Tektronix 7014 Instruction Manual

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Instruction Manual

3%Channel Thermocouple/

General Purpose Multiplexer Card

Contains Operating and Servicing information

Model 7014

WARRANTY

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.

Kcithley 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, WC will, at our option, either repair or replace any product that proves to be defect&

To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio. You 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.

LIMITATION OF WARRANTY

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-rechargcahle 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 KFITHLEY 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 PROPERTY.

Model 7014 Instruction Manual

01992, Keithley Instruments, Inc.

Cleveland, Ohio, U. S. A.

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 tlw 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 70~901.01) ............................................................................ October 1992

Revision B (Document Number 7014.901-01). ........................................................................

November 1992

Safety Precautions

The following safety precautions should be observed bcforc using this product and any associated instrumentation. Although some instmmcnt~ and accessories would nomxally bc used with non-hazardous voltages, there are situations where hazardous conditions may be presem.

This producl is intended for use by qualified personnel who recognize shock hazards and are familiar with the safely precautions rcquired to avoid possible injury. Read the operating information arcfully before using the product.

The types of product users are: Responsible body is the individual or group responsible for the USC

and maintenance of cquipmcnt. for ensuring that the equipment is operated within its spccitications and operating limits, and for en-

suring that operators are adequately trained.

Operators use the product for its intended function. They mull 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 pafonn 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 pcrform them. Otherwise, they should be performed only by service pxs0”“e1.

Service personnel are trained to work on live circuits, and perform safe installations and repairs of pmducts. Only properly trained service personnel may perform installation and sen%x procedures.

Users of this product must bc protected from electric shock at all times. The rcsponsiblc body must ensure that users are prevented access and/or insulated from every connection point. In some c.xses. connections must bc exposed to potendal human contact. Product users in these circumstances must bc trained to protect thcn~scl~es 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 lntemetional Elcctrmcchnical Commission (IEC) Standard IEC 664, digital muldmeter measuring circuits (e.g.. Kcithley Models 175A, 199. 2000. 2001. 2002. and 2010) arc

lnstallatiou Category II. All other instruments signal terminals are

Installation Category I and must not bc connected to mains.

Do not connect switching cards directly to unlimited power circuits. ‘hey arc intended to be used with impcdancc limiled sources.

NEVER connect switching cards directly to AC mains. When con-

necting sources to switching cards. install protective devices to iim

it fault current and voltage to the card

Before operating an inwument, make sure the lint cord is connects ed to B properly grounded power receptacle. lnspcct the connecting

cables. test leads, and jumpers for possible wear, cracks. or brwks

before each use.

For maximum safety, do not touch the product. test cables, or .vly

other inatrumcnrs while power is applied to the circuit under test.

ALWAYS remove power from the entire test system and discharge

any capacitors before: connecting or dirconnecdng cables or jumpy

em, instdting 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 Sandards Institute (ANSI) states that B 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 before 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 ,,,~a~“rcm~“ts with dry hands while standing on a

dry, insulaled 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 cquipment may be impaired.

The WARNING heading in a manual explains dangers that might result in personal injury or death. Always read the associated information very canfully before performing the indicated procedure.

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 fame 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.

Ifa@ screw is present, connect it to safety earth ground using the wire recommended in the user documentation.

Then. symbol on an instrument indicates that the user should reker to the operating instructions located in tbc manual.

men sure 1000 volts or more, including tbc combined effect of normal and common mode voltages. Use standard safety precautions to

avoid personal contact with thcsc voltages.

symbol on an instrument shows that it am source ormea-

The CAUTION heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the warranty.

Instrumentation and accessarics 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 tire, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keirhley hutnmenrs. 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 arc equivalent to the original component. (Note that selected parts should be purchased only through Keithley lnstmments 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, USC a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do not apply cleaner directly to the instmmcnt or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with no case or chassis (c.g., data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the board becomes contaminated and opertiion is affected, the board should bc returned to the factory for proper clcaning/scrvicing.

