2
6-2
6;
6-10
6-14
6-15
6.21
6;:
h-28
vii
6.14
6-15
Digital Circuitry Checks
Display Circuitry Checks
...............................................................
..............................................................
6-28
6-29
7-l
7-2
7-3
7-4
7-5
7-6
Display Board, Parts List
Digital Board, Parts List
Analog Board, Parts List,,
Model 1930, Parts List
Model 1931, Parts List.
..............................................................
..............................................................
............................................................
.................................................................
................................................................
Model 193A Mechanical Parts List
......................................................
......
......
7-2
7-7
715
7-31
7-37
7-41
vttt
SECTION 1
GENERAL INFORMATION
1.1 INTRODUCTION
The Keithley Model 193A System DMM, with the TRMS
AC Volt and Current options installed, is a six function autoranging digital multimeter. At 6% digit resolution, the LED
display can display ~2,200,OOO counts. The range of this
analog-to-digital (A/D) converter is greater than the normal *1,999,999 count AID converter used in many 6% digit
DMMs. The built-in IEEE-488 interface makes the instrument fully programmable over the IEEE-488 bus. With the
TRMS ACV option and the Current option installed, the
Model 193A can make the following basic measurements:
1. DC voltage measurements from 1OOnV to lOOOV.
2. Resistance measurements from 1OOpfl to ZOOMR.
3. RTD temperature measurements from -1OOOC to 63O’C.
4. TRMS AC voltage measurements from I$/ to 700V.
5. DC current measurements from 1nA to 2A.
6. TRMS AC current measurements from 1nA to 2A.
In addition to the above mentioned measurement capabilities, the Model 193A can make dB and TRMS AC + DC
measurements.
1.2 FEATURES
Some important Model 193A features include:
the power-up default conditions.
l Translator Software-User defined words can be used to
replace standard command strings over the IEEE488 bus.
l Thermocouple (TC) temperature measurements con be
made over the IEEE-488 bus.
1.3 WARRANTY INFORMATION
Warranty information may be found on the inside front
cover of this manual. Should it become necessary to exercise the warranty, contact your Keithley representative or
the factory to determine the pmper course of action.
Keithley Instruments maintains service facilities in the
United States, United Kingdom and throughout Europe.
Information concerning the application, operation or ser.
vice of your instrument may be directed to the applications
engineer at any of these locations. Check the inside front
cover for addresses.
1.4 MANUAL ADDENDA
Information concerning improvements or changes to the
instrument which occur after the printing of this manual
will be found on an addendum sheet included with this
manual. Be sure to review these changes before attempting to operate or service the instrument.
l 14 Character Alphanumeric Display-Easy to read 14 seg-
ment LEDs used for readings and front panel messages.
l High Speed Measurement Rate-1000 readings per
second.
l Zero-Used to cancel offsets or establish baselines. A zero
value can be rogrammed from the front panel or over
the IEEE-488 & us.
l Filter-The weighted average digital filter can be set for
1 to 99 readings from the front panel or over the bus.
l Data Store-An internal buffer that can store up to 500
readings is accessible from either the front panel or over
the bus.
l Digital Calibration-The instrument may be digitally
calibrated from either the front panel or over the bus.
l User Programmable Default Conditions-Any instrument
measurement configuration can be established as
1.5 SAFETY SYMBOLS AND TERMS
The following safety symbols and terms are used in this
manual or found on the Model 193A.
The A
should refer to the operating instructions in this manual.
The M
1OOW or more may be present on the terminal(s). Standard safety practices should be observed when such
dangerous levels are encountered.
The WARNING used in this manual explains dangers that
could result in personal injury or death.
The CAUTION used in this manual explains haz.ards that
could damage the instrument.
symbol on the instrument denotes that the user
on the Instrument denotes that a potential of
l-l
GENERAL INFORMATION
1.6 SPECIFICATIONS
Detailed Model 193A specifications may be found preceding
the Table of Contents of
this
manual.
1.7 INSPECTION
The Model 193A System DMM was carefully inspected,
both electrically and mechanically before shipment. After
unpacking all items from the shipping carton, check for any
obvious signs of physical damage that may have occurred
during transit. Report any damage to
Retain and use the original packing materials in case reshipment is necessary. The following items are shipped with
every Model 193A order:
Model 193A System DMM
Model 193A Instruction Manual
Additional accessories as ordered.
