Keithley 195T User Manual
Model 195T
System Temperature DMM
Instruction Manual Supplement
Document Number: 195T-90%OIA
Publication Date: February 1993
.
WARRANTY
We warrant each of our products to be free from defects in material
and workmanship. Our obligation under this warranty is to repair
or replace any instrument or part thereof which, within a year after
shipment, proves defective upcn examination. We will pay local
domestic surface freight costs.
To exercise this warranty, write or call your local Keithley repre-
sentative, or contact Keithley headquarters in Cleveland, Ohio.
You will be given prompt assistance and shipping instructions.
REPAIRS AND
CALIBRATION
Keithley Instruments maintains a complete repair and calibration
service as well as a standards laboratory in Cleveland, Ohio.
A Keithley service facility at our Munich, Germany office is
available for our customers throughout Europe. Service in the
United Kingdom can be handled at our office in Reading. Additionally, Keithley representatives in most countries maintain service
and calibration facilities.
To insure prompt repair or recalibration service, please contact
your local field representative or Keithley headquarters directly
before returning the instrument. Estimates for repairs, normal
recalibrations and calibrations traceable to the National Bureau of
Standards are available upon request.
Keithley Instruments, Inc.128775 Aurora Road/Cleveland, Ohio 44139/U.S.A./(216) 246-0400/Telex: 965469
WEST GERMANY: Ksithley Instruments GmbHlHeiglhofstrasse 5/O-8000 MUnchen 7O/lO691 7144&65/Telex: 521 21 60
GREAT BRITAIN: Keithley Instruments. Ltd./l, Boulton Road/Reading, Berkshire RG2 ONL/i07341 66 12 B7lTelex: 647047
FRANCE: Kefthley Instrumenta SAALl2 Bis, Rue Ldon Blum1B.P. 60/91121 Palaiseau Cedex/~61011.51.55/Telex: 600933F
NETHERLANDS: Keithley Instrument8 BVlArkelsedijk 4/NL-4206 AC Gorinchem/i016301 25577/T&x: 24 664
SWITZERLAND: Kelthley Instruments SAIKriasbachstr. 4/CH-6600 OUbendorf/Ol 621 94 44/T&x: 57 536
AUSTRIA: Kslthley instruments Ges.m.b.H./OOblinger Hauptstr. 32/A-1190 Wien/0222 314 2BS/Telex: 13 45 00
Model 195T
System Temperature DMM
Instruction Manual Supplement
01983, Keithley Instruments, Inc.
Cleveland, Ohio, U.S.A.
SPECIFICATIONS
RTD TYPE: lOO* platinum; DIN 43 760 or IPTS-SB, Programmable alpha
and delta, 3. or 4.wire.
MAXIMUM LEAD REBlBTANCE leach lead): 4.wire: 250.
SENSOR CURRENT: l.OmA maximum. RMS.
BENCH READING RATE: 1.2 readings per second.
MAXIMUM COMMON MODE VOLTAGE: 500V 142V with Mod81 1951
connected,.
COMMON MODE REJECTION: ,Less than 0.005°C/volt at DC, 50Hz
and 60Hz (1000 unbalance, LO drivenl.
MAXIMUM ALLOWABLE INPUT: 360V peak. 250V rms.
ACCESSORIES SUPPLIED: Model 1951’ lnp~t Adapter. Model 9693
General Purpose/Immersion Probe l4wire).
ACCESSORIES AVAILABLE:
Model 1961 Input Adapter
Model 8991 Connector Kit (enables connecting to 3. or 4.wire RTDs)
Model 9993 Gensral Purpose/Immersion Probe ICwirel
Model 9695 Surface Probe kvirel
Model 9696 Air/Gas Probe ICwirel
S-wire: 150.
TABLE OF CONTENTS
Paragraph
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.9.1
1.9.2
1 Al.3
1.9.4
1.9.5
2.1
2.2
2.3
2.4
2.4.1
2.4.2
2.5
2.6
3.1
3.2
3.3
3.4
3.5
4.1
4.2
4.3
4.4
5.1
5.2
5.2.1
5.2.2
5.2.3
5.2.4
5.2.5
5.3
5.3.1
5.3.2
5.4
5.5
Title
SECTION 1 GENERAL INFORMATION
Introduction .....................................................................
Modell95TFeatures ..............................................................
Warranty Information.
.............................................................
ManualAddenda .................................................................
Safety Terms and Symbols
..................
......................................