Rev. IO/99

39 Channel Thermocouple/General Purpose Multiplexer

10.7’C ((PC to 18°C and 2FC to M”C).

REFERENCE o-: +*wu”Pc ,+SP.mn” at 0°C).

Model 7014

Bankss-‘

1 General Information

Table of Contents

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.7.1

1.72

1.7.3

1.7.4

1.8

2.1

2.2

2.2.1

2.2.2

2.2.3

2.2.4

2.3

2.3.1

2.3.2

2.4

2.4.1

2.4.2

2.4.3

2.4.4

2.4.5

2.5

2.5.1

2.5.2

Introduction Features.. Warranty information.. Manual addenda Safety Specifications Unpacking and

Inspection for damage.. ...........................................................................................................................

Shipping contents.. ...................................................................................................................................

Instruction manual.. .................................................................................................................................

Repacking for shipment..

Optional accessories

......................................................................................................................................................

............................................................................................................................................................

....................................................................................................................................

..............................................................................................................................................

symbols and terms ...............................................................................................................................

....................................................................................................................................................

inspection.. ............................................................................................................................

........................................................................................................................

.........................................................................................................................................

Multiplexing Basics

Introduction Thermocouple measurements

Definitions ..................................................................................................................................................

Theory .........................................................................................................................................................

Measurement procedure

Measuring example.. .................................................................................................................................

Basic multiplexer configurations

Multiplexer bank-to-bank jumpers

Backplane jumpers ...................................................................................................................................

Typical multiplexer switching schemes..

Thermocouple switching..

Single-ended switching ...........................................................................................................................

Differential switching ..............................................................................................................................

Sensing SMU connections

Multiplexer expansion

Two-card switching systems Mainframe multiplexer expansion

......................................................................................................................................................

........................................................................................................................

..........................................................................................................................

...................................................................................................................

........................................................................................................

......................................................................................................

........................................................................................................................

.......................................................................................................................................................

......................................................................................................................................

...................................................................................................................................

................................................................................................................

......................................................................................................

1-l 1-l 1-2 1-2 1-2 1-2 t-2 1-2 1-2 l-3 l-3 l-3

2-l

.2-l

2-l 2-l 2-2 2-2 2-3 2-4 2-6 2-7 2-7 2-8 2-8 2-9

2-9 Z-10 Z-10 2-l 1

Card Connections & Installation

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

3.5

4.1

4.2

4.3

4.3.1

4.3.2

4.3.3

4.4

4.4.1

4.4.2

4.4.3

4.4.4

4.5

4.5.1

4.5.2

4.5.3

4.5.4

4.5.5

4.5.6

4.5.7

Introduction.. Handling precautions

Connections .......................................................................................................................................................

Bank-to-bank jumpers.. Backplane jumpers Screw terminal

Typical connection

Single card system.. Two-card system.. Two-mainframe

Model 7014 installation

.....................................................................................................................................................

......................................................................................................................................

............................................................................................................................

...................................................................................................................................

connector card ...............................................................................................................

schemes.. ..........................................................................................................................

..................................................................................................................................

.....................................................................................................................................

system.. .........................................................................................................................

and removal ..........................................................................................................

3-1 3-l 3-l 3-2 3-4 3-4 3-6 3-6 3-9 3-9

3-12

Operation

Introduction.. .....................................................................................................................................................

Power limits.. .....................................................................................................................................................

Mainframe control

Channel assignments Front panel control IEEE-488 bus

Multiplexer switching examples

Thermocouple Resistor testing.. Transistor testing Resistor temperature coefficient testing..

Measurement considerations

Thermocouple Path isolation.. Magnetic fields.. Radio frequency Ground loops Keeping connectors AC frequency

of multiplexer card..

...............................................................................................................................

...................................................................................................................................

operation.. ..........................................................................................................................

....................................................................................................................

scanning ..........................................................................................................................