If an additional instruction manual is required, order the
manual package (Keithley Part Number 193-901-00). The
manual package includes an instruction manual and any
applicable addenda.
the
shipping agent.
l Section 6 contains information for servicing the instru-
ment, This section includes information on fuse replacement, line voltage selection, calibration and
troubleshooting.
l Section 7 contains replaceable parts information.
1.9 GETTING STARTED
The Model 193A System DMM is a highly sophisticated in-
strument
and running quickly use the following procedure. For complete information on operating the Model 193A consult the
appropriate section of this manual.
POWW-Up
1. Plug the line cord into the rear panel power jack and
plug
grounded power source. See paragraph 2.2.1 for more
complete information.
2. Press in the POWER switch to apply power to the instrument. The
range.
with many capabilities. To get the instrument up
the
other end of the cord into an appropriate,
instrument
will power up to the 1OOOVDC
1.6 USING THE MODEL 193A MANUAL
This manual contains information necessary for operating
and servicing the Model 193A System DMM, TRMS ACV
option and the Current option. The information is divided
into the following sections:
l Section 1 contains general information about the Model
193A including that necessary to inspect the instrument
and get it operating as quickly as possible.
l Section 2 contains detailed operating information on us-
ing the front panel controls and programs, making connections and basic measuring techniques for each of the
available measuring functions.
l Section 3 contains the information necessary to connect
the Model 193A to the IEEE-488 bus and program
operating modes and functions from a controller.
l Section 4 contains performance verification procedures
for
the
instrument. This information will be helpful if you
wish to verify that the instrument is operating in compliance with its stated specifications.
l Section 5 contains a description of operating theory.
Analog, digital, power supply, and IEEE-488 interface
operation is included.
Making Measurements
1. Connect the supplied safety shrouded test leads to the
front panel VOLTS HI and LO input terminals. Make
sure the INPUT switch is in the out (FRONT) position.
2. To make a voltage measurement, simply connect the input leads to a DC voltage surge (up to 1OOOV) and take
the reading from the display.
3. To change to a different measuring function, simply
press the desired function button. For example, to
measure resistance, press the OHMS button.
Using Data
Store
Storing Data:
1. Press the DATA STORE button. The DATA STORE indicator will turn on and a storage rate (in seconds) will
be displayed.
2. Select an interval, other than 000.000, using the 4 and
w, and data buttons.
3. Press the ENTER button. The buffer size will be
displayed. Size 000 indicates that data will overwrite after
500 readings have been stored.
4. If a different buffer size is desired, enter the value using the number buttons (0 through 9).
5. Press the ENTER button to start the storage process.
1-2
-
GENERAL INFORMATION
The data store mode can be exited at any time before the
start of the storage process by pressing the RESET button.
Once storage has commenced, the storage process can be
stopped by pressing any function button. See paragraph
2.7.1 for complete information on storing data.
Recalling Data:
1. Press the RECALL button. The buffer location of last
stored reading will be displayed.
2. To read the data at a different manor location, enter
the value using the number buttons O-9).
3. Press the ENTER button. The reading and the memory
location will be displayed.
4. The A and 7 buttons can be used to read the data in
all filled memory locations.
5. To read the highest, lowest and average reading stored
in the buffer, press the number 1,2 and 3 buttons respectively. Note that the memory location of the highest and
lowest reading is also displayed. The average reading is
displayed along with the number of readings averaged.
The recall mode can be exited by pressing the RESET but-
ton. See paragraph 2.7.2 for complete information on data
recall.
Y
Paragraph 2.8 provides the detailed information for using
the front panel programs.
1.10 ACCESSORIES
The following accessories are available to enhance the
Model 193As, capabilities.
Model 1301 Temperature Probe-The Model Uol is a rugged low cost temperature probe designed to allo\v temperature measureme”ts from -55 to 150°C.
Model 16008 High Voltage Probe-The Model 1booB extends
DMM measurements to 40kV.
Model 1641 Kelvin Test Lead Set-The Model 1641 has
special clip leads that allow 4-terminal measurements to be
made while making “nly two c”nnectims.
Model 165150.Ampere Current Shunt-The Model 1651 is
an external O.OOlR *l% 4.terminal shunt, which permits
current measurements from 0 to 50A AC or DC.
Model 1681 Clip-On Test Lead Set-The Model 1681 contains two leads, 1.2m (48’) long terminated with banana
plugs and spring action clip probes.
