Keithley 2001-TCSCAN Service manual
Model 2001-TCSCAN
Scanner Card
Instruction Manual
Contains Operating and Servicing Information
W ARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from
date of shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation.
During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithle y representative, or contact Keithle y headquarters in Cleveland, Ohio. Y ou
will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility.
Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance
of the original warranty period, or at least 90 days.
LIMIT A TION OF W ARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse
of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN
ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS
OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PR OPERTY.
Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: 440-248-6168 • http://www.keithle y.com
CHINA: Keithley Instruments China • Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-62022886 • Fax: 8610-62022892
FRANCE: Keithley Instruments SARL • BP 60 • 3 Allée des Garays • 91122 Palaiseau Cédex • 33-1-60-11-51-55 • Fax: 33-1-60-11-77-26
GERMANY: Keithley Instruments GmbH • Landsberger Strasse 65 • D-82110 Germering, Munich • 49-89-8493070 • Fax: 49-89-84930759
GREAT BRITAIN: Keithley Instruments, Ltd. • The Minster • 58 Portman Road • Reading, Berkshire, England RG3 1EA • 44-1189-596469 • Fax: 44-1189-575666
ITALY: Keithley Instruments SRL • Viale S. Gimignano 38 • 20146 Milano • 39-2-48303008 • Fax: 39-2-48302274
NETHERLANDS: Keithley Instruments BV • Avelingen West 49 • 4202 MS Gorinchem • 31-(0)183-635333 • Fax: 31-(0)183-630821
SWITZERLAND: Keithley Instruments SA • Kriesbachstrasse 4 • 8600 Dübendorf • 41-1-8219444 • Fax: 41-1-8203081
TAIWAN: Keithley Instruments Taiwan • 1FL., 85 Po Ai Street • Hsinchu, Taiwan • 886-3-572-9077 • Fax: 886-3-572-9031
1/99
Model 2001-TCSCAN
Instruction Manual
©1993, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Second Printing, January 1997
Document Number: 2001-TCSC-901-01 Rev. B
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The
Revision Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are
released between Revisions, contain important change information that the user should incorporate immediately
into the manual. Addenda are numbered sequentially. When a new Revision is created, all Addenda associated
with the previous Revision of the manual are incorporated into the new Revision of the manual. Each new Revision includes a revised copy of this print history page.
Revision A (Document Number 2001-TCSC-901-01).................................................................... March 1993
Addendum A (Document Number 2001-TCSC-901-02) .......................................................November 1995
Revision B (Document Number 2001-TCSC-901-01) ................................................................. January 1997
All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.
Safety Precautions
The following safety precautions should be observed before using
this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions
may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read the operating information
carefully before using the product.
The types of product users are:
Responsible body is the individual or group responsible for the use
and maintenance of equipment, for ensuring that the equipment is
operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be
trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with
hazardous live circuits.
Maintenance personnel perform routine procedures on the product
to keep it operating, for example, setting the line voltage or replacing consumable materials. Maintenance procedures are described in
the manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by service
personnel.
Service personnel are trained to work on live circuits, and perform
safe installations and repairs of products. Only properly trained service personnel may perform installation and service procedures.
Users of this product must be protected from electric shock at all
times. The responsible body must ensure that users are prevented
access and/or insulated from every connection point. In some cases,
connections must be exposed to potential human contact. Product
users in these circumstances must be trained to protect themselves
from the risk of electric shock. If the circuit is capable of operating
at or above 1000 volts, no conductive part of the circuit may be
exposed.
As described in the International Electrotechnical Commission
(IEC) Standard IEC 664, digital multimeter measuring circuits
(e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are
Installation Category II. All other instruments’ signal terminals are
Installation Category I and must not be connected to mains.
Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting
cables, test leads, and jumpers for possible wear, cracks, or breaks
before each use.
For maximum safety, do not touch the product, test cables, or any
other instruments while power is applied to the circuit under test.
ALWAYS remove power from the entire test system and discharge
any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal
changes, such as installing or removing jumpers.
Exercise extreme caution when a shock hazard is present. Lethal
voltage may be present on cable connector jacks or test fixtures. The
American National Standards Institute (ANSI) states that a shock
hazard exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present. A good safety practice is to expect
that hazardous voltage is present in any unknown circuit bef ore
measuring.
Do not touch any object that could provide a current path to the
common side of the circuit under test or power line (earth) ground.
Always make measurements with dry hands while standing on a
dry, insulated surface capable of withstanding the voltage being
measured.
The instrument and accessories must be used in accordance with its
specifications and operating instructions or the safety of the equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or
switching card.
When fuses are used in a product, replace with same type and rating
for continued protection against fire hazard.
Chassis connections must only be used as shield connections for
measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a
lid interlock.
If a screw is present, connect it to safety earth ground using the
wire recommended in the user documentation.
!
The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.