........................................................................................................................................

....................................................................................................................................

........................................................................................................................

measurement error

.........................................................................................................................................

......................................................................................................................................

interference.. ..............................................................................................................

..........................................................................................................................................

clean.. ....................................................................................................................

response.. ........................................................................................................................

.......................................................................................................

.............................................................................................

sources ........................................................................................

4-l 4-1 4-l 4-l

4-3 4-4 4-5 4-5 4-5

4.10

4.13 4-13 4-14 4-15 4-15 4-15 4-16 4-16

5 Service Information

5.1

5.2

5.3

5.3.1

5.3.2

5.3.3

5.3.4

5.3.5

5.3.6

5.3.7

5.3.8

5.4

Introduction.. .....................................................................................................................................................

Handling and cleaning

Performance verification ...................................................................................................................................

Environmental Recommended Reference junction Channel resistance Offset current

contact potential tests.. ............................................................................................................................

Bank and channel-to-channel isolation tests Differential and common-mode isolation tests

Calibration..

tests.. ..................................................................................................................................

......................................................................................................................................................

5-l

precautions.. .............................................................................................................

conditions .......................................................................................................................

equipment ......................................................................................................................

test ..............................................................................................................................

tests.. .........................................................................................................................

........................................................................................

..................................................................................

5-l 5-2 5-2 5-2 5-3 5-5 5-6 5-E

5.9

5.13

5.15

5.4.1

5.4.2

5.5

5.6

5.6.1

5.6.2

5.6.3

5.6.4

5.6.5

5.7

5.7.1

5.7.2

5.7.3

Calibration with thermistor probe.. .....................................................................................................

Calibration with thermocouple wire..

Special handling of static-sensitive devices

Prlnc1ples of operation

Block diagram

ID data cncults .........................................................................................................................................

Relay control

Reference junction .................................................................................................................................

Power-on safeguard

Troubleshooting

Troubleshooting equipment Troubleshooting access Troubleshooting procedure

...................................................................................................................................

........................................................................................................................................

..........................................................................................................................................

..............................................................................................................................

............................................................................................................................................

................................................................................................................

.........................................................................................................................

.................................................................................................................

..................................................................................................

................................................................................................

.5-15

5-17 5-19 5-19

5-19 5-20

5-21 5-21 5-21 5-21 5-21 5-21 5-22

6.1

6.2

6.3

6.4

6.5

Replaceable Parts

Introduction Parts lists.. Ordering information Factory service

Component layouts and schematic diagrams.

.....................................................................................................................................................

.........................................................................................................................................................

.....................................................................................................................................

.................................................................................................................................................

6-l 6-1 6-l 6-l

............................................................................................

6-l

iii/iv

List of I Ilustrations

Figure 2-1 Figure 2-2 Figure 2-3 Figure 2-4 Figure 2-5 Figure 2-6 Figure 2-7 Figure 2-8 Figure 2-9 Figure Z-10 Figure 2-11 Figure 2-12 Figure 2-13 Figure 2-14 Figure 2-15

Figure 3-l Figure 3-2 Figure 3-3 Figure 3-4 Figure 3-5 Figure 3-6 Figure 3-7 Figure 3-8 Figure 3-9 Figure 3-10

Figure 3-11 Figure 3-12 Figure 3-13

Multiplexing Basics

Thermocouple measurement

Model 7014 simplified schematic Four 1 x 10 multiplexer configuration Two 1 x 20 multiplexer configuration

One 1 x 40 multiplexer configuration (jumpers installed)

Model 7001 analog backplane..

Bank connections to backplane Thermocouple switching example..

Single-ended switching example

Differential switching example

Sensing example

SMU connections.. ..................................................................................................................................

Two separate multiplexer systems

Multiplexer input expansion example

Mixed card type example

.......................................................................................................................................

...................................................................................................................

...........................................................................................................

(jumpers not installed) .........................................................

(jumpers installed). ................................................................