PalIe
l-l
l-l
1-l
1-l
l-l
Specifications .................................................................... l-l
Unpackingandlnspection
..........................................................
Scope of Model 195T Instruction Manual
.............................................
l-l
l-l
Accessories ...................................................................... l-2
Model 195T Input Adapter Box.
...................................................
Model669lConnectorKit ........................................................
Model 8693 General Purpose Immersion Probe.
......................................
Modal6695SurfaceProbe .......................................................
Model 6696 Air/Gas Probe
SECTION 2 OPERATION
.......................................................
l-2
1-2
1.2
1-2
l-2
Introduction ..................................................................... 2-l
ProbeConnection .................................................................
Temperature Measurement Procedure.
IEEE Bus Control of Temperature Measurements
IEEE Temperature Commands.
IEEE Bus Temperature Data Format
3-Wire Sensor Operation
..........................................................
...............................................
.......................................
....................................................
................................................
2-1
2-l
2.2
2-2
2-2
2-3
Calibrationstandards .............................................................. 2-3
SECTION 3 PERFORMANCE VERIFICATION
Introduction
Environmental Conditions
RecommendedEquipment
Initial Conditions
Verification Procedure
SECTION 4 THEORY OF OPERATION
..................................................................
..........................................................
.........................................................
..................................................................
.............................................................
Introduction .....................................................................
RTD Resistance Measurement
......................................................
:. 3-l
3-l
3-l
3-l
3-l
4-l
4-l
FETSwitching Sequence ........................................................... 4-l
ReadingCalculations.. ............................................................
SECTION 5 SERVICING INFORMATION
Introduction .....................................................................
Canbra6on .......................................................................
Environmental Conditions
........................................................
Warm-UpPeriod ................................................................
Calibration Constants.
Front Panel Calibration Prqcedure.
Temperature Calibration Over the IEEE-466 Bus
...........................................................
.................................................
...................................... 5-2
ReplaceableParts .................................................................
Ordering Information
Parts List
......................................................................
Troubleshooting Information
Component Layouts and Schematics.
............................................................
........................................................
................................................
4-l
5-l
5-l
5-l
5-l
5-1
5-l
5-2
5-2
5-3
5-3
5-3
LIST OF FIGURES
Figure
2-l Model 195T Front Panel Showing Model 1951 Input Adapter Box
2-2
2-3
3-1
4-l
4-2
4-3
5-1
5-2
5-3
Model195TProbeWiring
3-Wire Sensor Connections.
Connections for Performance Verification
Simplified Circuit of RTD Resistance Measurement
FETSwitchingSequence
FET Switching Sequence for RTD Resistance Measurements
Remote Box, Schematic Diagram, Drawing Number 1951-106
Mother Board, Component Layout, Drawing Number 195T-100
Mother Board. Schematic Diagram, Drawing Number 195T-106
..........................................................
........................................................ 2-3
..........................................................
Title
.............................................
.....................................
.............................
............................
...........................
................... : ...... 5-9
LIST OF TABLES
Table Title
2-1 Calibration Standards.,
3-1 Performance Verification Summary
5-1
5-2
Calibration Procedure Messages,
Model 195T Replaceable Parts List
............................................................
..................................................
.................................................... 5-1
...................................................
Page
........................ 2-l
2-l
3-1
41
4-1
4-2
5-4
5-5
Page
2-3
3-1
5-3
SECTION 1
GENERAL INFORMATION
1.1 INTRODUCTION
The Model 195T is an enhanced version of the Model 195 that
includes temperature measuring capabilities. The Model 195T
is capable of temperature measurements in the range of
-220°C and +630°C and between -360°F and +llOO°F.
The instrument is designed to work with platinum RTD
probes, a factor which contributes to high accuracy. Temperature readings may be read directly from the front panel
display or transmitted over the IEEE bus to a central controller
or other instrumentation.
1.2 MODEL 195T FEATURES
Some kev Model 195T features include:
High Accuracy. Because platinum RTD probes have
1.
predictable resistance change with temperature and are
highly linear, temperature measurements are made with a
greater degree of accuracy than is possible with thermistor or thermocouple type probes.
Ease of Use. The temperature measuring mods is easily
2.
entered from the front panel or over the IEEE bus. Sophis-
ticated software automatically measures the probe
resistance and calculates the reading.
3.
Dual Scale Temperature Measurements. Temperature
readout may be obtained in either OC or OF. Readings are
available on the display and over the IEEE bus.