Using Front Panel Programs
Program selection is accomplished by pressing the PRGM
button followed by the button(s) that corresponds to the
program number or name. For example, to select Program
91 (IEEE status), press the PRGM button and then 9 and
1 buttons. Table 2-2 lists and briefly describes the available
front panel programs. Once a
following general rules will
1. A displayed program condition can be entered by pressing the ENTER button.
2. Program conditions that prompt the user with a flashin
digit can be modified usmg the data buttons (0 throug
9 and +) and the cursor control buttons (manual range
buttons).
3. Programs that contain alternate conditions can be
dis K layed by ressin one of the manual range buttons.
Eat press o
between the two available conditions.
4. A program will be executed when the pressed ENTER
button causes the instrument to exit the program mode.
5. A pro ram can be exited at an time and thus not execute 1 , by pressing the RESE
P P
one o these buttons toggles the display
rogram is selected the
P
app y:
if
button.
a
Model 1682A RF Probe-The Model 1682A permits voltage
measurements from 1OOkHz to 250MHz. AC to DC transfer
accuracy is +ldB from 1OOkHr to 250MHz at IV, peak
responding, calibrated in RMS of a sine wave.
Model 1685 Clamp-On AC Probe-The .Model 1685
measures AC current by clamping on to a single conductor. Interruption of the circuit is unnecessary. The Model
1685 detects currents by sensing the changing magnetic field
produced by the current flow.
Model 1751 Safety Test Leads-Finger guards and shroud-
ed banana plugs help minimize the chance “1 making con-
tact with live circuitry.
Model 1754 Universal Test Lead Kit-The Model 1754 is rl
12 piece test lead kit, with interchangeable plug-in accessories. Included in the kit is one set of test leads (l-red,
l-black), two spade lugs, two standard banana plugs, two
phone tips (0.06 DIA.), two hooks and miniature alligator
clips (with boots).
Model 1930 TRMS AC Volt 0
True Root Mean Square (TRM
Model 193A. This option allows the instrument to measure
the TRMS value of an AC signal. When the Model 1Y30
tion-The Model 1930 is d
! ) AC plug-in option for the
1-3
is installed, AC + DC voltage measurements can be made.
Field installation or removal/replacement of the Model 1930
will require recalibration of the Model 193A and the Model
1930.
Model 1931 Current 0
current option for the R
tion-The Model 1931 is a plug-in
ode1 193A. This option allows the
instrument to measure DC current up to 2A. When both
Models 1930 and 1931 are installed, the instrument can
make TRMS AC current measurements and TRMS AC +
DC current measurements. Field installation requires
recalibration of the Model 193A.
Model 7007 IEEE488 Shielded Cables-The Model 7007 connects the Model lY3A to the IEEE-488 bus using shielded
cables to reduce electromagnetic interference (EMI). The
Model 7007-l is one meter in length and has a EMI shielded IEEE-488 connector at each end. The Model 7007-Z is
identical to the Model 70071, but is two meters in length.
Model 7008 IEEE-488 Cables-The Model 7008 connects the
Model 193A to the IEEE-488 bus. The Model 7008-3 is 0.9m
(3 ft.) in length and has a standard IEEE-488 connector at
each end. The Model 7008-6 cable is identical to the Model
7008.3, but is 1.8m (6 ft.) in length.
Model 1938 Fixed Rack Mount-The Model 1938 is a stationary mount kit that allows the Model 193A to be
mounted in a standard 19 inch rack.
Model 1939 Slide Rack Mount-The Model lY39 is a sliding
mount kit that allows the Model 193A to be rack mounted
with the added feature of sliding the instrument forward
for easy access to the rear panel and top cover.
Model 8573 IEEE-488 Interface-The Model 8573 is an
IEEE-488 standard interface designed to interface the IBM
PC or XT computers to Keithley instrumentation over the
IEEE-488 bus. The interface system contains two distinctive parts: an interface board containing logic to perform
the necessary hardware functions and the handler software
(supplied on disk) to perform the required control functions. These two important facets of the Model 8573 join
together to give the IBM advanced capabilities over
IEEE-488 interfaceable instrumentation.
1-4
SECTION 2
BASIC DMM OPERATION
2.1 INTRODUCTION
Operation of the Model 193A may be divided into two The instrument can be turned on by pressing in the front
general categories: front panel operation and IEEE-488 bus panel POWER switch. The switch will be at the inner most
operation. This section contains information necessary to
use the instrument from the front panel. These functions
can also be programmed over the IEEE-488 bus, as described in Section 3.
2.2 POWER UP PROCEDURE
2.2.1 Line Power
Use the following procedure to connect the Model 193A to
line power and power up the instrument.