................................................................. 2-5

..............................................................................................................

.............................................................................................................. 2-7

.......................................................................................................

...........................................................................................................

.............................................................................................................. 2-8

...................................................................................................... 2-l 1

................................................................................................

......................................................................................................................

2-2

2-3 2-4 2-5

2-6

.2-7

.2-8

2-Y

Z-10 Z-12

2-12

Card Connections & Installation

Bank-to-bank jumper locations Bank-to-bank jumper termmal ldenhficahon Connector card mounting screw.. Bank-to-bank jumper installation

Backplane jumpers ...................................................................................................................................

Model 7014 screw terminal connector card Typical screw terminal connections Cable clamp for screw terminal connector card Single card (1 x 39) system example.. Single card (1 x 19 and 1 x 20) system example.. Two-card system example Two-mainframe system example.. Model 7014 card installation in Model 7001

.............................................................................................................. 3-2

..........................................................................................

...........................................................................................................

..........................................................................................................

..........................................................................................

......................................................................................................

..................................................................................

.....................................................................................................

..................................................................................

.................................................................................................................... 3-10

....................................................................................................... 3-11

.......................................................................................

3-3

3-4

3-5

3-6

3-7

3-8

3-13

Figure 4-l Figure 4-2

Operation

Channel status display ,,,,,,,....,.,,,,..,,,,,,,.,,.,,,,,,....,,.,,...,...,,,,,,,,,,.,....,,......,.......................,,,..................... 4-2

Display organization for multiplexer channels . . . . . .

4-2

”

Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Figure 4-7 Figure 4-8 Figure 4-9 Figure 4-10 Figure 4-11 Figure 4-12 Figure 4-13 Figure 4-14

Model 7014 programming channel assignments

Thermocouple scanning ...........................................................................................................................

Z-wire resistance testing ..........................................................................................................................

4.wire resistance testing ..........................................................................................................................

Low resistance testing.. ............................................................................................................................

Configuration for current gain and common-emitter test Resistor temperature coefficient testing.. Typical common-emitter characteristics

Path lsolatlon resistance.. ........................................................................................................................

Voltage attenuation by path isolation

Power lie ground loops

....................................................................................................................... 4-16

............................................................................................. 4-12

.............................................................................................

resistance ............................................................................... 4-15

Eliminating ground loops .....................................................................................................................

................................................................................. 4-3

4-6 47 4-7

4-9

................................................................

4-11 4-13

4-14

4-16

Figure 5-l Figure 5-2 Figure 5-3 Figure 5-4 Figure 5-5 Figure 5-6 Figure 5-7

Figure 5-8

Figure 5-9

Figure S-10

Figure 5-11 Figure 5-12 Figure S-13

Service Information

Reference junction test Path resistance test connections Differential offset current test connections.. contact potential test connections

Bank lsolahon test connections ...............................................................................................................

Channel-to-channel isolation test connections.. Differential isolation test connections Common-mode isolation test connections.. Calibration with thermistor probe Calibration with thermocouple wire Model 7014 block diagram Start and stop sequences Transmit and acknowledge sequence ‘

.............................................................................................................................. 5-4

............................................................................................................. 5-5

.........................................................................................

.........................................................................................................

5-7 5-8 5-9

...........................................................................

..... .

5-11

................................................................................................. S-13

........................................................................................ S-15

........................................................................................................

5-16

.................................................................................................... 5-18

.................................................................................................................... S-19

........................................................................................................................ S-20

.................................................................................................

5-20

List of Tables

Table 3-l

Table 4-1

Table 5-1 Table 5-2 Table 5-3 Table 5-4 Table 5-5

Table 5-6

Card Connections & installation

Bank-to-bank jumpers (refer to Figure 3-2) ,,,......,.,.,,,,,,,,,,,,,,,,..........,............

,,,,,,,,,........................ 3-3

Operation

Paired Channels in 4-p& Operation . . ..___....,,...............................................~.