Front Panel Calibration. Temperature calibration may be
4.
performed from the front panel. Probe errors can be
minimized with the calibration procedure.
Four Wire Resistance Measurements. Resistance msas-
5.
urements with the supplied probe are performed using the
4-wire method to minimize the effects of lead resistance.
6.
Selectable 3-wire or 4.wire Operation. The instrument
may be used with either 3-wire or 4-wire probes; the mods
of operation is easily changed from the front panel.
1.3 WARRANTY INFORMATION
Warranty information may be found inside the front cover of
this manual. Should it become necessary to use the warranTV, contact Your nearest Keithley representative or the factory
to determine the correct course of action. Keithlsy Instruments, Inc. maintains service facilities in the United States,
West Germany, Great Britain, France, the Netherlands, Switzerland and Austria. Information regarding the application,
operation, or service of Your instrument may be directed to
the applications engineer at any of these locations. Check inside the front covsr of this manual for addresses.
1.4 MANUAL ADDENDA
Information pertaining to improvements or changes to the in-
strument which occur after the printing of this manual will be
found on an addendum sheet included with the unit. Be sure
to note any changes before attempting to operate or service
the instrument.
1.5 SAFETY TERMS AND SYMBOLS
The following safety terms are used in this manual or found
on the instrument:
The&symbol on the instrument indicates that a poten-
tial of 1OOOV or more may be present on the terminal(s).
The A symbol on the instrument indicates that the user
should refer to the operating instructions.
The WARNING heading used in this manual explains
dangers that could result in personal injury or death.
The CAUTION heading used in this manual explains hazards
that could damage the instrument.
1.6 SPECIFICATIONS
Detailed specifications pertaining to Model 195T temperature
measurements are located at the front of this manual.All
other specifications are located at the front of the Model 195
Instruction Manual.
1.7 UNPACKING AND INSPECTION
The Model 195T was carefully inspected before shipment.
Upon receiving the unit, carefully unpack all items from the
shipping carton and check for any obvious signs of physical
damage. Report any damage to the shipping agent at once.
Retain the original packing materials in case reshipment
becomes necessary.
The following items are included with every Model 195T shipment:
-Model 195T System Temperature DMM
*Model 1951 Input Adapter Box
*Model 8693 General Purpose Immersion Probe (Cwire
platinum RTD, DIN 43 760 standard)
*Model 195 Instruction Manual
*Model 195T Instruction Manual Supplement
1.8 SCOPE OF MODEL 195T INSTRUCTION MANUAL
This manual provides information pertaining to Model 195T
temperature measuring capabilities and is supplied as a supplement to the Model 195 Instruction Manual, which contains
information on all other operating aspects of the instrument.
The Model 195T manual is divided into the following sections:
1. Section 2 contains information necessary to connect
temperature probes and program the Model 195T to make
temperature measurements. Additional IEEE bus commands are also included in this section.
l-l
2. Procedures necessary for checking temperature measuring
accuracy are contained in Section 3.
3. Basic theory of operation may be found in Section 4.
4. Servicing information, including calibration, and a list of
replaceable parts is located in Section 5.
1.9 ACCESSORIES
1.9.3 Modal 8693 General Purpose Immersion Probe
The Model 8693 (supplied with the Model 195Tl is a general
purpose probe designed for immersion in liquids as well as
other general purpose applications. The Model 8693
measures between -22OOC and +630°C and has a basic
.tolerance of f0.3OC at 0%.
Accessories available for the Model 195T are listed below. All
probes are of 4-wire platinum RTD configuration and con-
form to the DIN 43 760 standard.
1.9.1 Model 1951 Input Adapter Box
The Model 1951 (supplied with the Model 195Tj provides a
means of interfacing probes terminated with a 4-wire instrumentation connector to the banana jacks on the instrument.
1.9.2 Model 9691 Connector Kit
The Model 8691 Connector Kit contains a male 4-wire con-
nector, a female 4-wire connector with attached coiled cable
(mates with connector on Model 1951). and male and female
3-wire adapters.
1.9.4 Modal 8695 Surface Probe
The Model 8695 probe is designed to measure the flat surfaces of solids in the range of -5OOC to +260°C. The Model
8695 has a basic tolerance of f0.3Y at 0%.
1.9.5 Modal 8696 Air/Gas Probe
The Model 8696 probe has an exposed junction within a protective shroud. The measurement range of the Model 8696 is
between -50°C and + 260°C; the probe has a basic tolerance
of *0.3°C at OOC.
1-2
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