1. Check that the instrument is set to correspond to the
available line oower. When the instrument leaves the factory, the internally selected line voltage is marked on the
rear panel near the AC power receptacle. Ranges are
105Vl25V or ZloV-250V 50160Hz AC. If the line voltage
setting of the instrument needs to be changed, refer to
Section 6, paragraph 6.2 for the procedure. If the line
frequency setting of the instrument needs to be checked
and/or changed, utilize front panel Program 92 (see
paragraph 2.8.11) after the instrument completes the
power-up sequence.
2. Connect the female end of the power cord to the AC
receptacle on the rear panel of the instrument. Connect
the other end of the cord to a grounded AC outlet.
WARNING
The Model 193A is equipped with a 3-win? power
cord that contains a separate ground wire and
is designed to be used with grounded outlets.
When proper connections are made, instrument
chassis is connected to power line ground.
Failure to use a grounded outlet may result in
personal injury or death because of electric
2.2.2 Power-Up Sequence
position when the instrument is turned on. Upon P owerup, the instrument will do a number of tests on itse f. Tests
are performed on memory (ROM, RAM and NVRAM). If
RAM or ROM fails, the instrument will lock up. If EYROM
FAILS, the message “UNCALIBRATED” will be
See paragraph 6.92 for a complete description of the pw~erup self test and recommendations to resolve failures.
2.2.3 Factory
At the factory, the Model 193A is set up so that the front
panel controls and features are initially configured to certain conditions on power-up and when program RESET is
run. These are known as the factory default conditions and
are Iisted in Table 2.l,
Default Conditions
displayed.
Table 2-1. Factory Default Conditions
Function
Range
Resolution
Line Frequency
IEEE Address
RTD Alpha Value and scale
ZW”
Zero Value
dR
dB Reference Value
AC + DC
Data Store
Recall
Filter
Filter Value
DCV
1ooov
6% Digits
1
f
0.00392LC
Disabled
+ooooooo
Disabled
IV, 1mA
Disabled
Disabled
Disabled
Disabled
10
shock.
‘Program 90 (save) can be used to establish the factory
CAUTION
Be sure that the power line voltage agrees with
the indicated range on the rear panel of the instrument. Failure to
ObSSNS
this
pmCautiOfl
may
default condition. However, an “UNCALIBRATED” error
will set factory default to an IEEE address of 10 and a irequency setting of 60Hz.
result in instrument damage.
2-1
2.2.4 User Programmed Conditions
A unique feature of the Model 193A is that each function
“remembers” the last measurement configuration that it
was set up for (such as range, zero value, filter value, etc).
Switching back and forth between functions will not affect
the unique configuration of each function. However, the
instrument will “forget” the configurations on power-down.
Certain confi urations can be saved by utilizing front panel
Program 90. % n power-up, these user saved default condi-
tions will prevail over the factory default conditions. Also,
a DCL or SDC asserted over the IEEE-488 bus will set the
instrument to the user saved default conditions. For more
information, see paragraph 2.8.9 (Program 90).
NOTE
Keep in mind that power-up default conditions can
be either factory default conditions or user saved
default conditions.
2.3 FRONT PANEL FAMILIARIZATION
The front panel layout of the Model 193A is shown in Figure
2-l. The following paragraphs describe the various components of the front panel in detail.
POWER-The POWER switch controls AC power to the in-
strument. Depressing and releasing the switch once turns
the power on. Depressing and releasing the switch a second time turns the power off. The correct positions for
on and off are marked on the front panel by the POWER
switch.
INPUT-The INPUT switch connects the instrument to
either the front panel input terminals or the rear panel in-
put terminals. This switch operates in same manner as the
power switch. The front panel input terminals are selected
when the switch is in the “out” position and the rear panel
input terminals are selected when the switch is in the “in”
position.
FUNCTION GROUP-The FUNCTION buttons are used
to select the primaly measurement functions of the instru-
ment. These buttons also have secondary functions.
DCV-The DCV button places the instrument in the DC
volts measurement mode. The secondary function of this
button is to enter the number 0. See paragraph 2.6.4 for
DCV measurements.
Am-With the ACV option installed, the ACV button places
the instrument in the AC volts measurement mode. The
secondary function of this button is to enter the number
1. See paragraph 2.6.6 for ACV measurements.
2.3.1 Display and Indicators
Display-The 14 character, alphanumeric, LED display is
used to display numeric conversion data, range and function mnemonics (i.e. mV) and messages.