,......,.,,,,....,.....,.,....... 4-8

Service Information

Verification and calibration equipment Bank isolation test summary Channel-to-channel isolation test summary Differential and common-mode isolation Recommended troubleshooting equipment Troubleshooting procedure

............................................................................

..................................................................................

..........................................................

..................................................

testing.. ........................................

...................................................

................................. 5-3

............................... 5-10

............................... 5-12

............................... 5-14

............................... 5-21

............................... 5-23

vii/viii

General Information

1.1 Introduction

This section contains general information about the Model 7014 3PChannel Thermocouple/General Purpose Multiplexer Card.

The Model 7014 card is field-installable in the Model 7001 Switch System. Since it combines the functions of

thermocouple switching and a uniform temperature reference, it is especially useful for scanning thermocouples.

The input terminals are covered by an aluminum cover that acts as an isothermal block to minimize temperature differences. An transducer under the aluminum cover senses the reference (cold) junction temperature and converts it to a proportional voltage. The cold junction temperature is used to calculate the corrected thermocouple output. The output voltages of each thermocouple must be converted to temperature (“C, “F, or K) using appropriate thermocouple tables, polynomial equations, or a multimeter capable of temperature measurements, such as the Model 2001.

integrated

circuit temperature

The rest of Section 1 is arranged in the following man-

*fZr:

Features

1.2 Warranty information

1.3 Manual addenda

1.4 Safety symbols and terms

1.5 Specifications

1.6 Unpacking and inspection

1.7 Repacking for shipment

1.8 Optional accessories

1.9

1.2 Features

The Model 7014 is a low voltage, two-pole, quad, 1 x 10

multiplexer card. Some of the key features include:

Low contact potential and offset current for mini-

mal effects on low-level signals.

In addition, any channel can be used for monitoring

low-level signals. The Model 7014 uses 2-p& Form A contacts for switching of DC signals up to llOV, lA, 30VA (resistive load), and AC signals up to 125V RMS or 175V peak, lA, 60VA (resistive load).

The connector board detaches from the relay

allowing easy access to the screw terminals and

jumpers.

l Easy jumper configuration of one, two,

four multiplexer banks.

three or

board

l-l

l Backplane jumpers. Cutting jumpers disconnects

multiplexer bank outputs from the Model 7001 analog backplane.

The CAUTION heading used in this manual explains hazards that could damage the multiplexer card. Such damage may invalidate the warranty.

1.3 Warranty information

Warranty information is located on the inside front cover of this instruction manual. Should your Model 7014 require warranty service, contact the Keithley representative or authorized repair facility in your area for further information. When returning the multiplexer 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.

1.4 Manual addenda

Any improvements or changes concerning the multi-

plexer

hum included with the card. Addenda are provided in a page replacement format. Simply replace the obsolete pages with the new pages.

card or manual will be exulained in an adden-

1.6 Specifications

Model 7014 specifications are found at the front of this manual. These specifications are exclusive of the multiplexer mainframe specifications.

1.7 Unpacking and inspection

1.7.1 Inspection for damage

The Model 7014 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 uerformance. Before removing the card from the bag, observe the following precautions on handling.

Handling Precautions:

1. Always grasp the card by the side edges and shields. Do not touch the board surfaces or components.

1.5 Safety symbols and terms

The following symbols and terms may be found on an instrument or used in this manual.

The A user should refer to the operating instructions located in the instruction manual.

The

voltage may be present on the terminal(s). Use standard safety precautions to avoid personal contact with these voltages.

The WARNING heading used in this manual exulains dangers that might res& in personal injury or heath. Always read the associated information very carefully before performing the indicated procedure.

symbol on an instrument indicates that the

symbol on an instrument shows that high

2. When not installed in a Model 7001 mainframe, keep the card in the anti-static bag and store it in the original packing carton.

After removing 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.