The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of normal
and common mode voltages. Use standard safety precautions to
avoid personal contact with these voltages.
The WARNING heading in a manual explains dangers that might
result in personal injury or death. Alw ays read the associated infor mation very carefully before performing the indicated procedure.
The CAUTION heading in a manual explains hazards that could
damage the instrument. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and
all test cables.
To maintain protection from electric shock and fire, replacement
components in mains circuits, including the power transformer, test
leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals,
may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as
long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments
to maintain accuracy and functionality of the product.) If you are
unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.
To clean an instrument, use a damp cloth or mild, water based
cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill
on the instrument. Products that consist of a circuit board with no
case or chassis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected, the board should be returned to the factory for proper
cleaning/servicing.
Rev. 2/99
2001-TCSCAN THERMOC OUPLE/GENERAL PURPOSE SCANNER CARD
SPECIFICA TIONS
Thermocouple Accuracy
Total Absolute Error
1 Year
Thermocouple Default 0°–18°C &
Type Range Resolution 18°–28°C28°–50°C
J –100 to 760°C 0.1°C ±0.65°C ±1.08°C
K –100 to 1372°C 0.1°C ±0.70 °C ±1.32°C
T –100 to 400°C 0.1°C ±0.68°C ±1.22°C
E –100 to 1000°C 0.1°C ±0.67°C ±1.11°C
R 0 to 1768°C 1.0°C ±1.31°C ±3.06°C
S 0 to 1768°C 1.0°C ±1.30°C ±3.02°C
B 350 to 1820°C 1.0°C ±1.65°C ±4.14°C
1
When used with Model 2001 Multimeter.
Specifications apply to channels 2–6. Add 0.06°C for each adjacent channel
away from channel 6.
Extended range (Types J, K, T, E): -200. 0°C to -100. 1°C add ±0.1°C.
Excluding thermocouple error.
1
Ordering Information
2001-TCSCAN 9 Channel Thermocouple/General Purpose Scanner
2001 High Performance 7
2001/MEM1 Base 2001 plus additional memory. Store up to 6000 readings
2001/MEM2 Base 2001 plus additional memory. Store up to 30000 readings
7401 Type K Thermocouple Wire Kit (100 ft)
8530 Centronics Printer Adapter
8681 Miniature Surface RTD Probe
Specifications subject to change without notice.
1
⁄2-Digit Multimeter
Specifications
GENERAL: 9 channels of 2-pole analog input, 1 cold junction sensor.
FUNCTIONS: DCV, ACV, 4-wire Ω, Thermocouple, 2-wire Ω, 4-wire RTD, 2-
wire RTD, Frequency (can be mixed from channel to channel).
THERMOCOUPLE SCAN SPEED: 25 channels/second @ 0.1°C resolution;
43 channels/second @ 1°C resolution.
CAPABILITIES: Multiplex one of nine 2-pole or one of four 4-pole analog
signals into Model 2001 DMM and/or any combination of 2- or 4-pole
analog signals.
REFERENCE OUTPUT: +200µV/°C (+54.63mV at 0°C).
ALL INPUTS
Maximum Signal Levels
DC: 110V DC, <1A switched, 30VA maximum (resistive load).
AC: 125V AC rms or 175V AC peak, 1A switched, 62.5VA maximum
(resistive load).
Contact Life: >10
cold switching.
Contact Resistance
Actuation Time: 2.5ms maximum on/off.
Contact Potential
Connector Type: Screw terminal, #22 AWG wire size (0.062 O.D.).
Isolation Between Any Two Terminals: >10
Common Mode Voltage: 350V peak between any terminal and earth.
Maximum Voltage Between Any Two Terminals: 110VDC, 125VAC RMS.
DIMENSIONS, WEIGHT: 21mm high × 72mm wide × 221mm deep (0.83 in ×
2.83 in × 8.7 in). Net weight 283g (10 oz).
2
Channels 5 and 10 maximum power = 0.25 VA maximum (factory installed
120Ω, 5%, 1/4W resistors. User may replace with jumper. See note in manual
for complete instructions.)
3
Channels 5 and 10 contact potential = ±1µV typical, 2µV max.
2
:
5
operations at maximum signal level; >108 operations
2
: <1Ω at end of contact life.
3
: <±500nV typical per contact, 1µV max.
9
, <75pF.