Status Indicators-These three indicators apply to instrument operation over the IEEE-488 bus. The REMOTE indi-
cator shows when the instrument is in the IEEE-488 remote
state. The TALK and LISTEN indicators show when the in-
strument is in the talk and listen states respectively. See
Section 3 for detailed information on operation over the
bus.
2.3.2 Controls
All front panel controls, except the POWER and INPUT
switches, are momentary contact switches. Indicators are
located above certain feature buttons to show that they are
enabled. Included are AUTO (autorange), ZERO, FILTER,
RECALL and DATA STORE. Some buttons have secondary
functions that are associated with front panel program
operation. See paragraph 2-8 for detailed Information on
front panel programs.
OHMS-The OHMS button places the instrument in the
ohms measurement mode. The secondary function of this
button is to enter the number 2. See paragraph 2.6.7 for
resistance measurements.
ACA-With the ACV option and current option installed,
the ACA button places the instrument in the AC amps
measurement mode. The secondary function of this but-
ton is to enter the number 3. See paragraph 26.8 for ACA
measurements.
DCA-With the current option installed, the DCA button
places the instrument in the DC amps measurement mode.
The secondary function of this button is to enter the
number 4. See paragraph 2.6.8 for DCA measurements.
TEMP-The TEMP button places the instrument in the RTD
temperature measurement mode. The secondary functions
of this button are to select the TEMP program (select alter-
nate alpha value and thermometric scale) and to enter the
number 5. See paragraph 2.6.9 for RTD temperature
measurements.
RANGE GROUP-The Aand vbuttons are used for
manual ran
ing. These %
ing and the AUTO button is used for autorang-
uttons also have secondary functiolw.
2-2
OPERATION
Manual-Each time the A button is pressed, the instrument will move up one range, while the v button will move
the instrument down one range each time it is pressed.
Pressing either of these buttons will cancel autorange, if
it was previous selected. The secondary functions of these
buttons are associated with front panel program operation.
AUTO-The AUTO button places the instrument in the
autorange mode and turns on the AUTO indicator. While
in this mode, the instrument will go to the best range to
measure the applied signal. Autoranging is available for all
functions and ranges. Autoranging may be cancelled by
pressin f the AUTO button or one of the manual range buttons. T e secondary function of this button is to enter the
* sign.
MODIFIER GROUP-The MODIFIER buttons activate
features that are used to enhance the measurement ca
bilities of the Model 193A. These features in effect ma Ify
a-
1
the selected function. In addition to their primary tasks,
these buttons have secondary functions.
ZERO-The ZERO button turns on the ZERO indicator and
causes the displa ed reading to be subtracted from subsequent readings. -F, his feature allows for zero correction or
storage of baseline values. The secondary function of this
button is to select the ZERO program. Refer to paragraph
2.6.2 for detailed information on the zero feature.
dB-The dB button places the instrument in the dB
measurement mode and may be used with the ACV and
ACA functions. Under factory default conditions, measurements are referenced to 1V or ImA. However, the dB program may be used to change the reference level. The secondary function of this button is to select the dB program.
See paragraph 2.6.10 for dB measurements.
FILTER-The FILTER button turns on the FILTER indicator
and causes the instrument to start weighted averaging a
number (l-99) of readings. The factory default value is 10,
but may be changed using the FILTER program (see
paragraph 2.8.6). See paragraph 2.6.3 for filter operation.
Selecting the FILTER
tions of this button. TK
rogram is one of the secondary func-
e other secondary function is to enter
the number 6.
AC + DC-With the appropriate options installed, the AC
+ DC button (with ACV selected) places the instrument in
the AC + DC measurement mode. With the ACV o
installed, VAC + DC measurements can be made.
tion
%ith
both the ACV and current option installed, AAC + DC
measurements can be made. See paragraph 2.6.12 for AC
+ DC measurements. The secondary functions of this button are to select the AC + DC program (low frequency
TRMS measurements) and to enter the number 7.
CONTROL GROUP-The CONTROL buttons are features
that allow for the control and manipulation of various
aspects of instrument operation. All of these buttons, except PRGM, have a secondary function.
RESOLN-The RESOLN button allows for the selection of
the number of digits of display resolution. Each press of
the RESOLN button increases resolution by one digit.