1.7.2 Shipping contents

The following items are included with every Model

7014

order:

l Model 7014 39.Channel Thermocouple/General

Purpose Multiplexer Card

l Model 7014 Instruction Manual l Additional accessories as ordered,

1-2

1.7.3 Instruction manual

The Model 7014 Instruction Manual is three-hole

drilled so that it can be added to the three-ring binder of the Model 7001 Instruction Manual. After removing

the plastic wrapping, place the manual in the binder following the mainframe instruction manual. Note that a manual identification tab is included and should precede the multiplexer card instruction manual.

Advise as to the warranty status of the thermocouple card.

Write AlTENTION REPAIR DEPARTMENT on the shipping label.

Fill out and include the service form located at the

back of this manual.

If an additional instruction manual is required, order the manual package, Keithley part number 7014-901-

00. The manual package includes an instruction manual and any pertinent addenda.

1.7.4 Repacking for shipment

Should it become necessary to return the Model 7014 for repair, carefully pack the unit in its original packing carton or the equivalent, and include the following information:

1.8 Optional accessories

The following accessories are available for use with the

Model 7014: Model 7014-ST-This isothermal screw terminal con-

nector card is identical to the one provided with the

Model 7014 assembly. An extra connector card allows you to wire a second test system.

Model 7401 - This thermocouple wire kit includes

30.5m (100 ft.) of type K (chromcl-alumcl) thcrmocouple wire.

l-3

1-4

Multiplexing Basics

2.1

This section covers the basics for multiplex switching

and is arranged as follows:

2.2

2.3

2.4

2.5

Introduction

Thermocouple measurement basics: Describes the theory of thermocouple measurements and a measurement procedure.

Basic multiplexer configurations: Covers the basic multiplex configurations; quad 1 x 10 configuration, dual 1 x 20 configuration and single 1 x 40 configuration. The significance of the backplane jumpers is also covered here.

Typical multiplexer switching schemes: Ex-

plains some of the basic ways a multiplexer can be used to source or measure. Covers single-ended switching, differential (floating) switching and sensing.

Multiplexer expansion: Discusses the various configurations that are possible by using multiple cards.

Cold junction-The junction that is held at n stable known temperature. Also known as the reference junction.

Hot junction -The junction of two dissimilar metals that is used to measure an unknown temperature. Also known as the measurement junction.

Isothermal block or cover- The metal block or cover that equalizes the temperature of thermocouple connections on a switching card.

Reference accuracy sensor and channel inside the isothermal environment. Also known as temperature offset.

Reference channel - The channel that measures the temperature of the isothermal environment.

Reference output -The output signal that represents

the temperature of the reference channel. Commonly specified by a temperature coefficient of wV/“C and an offset voltage in millivolts at 0°C.

- The maximum error between

2.2

2.2.1 Definitions

The following terms are defined as they relate to thermocouple circuits and thermocouple switching cards:

Thermocouple measurements

2.2.2 A thermocouple is a junction formed between two dis-

similar metals. If the temperature of the thermocouple junction connected to the Model 7014 is T, a voltage E is developed between leads A and B as shown in Figure 2-1. When connected to a voltmeter, two more junctions (C and D) are formed with the meter terminals,

Theory

which are usually copper. The measured voltage is proportional to the difference between temperatures Tand T7.

Fi@~re 2- 1

Thermocouple measurement

To determine the difference, the thermoelectric properties of the thermocouple are needed. Data is available to determine the voltage Y~~-SLIS temperature relationship based on a reference temperature (T1) of 0°C. Thus, if the thermocouple-to-copper junctions were maintained at O”C, it would be possible to determine T

by referring to the Thermocouple Reference Tables.

(See NIST Monograph 125). The tables list temperature as a function of the meter reading E,. Since these junctions are not OT, a voltage E, is inhoduced, where:

+54.63mV at O”C, convert the voltage reading to

temperature (TI) with the formula: T, = (El - 54.63mV) / 0.2mV per “C T, represents the temperature of the Model 7014

isothermal connections.