Channel 1
(Reference
Junction)
Channel 2-4
Channel 5
Channel 6
Channel 7-9
Channel 10
HI
LO
HI
LO
HI
LO
HI
OUT A (To Model 2001
input jacks)
LO
HI
OUT B (To Model 2001
sense jacks)
LO
2-Pole4-Pole
Table of Contents
1 General Information
1.1 Introduction......................................................................................................................................................... 1-1
1.2 Features............................................................................................................................................................... 1-1
1.3 Warranty information.......................................................................................................................................... 1-1
1.4 Manual addenda.................................................................................................................................................. 1-2
1.5 Safety symbols and terms ................................................................................................................................... 1-2
1.6 Specifications...................................................................................................................................................... 1-2
1.7 Unpacking and inspection................................................................................................................................... 1-2
1.7.1 Inspection for damage................................................................................................................................. 1-2
1.7.2 Handling precautions .................................................................................................................................. 1-2
1.7.3 Shipment contents....................................................................................................................................... 1-2
1.7.4 Instruction manual....................................................................................................................................... 1-2
1.8 Repacking for shipment ...................................................................................................................................... 1-3
1.9 Optional accessories............................................................................................................................................ 1-3
2 Card Connections and Installation
2.1 Introduction......................................................................................................................................................... 2-1
2.2 Handling precautions .......................................................................................................................................... 2-1
2.3 Connections......................................................................................................................................................... 2-1
2.3.1 Card configuration ...................................................................................................................................... 2-2
2.3.2 Card connectors........................................................................................................................................... 2-3
2.3.3 Wiring procedure ........................................................................................................................................ 2-3
2.3.4 Output connections ..................................................................................................................................... 2-4
2.3.5 Dressing leads ............................................................................................................................................. 2-4
2.4 Typical connecting schemes ............................................................................................................................... 2-6
2.4.1 Thermocouple connections ......................................................................................................................... 2-6
2.4.2 Voltage connections.................................................................................................................................... 2-7
2.4.3 Resistance connections ............................................................................................................................... 2-8
2.5 Card installation and removal ........................................................................................................................... 2-10
2.5.1 Scanner card installation........................................................................................................................... 2-10
2.5.2 Output connections to multimeter............................................................................................................. 2-12
2.5.3 Scanner card removal................................................................................................................................ 2-12
i
3 Operation
3.1 Introduction ......................................................................................................................................................... 3-1
3.2 Signal limitations................................................................................................................................................. 3-2
3.3 Scanner card detection......................................................................................................................................... 3-2
3.3.1 Power-up detection...................................................................................................................................... 3-2
3.3.2 Scanner option bus query ............................................................................................................................ 3-2
3.4 Front panel scanner controls................................................................................................................................ 3-2
3.4.1 Open and close channels (CHAN) .............................................................................................................. 3-2
3.4.2 Configure channels (CONFIG-CHAN)....................................................................................................... 3-4
3.4.3 Scan configuration (CONFIG-SCAN) ........................................................................................................ 3-5
3.4.4 Using SCAN to configure scan parameters and start scanning................................................................... 3-5
3.4.5 Using EXIT to stop scanning ...................................................................................................................... 3-6
3.4.6 Manual scanning.......................................................................................................................................... 3-6
3.5 IEEE-488 bus scanner commands............................................................................................................... 3-6
3.6 Closing and opening channels............................................................................................................................. 3-9
3.6.1 Closing channels.......................................................................................................................................... 3-9
3.6.2 Opening channels ........................................................................................................................................ 3-9
3.7 Scanning channels............................................................................................................................................... 3-9
3.7.1 Front panel scanning.................................................................................................................................... 3-9
3.7.2 IEEE-488 bus scanning ............................................................................................................................. 3-10
3.8 Temperature measurements............................................................................................................................... 3-11
3.8.1 Thermocouple temperature measurements................................................................................................ 3-11
3.8.2 RTD temperature measurements............................................................................................................... 3-13
3.8.3 Using RTD and thermocouple sensors together........................................................................................ 3-14
3.8.4 IEEE-488 programming example (temperature measurements)............................................................... 3-15
3.9 Basic front panel operation................................................................................................................................ 3-18
3.9.1 Configure stepping and scanning .............................................................................................................. 3-18
3.9.2 Open and close channels ............................................................................................................................3-19
3.9.3 Start stepping or scanning ..........................................................................................................................3-20