Pressing the RESOLN button after the maximum resolu-
tion is reached will revert the display back to the lowest
resolution. Dis
can be selecte B
lay resolution of 3%, 4’12, 5% or 6% digits
for DCV and ACV. Display resolution of
4% or 5’/2 digits can be selected for DCA and ACA. On
OHMS, Y/z, 4% 5% and 6% digit resolution is available on
the ZOOR through 200kfl ranges. On the 2MQ and 20MR
ranges, 5% and 6% digits can be selected. On the 200MR
ran e, only 5%d resolution is available. The RESOLN button a as no effect on low frequency AC + DC (Program AC
+ DC), TEMP or dB measurements. The secondary func-
tion of this button is to enter the decimal point (.).
TRIGGER/ENTER-The TRIGGER/ENTER button is used
as a terminator for data entry when the instrument is in
the front panel program mode and as a front panel trigger
when the data store is active.
STATUS/RESET
STATUS-Instrument status can be displayed when the in-
strument is in the normal measurement mode or logRing
readings. When the STATUS button is first pressed, the
following current instrument conditions can be displayed
with the use of the A and v buttons:
Software revision level
IEEE address
Line frequency setting
Multiplexer status (on/off)
MX+B status (on/off)
MX+B values
dB reference value
Filter value (OO=filter disabled)
Zero status (on/off)
Zero value
Pressing the STATUS button a second time takes the in-
strument out of the status mode.
RESET-The RESET button is used to reset the instrument
back to the previously entered parameter. Keyed in
parameters are only entered after the ENTER button is
pressed. If RESET is pressed with the last parameter of a
program displayed, the program will be exited and the in-
strument will return to the previous operating state. This
button aborts back to normal operation when it is in one
of the following modes:
2-3
1. The data store is prompting for parameters (interval or
size).
2. The instrument is in the RECALL mode.
3. A front panel program has been selected (except Program
AC+DC which is treated as a normal measurement function (see STATUS).
Program RESET-Program RESET returns the instrument
to the factory default conditions. See paragraph 2.8.7 for
information on using this program.
DATA STORE-The DATA STORE button selects the 500
point data store mode of operation. Paragraph 2.7 contains
a complete description of data store operation. The secondary function of this button is to enter the number 9.
2.3.3 Input Terminals
The input terminals are intended to be used with safety
shrouded test leads to help minimize the possibility of contact with live circuits. Note that the terminals are duplicated
on the rear panel and that the INPUT switch determines
which set of terminals is active.
VOLTS OHMS HI and LO-The VOLTS OHMS HI and LO
terminals are used for making DC volts, AC volts and two-
wire resistance measurements.
AMPS and LO-The AMPS and LO terminals are used for
making DC current and AC current measurements.
RECALL-The RECALL button recalls and displays
readings stored in the data store. Paragraph 2.7.2 provides
a detailed procedure for recalling data. The secondary function of this button is to enter the number 8.
I’RGM-The PRGM button places the instrument in the
front panel program mode. Table 2-2 lists the available programs. Paragraph 2.8 contains descriptions and detailed
operating procedures for each front panel program.
LOCAL-When the instrument is in the IEEE-488 remote
state (REMmE indicator on), the LOCAL button will return
the instrument to front panel operation. However, if local
lockout (LLO) was asserted over the IEEE-488 bus, the
LOCAL button will be inoperative. See Section 3 for information on operating the instrument over the IEEE-488 bus.
Table 2-2. Front Panel Programs
AC+DC
L
TEMP
dB
ZERO
FILTER
RESET
4
90
91
92
93
94
95
96
Set RTD value and scale.
Low Frequency TRMS AC + DC.
Recall/modify dB reference value.
Recall/modify zero value.
Recall/modify number of readings averaged (filter value).
Reset internal conditions to factorv
default.
MX + B select.
save current front panel setup.
Recall/modify IEEE address.
Recall/modify line frequency setting
(50160Hz).
Self-test
Set values for MX + B program
Multiplexer on/off.
Digital calibration.
i
OHMS SENSE HI and LO-The OHMS SENSE HI and LO
terminals are used with the VOLTS OHMS HI and Lx) ter-
minals to make four-wire resistance measurements and
four-wire RTD temperature measurements.
2.3.4 Current Fuse
The current fuse protects the Model 1931 from input cur-
rent overloads. The instrument can handle UD to 2A continuously or 2.2A for less than one minute. l&fer to paragraph 6.3.2 for the current fuse replacement procedures.
2.4 REAR PANEL FAMILIARIZATION
The rear panel of the Model 193A is shown in Figure 2-2.
2.4.1 Connectors and Terminals
AC Receptacle-Power is applied through the supplied
power cord to the 3-terminal AC receptacle. Note that the
selected supply voltage is marked on the rear panel near
the connector.