Using the thermocouple look-up tables or the following formula, convert the temperature (T,) from step 1 to a voltage. Use tables matching the type of thermocouple connected to the Model 7014. E, COTresponds to the reference voltage that would result if an actual thermocouple were used as a reference

junction. E, = a0 + a,T + a,F + a,T3 + a,T4

Make a measurement of the voltage (E,) developed by the thermocouple connected to the Model 7014.

Add the reference voltage derived in step 2 to the thermocouple voltage measured in step 3.

E = E, + E,

Convert the voltage sum (E) from step 4 to a temperature (T) using either thermocouple look-up tables or the formula:

E, = E - E,

2.2.3 Measurement procedure

The temperature of a thermocouple junction is determined by the following summarized procedure:

l Measure the reference voltage (E,).

. Calculate the reference temperature (TI). . Determine the reference correction voltage (E,).

l Measure the thermocouple voltage (E,). l Calculate the thermocouple correction voltage (E). l Determine the thermocouple temperature (T).

The complete step-by-step procedure follows:

1. Read the voltage (E,) developed by the Model 7014 reference junction. Assuming a temperature coefficient of +2OOpV/“C, and an offset voltage of

T = a, + a,E + a,E2 + a,E” + a4E4

The values for a, through a4 for the supported thermocouples are listed in tables located in Appendix A.

2.2.4 Measuring example

A measurement setup uses a Type J thermocouple. The voltage developed by the reference junction (channel 1) is 61.83mV. The voltage read from the thermocouple is

14476pV.

1. Find the temperature of the isothermal connections. The voltage from the reference sensor is

61.83mV (61.83mV - 54.63mV) / 0.2mV per “C = 36°C

Using the appropriate formula or thermocouple look-up tables (see Table 6.32 of NIST Monograph

125), find the equivalent voltage developed by a

Type J thermocouple at 36°C. This voltage is found to be 1849.11iv. The formula shown in Step 2 above would yield 1849.085cLv.

2-2

3. The voltage developed by the thermocouple is measured as 14476vV.

The sum of the voltage is 14476 + 1849.1, or

16325.1pV.

5. Using the appropriate formula or thermocouple look-up tables (see Table A6.2.1 of NIST Monograph 125), find the temperature for a Type J thermocouple corresponding to 16325.1pV. This temperature is 3OO.O”C. The formula shown in step 5 above would yield 299.995%

NOTE

A multimeter with a temperature function, such as a Keithley Model 2001, will perform the measurement

procedure automatically, except for closing and opening channels on cxternal cards.

2.3

A simplified schematic of the Model 7014 Thermocouple Card is shown in Figure 2-2. It is organized as four

1 x 10 multiplexer banks. Each bank has 10 inputs and one output. (Note that Input 1 of Bank A is the reference junction.) Two-pole switching is provided for each multiplexer input, with HI and LO switched. Two or more banks can bc jumpered together to expand multiplexer inputs, and backplane jumpers provide bank connections to n second card installed in a Model

Basic multiplexer configurations

Fi@we 2-2 Model 7014 simplified schematic

2.3.1 Multiplexer bank-to-bank jumpers

plexer configurations include:

NOTE

When mixing applications on a Model 7014 card, bank jumpers can be removed to isolated different signal levels. However,

switching different levels simultaneously may affect the card’s reference accuracy.

Jumpers are installed on the connector card to connect multiplexer banks together to form a multiplexer of 1 x

39. Each jumper set connects two adjacent banks together. These jumper sets are included with the Model

7014.

The bank-to-bank jumpers allow you to configure the multiplexer card in a variety of ways. Typical multi-

Reference

Junction

Bank A

= ,‘I ; ;f---h+OutputA

ioc ,’

m Four 1 x 10 multiplexers; no jumpers installed (Fig-

ure 2-3).

l Two 1 x 20 multiplexers; Bank A jumpered to Bank

B, Bank C jumpered to Bank D (Figure Z-4).

l One 1 x 40 multiplexer; all bank-to-bank jumpers

installed (Figure 2-5).