3.10 Temperature measurements............................................................................................................................... 3-20
3.10.1 Temperature measurement configuration...................................................................................................3-21
3.10.2 Temperature measurement procedure ........................................................................................................3-21
3.11 Remote operation............................................................................................................................................... 3-21
3.11.1 IEEE-488 programming example (temperature measurements)................................................................3-23
3.12 Typical applications........................................................................................................................................... 3-25
3.12.1 Resistor testing .......................................................................................................................................... 3-25
3.12.2 Resistor temperature coefficient testing.................................................................................................... 3-28
3.13 Measurement considerations ............................................................................................................................. 3-30
3.13.1 Thermocouple measurement error sources................................................................................................ 3-30
3.13.2 Path isolation............................................................................................................................................. 3-31
3.13.3 Channel resistance..................................................................................................................................... 3-31
3.13.4 Magnetic fields.......................................................................................................................................... 3-31
3.13.5 Electromagnetic Interference (EMI).......................................................................................................... 3-32
3.13.6 Ground loops............................................................................................................................................. 3-32
3.13.7 Keeping connectors clean.......................................................................................................................... 3-33
ii
4 Service Information
4.1 Introduction......................................................................................................................................................... 4-1
4.2 Handling and cleaning precautions..................................................................................................................... 4-1
4.2.1 Handling precautions .................................................................................................................................. 4-1
4.2.2 Soldering precautions.................................................................................................................................. 4-2
4.3 Performance verification..................................................................................................................................... 4-2
4.3.1 Environmental conditions ........................................................................................................................... 4-2
4.3.2 Recommended equipment........................................................................................................................... 4-2
4.3.3 Scanner card connections............................................................................................................................ 4-2
4.3.4 Reference junction test................................................................................................................................ 4-2
4.3.5 Path resistance tests..................................................................................................................................... 4-4
4.3.6 Contact potential tests................................................................................................................................. 4-5
4.3.7 Isolation tests............................................................................................................................................... 4-8
4.4 Calibration......................................................................................................................................................... 4-10
4.4.1 Calibration with thermistor probe............................................................................................................. 4-10
4.4.2 Calibration with thermocouple wire ......................................................................................................... 4-11
4.5 Special handling of static-sensitive devices...................................................................................................... 4-13
4.6 Principles of operation ...................................................................................................................................... 4-13
4.6.1 Block diagram........................................................................................................................................... 4-13
4.6.2 Relay control............................................................................................................................................. 4-14
4.6.3 Switching circuits...................................................................................................................................... 4-14
4.6.4 Power-on safeguard................................................................................................................................... 4-14
4.6.5 Reference junction .................................................................................................................................... 4-14
4.7 Troubleshooting ................................................................................................................................................ 4-14
4.7.1 Troubleshooting equipment ...................................................................................................................... 4-14
4.7.2 Troubleshooting access............................................................................................................................. 4-14
4.7.3 Troubleshooting procedure ....................................................................................................................... 4-15
4.8 Scanner card modification ................................................................................................................................ 4-15
5 Replaceable Parts
5.1 Introduction......................................................................................................................................................... 5-1
5.2 Parts lists ............................................................................................................................................................. 5-1
5.3 Ordering information .......................................................................................................................................... 5-1
5.4 Factory service.................................................................................................................................................... 5-1
5.5 Component layout and schematic diagram......................................................................................................... 5-1
A Thermocouple Basics
A.1 Definitions.......................................................................................................................................................... A-1
A.2 Theory ................................................................................................................................................................ A-1
A.3 Measurement procedure..................................................................................................................................... A-2
A.4 Measuring example............................................................................................................................................ A-2
B Thermocouple Conversion Tables
iii
List of Illustrations
2 Card Connections and Installation
Figure 2-1 Model 2001-TCSCAN simplified schematic ............................................................................................. 2-2
Figure 2-2 Card connectors.......................................................................................................................................... 2-3
Figure 2-3 Output connections..................................................................................................................................... 2-5
Figure 2-4 Routing wires through cable clamp............................................................................................................ 2-5
Figure 2-5 Typical connections for thermocouple scanning........................................................................................ 2-6
Figure 2-6 Connections for voltage scanning .............................................................................................................. 2-7