Input Terminals-The rear panel input terminals perform
the same functions as the front panel input terminals.
Paragraph 2.3.3 contains the description of the input
terminals.
IEEE-488 Connector-This connector is used to connect the
instrument to the IEEE-488 bus. IEEE interface functions
are marked above the connector.
External Trigger Input-This BNC connector is used to ap-
ply pulses to trigger the Model 193A to take one or more
readings, depending on the selected trigger mode.
2-4
OPERATION
Voltmeter Complete Output-This BNC output connector
provides a pulse when the Model 193A has completed a
reading. It is useful for triggering other instrumentation.
2.4.2 Calibration Switch
Calibration of the Model 193A can only be done if the
calibration switch is in the unlock position.
2.4.3. Line Fuse
‘The line fuse provides protection for the AC power line
input. Refer to paragraph 6.3.1 for the tine fuse replacement
procedure.
2.5 ERROR AND WARNING DISPLAY
MESSAGES
Table 2-3 lists and explains
associated with incorrect front panel operation of the
193A. Also included is a warning
to the user that
sent on the input terminals.
hazardous voltages (4OV or more) are pre-
the
various display messages
message that
indicates
Model
2-512-6
CONTROL
OPERATION
0
Figure 2-1. Model 193A Front Panel
Figure 2-2. Model 193A Rear Panel
2-112-8
OPERATION
Table 2-3. Error and Warning Messages set to voltage range if the minimum voltage
spacing is reduced.
.....-“J’ -..y.“..“.*-..
NEED 1930
Selected option not installed.
NEED 1931
NEED 1930.1931
“H”
NO PROGRAM
1.VERFLO KOHM Overrange-Decimal point position
I(
TRIG-OVERRUN Trigger received while still pro-
CONFLICT Trying to calibrate with instru-
<OT ACV or ACA Selecting AC+DC or dB with in-
SHORT-PERIOD Instrument, as currently con-
High Voltage: 4OV or more on
input.
Invalid entry while trying to
select program.
and mnemonics define function
and range (Zkfl range shown).
The number of characters in the
“OVERFLO” message defines the
display resolution (6%d resolution shown).
cessmg reading from last trigger.
ment in an improper state.
strument not presently in ACV or
ACA.
figured, cannot run fast enough
to store readings at the selected
interval.
2.6 BASIC MEASUREMENTS
The following paragraphs describe the basic procedures for
making voltage, resistance, current, temperature, dB, and
AC + DC measurements. An ACV option must be installed for ACV measurements, the current option must be installed for DCA measurements and both options must be
installed for ACA and AAC + DC measurements.
When making measurements in high energy circuits use
test leads that meet the following requirements:
l Test leads should be fully insulated.
l Only use test leads that can be connected to the circuit
(e.g. alligator clips, spade lugs, etc.) for hands-off
measurements.
l Do not use test leads that decrease voltage spacing. This
diminishes arc protection and creates a hazardous
condition.
Use the following sequence when testing power circuits:
1. De-energize the circuit using the regular installed
connect-disconnect device such as the circuit breaker,
main switch, etc.
2. Attach the test leads to the circuit under test. Use appropriate safety rated leads for this application.
3. Set the DMM to the proper function and range.
4. Energize the circuit using the installed conncctdisconnect device and make measurements without
disconnecting the DMM.
5. De-energize the circuit using the installed connectdisconnect device.
6. Disconnect the test leads from the circuit under lest.
WARNING
The maximum common-mode input voltage
(the voltage between input LO and chassis
ground) Is 500V peak. Exceeding this value may
create a shock hazard.
2.6.1 Warm Up Period
High Energy Circuit Safety Precautions
To optimize safety when measuring voltage in high energy
distribution circuits, read and use the directions in the
following warning.
WARNING
Dangerous arcs of an explosive nature in a high
energy circuit can cause severe personal injury
or death. If the meter is connected to a high
energy circuit when set to a current range, low
resistance range or any other low impedance
range, the circuit is virtually shorted. Dangerous arcing can result even when the meter is
The Model 193A is usable immediately when it is first turn-
ed on. However, the instrument must be allowed to warm
up for at least one hour to achieve rated accuracy.
2.6.2
The zero feature sewes as a means of baseline suppression
by allowing a stored offset value to be subtracted from
subsequent readings. When the ZERO button is
the instrument takes the currently displayed rea mg as a
baseline value. All subsequent readings represent the differences between the applied signal level and the stored
baseline.
Zero
rewed,
R
2-9
OPERATION
A baseline level can be established for any or all measurement functions and is remembered by each function. For
example, a XIV baseline can be established on DCV, a 5V
baseline can be established on ACV and a 1OkQ baseline
can be established on OHMS. These levels will not be
cancelled by switchin back and forth between functions.
Once a baseline is esta hshed for a measurement function, %,
that stored level will be the same regardless of what range
the Model 193A is on. For example, if 1V is established as
the baseline on the 2V range, then the baseline will also
be 1V on the 2OV through 1OOOV ranges. A zero baseline
level can be as large as full range.
NOTE
The following discussion on dynamic range is
based on a display resolution of 6% digits. At 5%
digit resolution, the number of counts would be
reduced by a factor of 10. At 4%d resolution, counts
would be reduced by a factor of 100 and 3%d resolution would reduce counts by a factor of 1000.
By design, the dynamic measurement range of the Model
193A, at 6% digit resolution, is 4400000 counts (excluding
the 1OOOVDC and 700VAC ran es). With zero disabled, the
displayed reading range of t e mstrument is +2200000
counts. With zero enabled, the Model 193A has the capability to display &IO0000 counts. This increased display range
ensures that the dynamic measurement range of the instrument is not reduced when using a zero baseline value. The
following two exam les will use the maximum allowable
zero values (+2200 00 counts and -2200000 counts) to CT
show that dynamic measurement range will not be re-
duced. It is important to note that the increased display
range does not increase the maximum allowable input level
to the instrument. For example, on the 2V range, the Model
193A will always overrange when more than +2.2V is connected to the input.
Example l-The instrument is set to the 2VDC range and
a maximum -2.2OOOOOV is established as the zero value.
When -2.2OOOOOV is connected to the in ut of the Model
193A. the disolav will read O.OOOOOOV.
is connected &I tGe input, the display will read +4.4OOOOOV.
Thus, the dynamic measurement range of the Model 193A
is OV to 4.4V, which is 4400000 counts.
Example Z-The instrument is still set to the 2VDC range,
but a maximum +2.2OOOOOV is the zero level. When
+2.2OOOOOV is connected to the input of the Model 193A,
the display will read O.OOOOOOV. When -2.2OOOOOV is connected to the input, the display will read -4.4COOOOV. Thus
the d
namic measurement range of the instrument is -4.4V
9 to 0
, which is still 4400000 counts.
%
&en +2.2ooooov
Zen, Correction-The Model 193A must be properly zeroed
when using the 2OOmV DC or the 2003 range in order to
achieve rated accuracy specifications. To use ZERO for zero
correction, perform the following steps:
1. Disable zero, if
button. The Z
2.
Select the 2OOmV DC or the 2000 range.
3. Connect the test leads to the input of the Model 193A
and short them together. If four-wire resistance
measurements are to be made, connect and short all four
leads together.
Note: At 5% and 6% digit resolution, low measurement
techniques need to be employed. Use Kelvin test leads
or shielded test leads. See paragraph 2.6.5 for low level
measurement considerations.
4. Press the ZERO button. The display will read zero.
5.
Remove the short and connect the test leads to the signal
or resistance to be measured.
Note: Test lead resistance is also compensated for when
zeroing the 2000 range with the above procedure.
Baseline Levels-Baseline values can be established by
either applying baseline levels to the instrument or by setting baseline values with the front panel ZERO program.
Paragraph 2.8.5 contains the complete procedure for using
the ZERO program. To establish a baseline level by applying a level to the Model 193A, perform the following steps:
1. Disable zero, if presently enabled, by pressing the ZERO
button. The ZERO indicator will turn off.
2. Select a function and range that is appropriate for the
anticipated measurement.
3. Connect the desired baseline level to the in
Model 193A and note that level on the P
4. Press the ZERO button. The display will zero and the
ZERO indicator will be enabled. The previously
displayed reading will be the stored baseline. The zero
baseline value will also be stored in Program ZERO,
replacing the previous zero value.
resently enabled, by pressing the ZERO
IT
RO indicator will turn off.
ut of the
disp ay.
WARNING
If *4OV or more is present on the input terminals, the Model 193A will display the
mnemonic “H” to indicate the presence of
hazardous voltage. For example, the display
“OO.OOOOHVDC” indicates than k4OV or more
is present on the input.
5. Disconnect the stored signal from the input and connect
the signal to be measured in its place. Subsequent
readings will be the difference between the stored value
and the applied signal.
2-10
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