Figure 2-7 Typical connections for 2-wire resistance scanning .................................................................................. 2-8
Figure 2-8 Typical connections for 4-wire resistance scanning .................................................................................. 2-9
Figure 2-9 Card installation ....................................................................................................................................... 2-11
Figure 2-10 2-pole output connections ........................................................................................................................ 2-13
Figure 2-11 4-pole output connections ........................................................................................................................ 2-14
3 Operation
Figure 3-1 Models 2001 and 2002 front panel scanner controls.................................................................................. 3-3
Figure 3-2 Models 2000 and 2010 front panel scanner controls ............................................................................... 3-18
Figure 3-3 2-wire resistance test connections............................................................................................................ 3-25
Figure 3-4 4-wire resistance test connections............................................................................................................ 3-26
Figure 3-5 Combining 2-pole and 4-pole switching .................................................................................................. 3-27
Figure 3-6 Resistor temperature coefficient testing................................................................................................... 3-29
Figure 3-7 Path isolation resistance ........................................................................................................................... 3-31
Figure 3-8 Voltage attenuation by path isolation resistance...................................................................................... 3-31
Figure 3-9 Power line ground loops........................................................................................................................... 3-32
Figure 3-10 Eliminating ground loops......................................................................................................................... 3-32
v
4 Service Information
Figure 4-1 Connections for reference junction test...................................................................................................... 4-4
Figure 4-2 Connections for path resistance checks...................................................................................................... 4-6
Figure 4-3 Connections for contact potential tests....................................................................................................... 4-7
Figure 4-4 Connections for same-channel isolation tests............................................................................................. 4-9
Figure 4-5 Connections for channel-to-channel isolation tests.................................................................................... 4-9
Figure 4-6 Connections for HI and LO terminal to chassis ground isolation tests .................................................... 4-10
Figure 4-7 Calibration with thermistor probe............................................................................................................. 4-12
Figure 4-8 Calibration with thermocouple wire......................................................................................................... 4-13
Figure 4-9 Block diagram........................................................................................................................................... 4-14
Figure 4-10 Current-limiting resistor locations ........................................................................................................... 4-16
A Thermocouple Basics
Figure A-1 Thermocouple measurement...................................................................................................................... A-1
vi
List of Tables
3 Operation
Table 3-1 Summary of SCPI commands (Models 2001 and 2002) ........................................................................... 3-7
Table 3-2 Summary of SCPI commands (Models 2000 and 2010).......................................................................... 3-22
Table 3-3 Additional SCPI commands for the Model 2010..................................................................................... 3-23
4 Service Information
Table 4-1 Verification and calibration equipment ..................................................................................................... 4-3
Table 4-2 Recommended troubleshooting equipment ............................................................................................. 4-14
Table 4-3 Troubleshooting procedure ...................................................................................................................... 4-16
5 Replaceable Parts
Table 5-1 Electrical parts ........................................................................................................................................... 5-2
Table 5-2 Mechanical parts ........................................................................................................................................ 5-3
B Thermocouple Conversion Tables
Table B-1 NIST Quartic Coefficients for Types, S, R, B, E, J, K, and T .................................................................. B-2
vii
1
General Information
1.1 Introduction
This section contains general information about the Model
2001-TCSCAN General Purpose/Thermocouple Scanner
Card, which is designed to be used with the Model 2000,
2001, 2002, and 2010 DMMs to make accurate multi-channel
thermocouple measurements. The DMMs will automatically
convert type J, K, T, E, R, S, and B thermocouple voltages to
Celsius, Fahrenheit, or Kelvin temperature readings.
The Model 2001-TCSCAN can also be used for a variety of
nine-channel, mixed-signal switching applications. The
500nV-125V signal voltage range of the Model 2001TCSCAN makes it well suited for both low and high signal
levels.
Section 1 is arranged in the following manner:
1.2 Features
1.3 Warranty information
1.4 Manual addenda
1.5 Safety symbols and terms
1.6 Specifications
1.7 Unpacking and inspection
1.2 Features
The Model 2001-TCSCAN is a scanner card designed to be
installed in the Model 2000, 2001, 2002, or 2010 Multimeter.
Key features include:
• Built-in reference junction (channel 1).
• Low contact potential and offset current.
• Input connectors are in contact with an isothermal block
to minimize temperature differences.
• Nine channels of 2-pole relay input.
• Four channel pairs configurable for 4-pole operation.
• Multiplex one of nine 2-pole, or one of four 4-pole
channels into the DMM.
1.3 W arranty information
Warranty information is located on the inside front cover of
this instruction manual. Should your Model 2001-TCSCAN
require warranty service, contact the Keithley representative
or authorized repair facility in your area for further
information. When returning the scanner card for repair, be
sure to fill out and include the service form at the back of this
manual in order to provide the repair facility with the
necessary information.
1.8 Repacking for shipment
1.9 Optional accessories
1-1
General Information
1.4 Manual addenda
Any improvements or changes concerning the scanner card
or manual will be explained in an addendum included with
the card. Addenda are provided in a page replacement
format. Simply replace the obsolete pages with the new
pages.
1.5 Safety symbols and terms
The following symbols and terms may be found on an instrument or used in this manual.
!
The symbol on an instrument indicates that the user
should refer to the operating instructions located in the instruction manual.
The symbol an instrument shows that high voltage
may be present on the terminal(s). Use standard safety precautions to avoid personal contact with these voltages.
1.7 Unpacking and inspection
1.7.1 Inspection for damage
The Model 2001-TCSCAN is packaged in a re-sealable,
anti-static bag to protect it from damage due to static
discharge and from contamination that could degrade its
performance. Before removing the card from the bag,
observe the precautions below on handling.
1.7.2 Handling precautions
• Always grasp the card by the side edges and covers. Do
not touch the board surfaces or components.
• When the card is not installed in a DMM, keep the card
in the anti-static bag, and store it in the original packing
carton. After remo ving the card from its anti-static bag,
inspect it for any obvious signs of physical damage.
Report any such damage to the shipping agent
immediately.
The WARNING heading used in this manual explains dangers that might result in personal injury or death. Always
read the associated information very carefully before performing the indicated procedure.
The CAUTION heading used in this manual explains
hazards that could damage the scanner card. Such damage
may invalidate the warranty.
1.6 Specifications
Model 2001-TCSCAN specifications are found at the front
of this manual. All specifications e xcept temperature accuracy are exclusiv e of the DMM specifications. Temperature accuracy specifications include DMM temperature accuracy.
Note that Model 2001-TCSCAN scan temperature accuracy
is specified down to -100°C. For temperatures from -100.1°C
and -200°C using type J, K, T, or E thermocouples, add an
additional ±0.1°C of error.
1.7.3 Shipment contents
The following items are included with every Model 2001TCSCAN order:
• Model 2001-TCSCAN Scanner Card
• Model 2001-TCSCAN Instruction Manual
• CA-109 test lead set for output connections (two red,
two black)
• Additional accessories as ordered
1.7.4 Instruction manual
If an additional Model 2001-TCSCAN Instruction Manual is
required, order the manual package, Keithley part number
2001-TCSC-901-00. The manual package includes an
instruction manual and any pertinent addenda.
1-2
General Information
1.8 Repacking for shipment
Should it become necessary to return the Model 2001-TCSCAN
for repair, carefully pack the unit in its original packing carton or
the equivalent, and include the follo wing information:
• Advise as to the warranty status of the scanner card.
• Write ATTENTION REPAIR DEPARTMENT on the
shipping label.
• Fill out and include the service form located at the back
of this manual.
1.9 Optional accessories
Model 7401 — The Model 7401 is a thermocouple wire kit
that includes 30.5m (100 ft.) of type K (chromel-alumel)
thermocouple wire.
1-3
2
Card Connections and Installation
2.1 Introduction
WARNING
The procedures in this section are intended only for qualified service personnel. Do not perform these procedures
unless you are qualified to do so. F ailure
to recognize and observe normal safety
precautions could result in personal injury or death.
This section includes information on making connections to
the Model 2001-TCSCAN and on installing the card in the
DMM. This section is arranged as follows:
2.2 Handling precautions: Explains precautions that must
be followed to prevent contamination to the scanner
card assembly. Contamination could degrade the performance of the scanner card.
2.3 Connections: Covers the basics for connecting exter-
nal circuitry to the scanner card.
2.4 Typical connection schemes: Provides some typical
connection schemes for 2-pole and 4-pole operation,
including thermocouple connections.
2.5 Card installation and removal: Summarizes the pro-
cedure to install the scanner card in the DMM, outlines
scanner card output connections, and describes how to
remove the card.
2.2 Handling precautions
To maintain high impedance isolation between channels,
care should be taken when handling the scanner card to avoid
contamination from such foreign materials as body oils.
Such contamination can substantially lower leakage resistances, degrading card performance. To avoid possible contamination, always grasp the scanner card by the side edges
or covers. Do not touch board surfaces, components, or areas
adjacent to electrical contacts.
Dirt build-up over a period of time is another possible source
of contamination. To avoid this problem, operate the multimeter and scanner card in a clean environment. If the card
becomes contaminated, it should be thoroughly cleaned as
explained in paragraph 4.2.
2.3 Connections
This paragraph provides the information necessary to connect your thermocouples or other external test circuitry to the
scanner card.
WARNING
The following connection information is
intended to be used by qualified service
personnel. Failure to recognize and observe standard safety precautions could
result in personal injury or death.
2-1
Card Connections and Installation
NOTE
All connecting wires or leads must be connected to the card before it is installed in
the DMM.
2.3.1 Card configuration
Figure 2-1 shows a simplified schematic diagram of the
Model 2001-TCSCAN. The scanner card has nine input
channels and two outputs. Channel 1 is the reference junction used for thermocouple temperature measurements.
Channel 1
(Reference
Junction)
4-pole paired channels are as follows:
• Channels 2 and 7
• Channels 3 and 8
• Channels 4 and 9
• Channels 5 and 10
CAUTION
Do not attempt to pair channels 1 and 6.
Possible damage to the reference junction may result if a signal is applied to
channel 6 if channels 1 and 6 are used
together in the 4-pole mode.
Channel 2-4
Channel 5
Channel 6
Channel 7-9
Channel 10
HI
LO
HI
LO
HI
LO
HI
OUT A (To DMM
input jacks)
LO
HI
OUT B (To DMM
sense jacks)
LO
2-Pole4-Pole
Figure 2-1
Model 2001-TCSCAN simplified schematic
2-2
Card Connections and Installation
2.3.2 Card connectors
Figure 2-2 shows the input/output connectors for the card.
Card connections include:
• CH 2-10 (channels 2-10): HI and LO input terminals
are provided for each of the nine channels on the card.
NOTE
Channels 5 and 10 have current-limiting
resistors installed. Path resistance for
these two channels is approximately
240 Ω .
• OUT A: HI and LO output connections for all nine
channels in the 2-pole mode or channels 2-5 in the 4pole mode.
• OUT B: HI and LO output connections for channels 710 in the 4-pole mode.
In order to gain access to the connections, first open the plastic shield by pressing in on the locking tab. Swing the shield
away from the circuit board.
2.3.3 Wiring procedure
Perform the following procedure to wire circuitry to the
screw terminals on the scanner card.
WARNING
Make sure all power is off and any
stored energy in external circuitry is
discharged before connecting or disconnecting wires.
CAUTION
Mechanical shock may open or close
latching relays on the scanner card. Before enabling any external sour ces, open
all relays by inserting the Model 2001TCSCAN into the DMM and turning on
the power.
Locking Tab
Figure 2-2
Card connectors
Input/Output Connectors
HI LO
HI LO
HI LO
CH 4
HI LO
CH 5
CH 3
CH 2 OUT A OUT B
HI LO
CH 6
HI LO
HI LO
CH 8
HI LO
CH 9
CH 7
Plastic Shield
Reference Junction Sensor
HI LO
HI LO HI LO
CH 10
Reference Junction Circuitry
2-3
Card Connections and Installation
1. Open the plastic shield to gain access to the connectors.
2. Strip approximately
each wire.
Standard thermocouple wire or #22 AWG
stranded wire is recommended for scanner
card connections.
3. Turn the scre w terminal se veral turns counter -clockwise
until the access hole is open. Insert the wire in the access
hole.
4. While holding the wire in place, tighten the connector
screw securely.
Be sure not to over tighten screw terminals, or the connectors may be damaged.
5. Repeat steps 2 through 4 for each wire to be connected.
¼
” of insulation from the end of
NOTE
CAUTION
2.3.4 Output connections
Use the supplied test leads for scanner output connections.
Connect red leads to the output (OUT A and OUT B) HI ter minals, and connect black leads to the output LO terminals.
See Figure 2-3 for details. Dress output test leads through the
cable clamp, as described in paragraph 2.3.5. After all wires
are connected and secure, close the plastic shield, and secure
it with the locking tab.
NOTE
If you intend to use the scanner card only
in the 2-pole mode, it is not necessary to
connect output leads to both OUT A and
OUT B. Use only OUT A for the 2-pole
mode.
After the scanner card is installed, the output leads must be
connected to the multimeter rear panel input jacks. See paragraph 2.5.2 for details.
6. Dress input wires through the cable clamp, as discussed
in paragraph 2.3.5.
WARNING
If thermocouples are going to be floated
above 30V RMS, 42.4V peak, 60VDC,
make sure thermocouple wires ha ve adequate insulation.
2.3.5 Dressing leads
After wires are connected to the terminal blocks, they should
be dressed through the cable clamp as shown in Figure 2-4.
T o do so, unlatch the clip that holds the cable clamp together ,
then route all wires flat against the lower half of the clamp.
Clamp the wires down, then secure the clamp with the metal
clip unlatched earlier.
2-4
Card Connections and Installation
Figure 2-3
Output connections
HI
To DMM
Input Jacks
LO
Red
Black
Red
HI LO
HI LO
HI LO
HI LO
HI LO
HI LO
HI LO
HI LO
HI LO
CH 2 OUT A OUT B
CH 3
CH 4
CH 5
CH 6
CH 7
CH 8
CH 9
CH 10
HI LO HI LO
Note: OUT B connections not required
for 2-pole operation.
HI
To DMM
Sense Jacks
LO
Black
HI LO
CH 2 OUT A OUT B
Figure 2-4
Routing wires through cable clamp
HI LO
CH 3
HI LO
CH 4
HI LO
CH 5
HI LO
CH 6
HI LO
CH 7
HI LO
CH 8
HI LO
CH 9
HI LO
CH 10
Metal Clip
HI LO HI LO
Cable Clamp
2-5
Card Connections and Installation
2.4 T ypical connecting schemes
The following paragraphs discuss typical connections for the
scanner card.
HI HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO
CH 2
CH 3
CH 4
CH 5
CH 6
CH 7
CH 8
CH 9
CH 10
OUT A
LO
2.4.1 Thermocouple connections
Figure 2-5 shows typical thermocouple connections. Note
that thermocouples are connected to channels 2-10, and output connections are taken from the OUT A terminals.
+
-
+
-
+
Thermocouples
-
+
-
+
-
+
-
+
-
+
-
+
-
HI
LO
Thermocouples
To DMM Input Jacks
OUT B
2001-TCSCAN Card
Figure 2-5
Typical connections for thermocouple scanning
2-6
Card Connections and Installation
2.4.2 Voltage connections
Figure 2-6 shows typical connections for voltage measurements. Note that up to nine voltage sources can be switched
with this configuration. This basic configuration can be used
for the following types of measurements:
HI
CH 2
LO
HI
CH 3
CH 4
CH 5
CH 6
CH 7
CH 8
CH 9
CH 10
OUT A
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI LO
HI
LO HI LO HI LO
• DCV
•ACV
• Frequency
Channels (2-10) can be used with this configuration.
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
To DMM Input Jacks
LO
Voltages
Under Test
OUT B
2001-TCSCAN Card
Figure 2-6
Connections for voltage scanning
HI LO
2-7
Card Connections and Installation
■
■
2.4.3 Resistance connections
2-Pole connections
Figure 2-7 shows typical 2-pole resistor test connections.
The 2-pole resistance configuration can be used to test up to
seven DUTs.
NOTE
Channels 5 and 10 should not be used to
switch 2-wire resistance measurements
because of the relatively high path resistance ( ≅ 240 Ω ) of these two channels due
HI HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO
CH 2
CH 3
CH 4
LO
to the factory-installed current-limiting resistors. (Unless the card is modified; see
paragraph 4.8.)
4-Pole connections
T ypical 4-pole resistance connections are sho wn in Figure 2-
8. This general configuration can be used with channel pairs
2-5 and 7-10 to scan:
• 4-wire resistance measurements.
• 4-wire RTD temperature measurements.
CH 5
CH 6
CH 7
CH 8
CH 9
CH 10
OUT A
OUT B
2001-TCSCAN Card
Figure 2-7
Typical connections for 2-wire resistance scanning
Resistors
Under Test
HI
To DMM Input Jacks
LO
NOTE: Do not use channels 5 and 10
for 2-wire resistance measurements
2-8
CH 2
CH 3
CH 4
CH 5
CH 6
CH 7
CH 8
Card Connections and Installation
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI LO
Resistors
Under Test
HI
CH 9
LO HI LO HI LO
CH 10
OUT A
HI LO
OUT B
2001-TCSCAN Card
Figure 2-8
Typical connections for 4-wire resistance scanning
HI
To DMM Input Jacks
LO
HI
To DMM Sense Jacks
LO
2-9
Card Connections and Installation
2.5 Card installation and removal
This paragraph explains how to install and remov e the Model
2001-TCSCAN card assembly from the DMM.
WARNING
Installation or removal of the Model
2001-TCSCAN should be performed
only by qualified service personnel.
Failure to recognize and observe standard safety precautions could result in
personal injury or death.
CAUTION
To prevent contamination to the scanner card that could degrade performance, handle the card assembly only
by the card edges and covers.
NOTE
Wiring connections must made before installing the scanner card. See paragraph
2.4 for wiring details.
2.5.1 Scanner card installation
Perform the following steps and refer to Figure 2-9 to install
the card assembly in the DMM:
WARNING
Turn off power to all instrumentation
(including the DMM), and disconnect
all line cords. Make sure all power is removed and any stored energy in external circuitry is discharged.
1. Remove the cover plate from the OPTION SLOT on the
rear panel of the DMM. T o do so, pry out the two f asteners, then remove the cover plate.
2. Slide the card edges into the guide rails inside the multimeter (solder side up).
3. With the ejector arms in the unlocked position, carefully
push the card all the way forward until the arms engage
the ejector clips. Push both arms inward to lock the card
into the multimeter.
4. After installation, connect the output leads to the multimeter as discussed below.
2-10
Unlock card
Ejector Arms (2)
Card Connections and Installation
Figure 2-9
Card installation
Lock card
WARNING: Installation or removal
should be performed only
by qualified service personel.
2-11
Card Connections and Installation
2.5.2 Output connections to multimeter
After installation, connect the scanner card output leads to
the DMM rear panel jacks as follows:
• For 2-pole operation, connect OUT A HI (red) to INPUT HI, and connect OUT A LO (black) to INPUT LO.
See Figure 2-10.
• For 4-pole operation, connect OUT A HI (red) to INPUT HI, and connect OUT A LO (black) to INPUT LO.
Also connect OUT B HI (red) to SENSE HI, and connect OUT B LO (black) to SENSE LO. See Figure 2-11.
NOTE
Be sure to select the rear inputs with the
DMM front panel INPUTS switch when
using the scanner.
2.5.3 Scanner card removal
Follow the steps below to remove the scanner card from the
multimeter:
WARNING
Turn off power to all instrumentation
(including the DMM) and disconnect all
line cords. Make sure all power is removed and any stored energy in external circuitry is discharged.
1. Unlock the card by pulling the latches outward.
2. Carefully slide the card out of the multimeter.
3. If the multimeter is to be operated without a scanner
card installed, install the cover plate over the OPTION
SLOT.
2-12
Card Connections and Installation
2-13
Card Connections and Installation
Out A
HI (Red)
Use this configuration
for : DCV
ACV
2-wire Ω
2-wire RTD
Frequency
Thermocouple
Input HI
Input LO
Out A
LO (Black)
A. Models 2001 and 2002
Input LO
Use this configuration
for : DCV
ACV
2-wire Ω
2-wire RTD (Model 2010)
Thermocouple
LO (Black)
Input HI
Out A
Out A
HI (Red)
B. Models 2000 and 2010
Figure 2-10
2-pole output connections
2-14
Loading...