Other combinations are possible, including multiplex-

ers of various sizes (in multiples of 10 channels). For example, you could install jumpers to configure the card as one 1 x 30 and one 1 x 10 multiplexer.

Refer to Section 3 for information on installing bank-tobank jumpers.

1* ,’

Bank C

10. ,’

1. ,’

Bank D

10. ,’

Figure 2-3 Four 1 x 10 multiplexer configuration (jumpers not installed)

2-4

Reference

Junction

Bank A

Inputs

- ‘1: ; ;--+.y+O”tp”tA

10* ,

1. ,j2

Bank B

10. ,,2

1. ,z2

Bank C

10. /2

Bank D

Figure 2-4

Two 1 x 20 multiplexer configuration (jumpers installed)

. .

output c

Bank B

Bank C

Bank D

I.- ,j2

10. ,,z

1. ,f2

IO. ,z2

1* ,,2

10. ,j2

Jumpers

2-5

2.3.2 Backplane jumpers

NOTE

When mixing applications in a Model 7001 mainframe, backplane jumpers on 701X-series cards can be removed to isolate different signal levels. However, switching different levels simultaneously may affect the card’s

reference accuracy.

There are four pairs of backplane jumpers located on the relay card. With the jumpers installed, the banks of

Model 7001

the multiplexer card are connected to the analog backplane of the Model 7001 allowing expansion with a second 701X-series card installed in the mainframe. With the jumpers removed (cut), the multiplexer card is isolated from another card installed in the mainframe.

The three-pole analog backplane of the Model 7001 mainframe is shown in Figure 2-6. Through this analog backplane the banks of a Model 7014 multiplexer card, installed in one slot, can be connected to the banks (or rows) of a compatible card installed in the other slot of the mainframe.

Card 1 Card 2

: I

H> I<H L\!PI’L G-I’=

I I I I

H>I L\IPl’L G-G

I “? P L! P

=>I

H>I 4 IL

=>I

Analog

Backplane

Row 1 or Bank A

ROW 2 or Bank B

ROW 3 oi Bank c

ROW 4 or Bank 0

r----l I

I<”

I Lee---------.

Figure 2-6

Model 7001 analog backplane

2-6

Figure 2-7 shows how each bank of the Model 7014 is connected to the backplane. Notice that since the Model 7014 is a two-pole card, there is no connection made to the Guard terminal of the backplane. The Model 7014 is shipped from the factory with the backplane jumpers installed.

ries cards. As a result, any of these cards installed in one slot in the mainframe is electrically isolated from

any

card installed in the other slot. The only way to connect a Model 7014 to one of these cards is to wire them together.

7014 Bank

(1 Of 4)

H‘A.) H

L-J::

H = High L=Lmv G = Guard

Figure2-7

Bank connections to backplane

Backplane

.l”fllp~~S

Removing (cutting) the backplane jumpers isolates the card from the backplane, and subsequently, any card installed in the other slot. For information on removing the jumpers, refer to Section 3.

NOTE

The Model 7001 does not provide an analog backplane for the non-701X se-

2.4 Typical multiplexer switching schemes

The following paragraphs describe some basic switching schemes that are possible with a two-pole switching multiplexer. These switching schemes include some various shielding configurations to help minimize noise pick up in sensitive tions. These shields are shown connected to chassis ground. For some test configurations, shielding may prove to be more effcctivc connected to circuit common. Chassis ground is accessible at thr rear panel of the Model 7001.

2.4.1 Thermocouple switching

In a typical switching configuration for thermocouples, all banks on the Model 7014 are connected together. As shown in Figure 2-7, the voltage is connected to one of the card outputs, and up to 39 thermocouples arc connected to the inputs.

measurement applica-

measuring instrument

Figure2-8

Thermocouple switching example

input 2-40

+t-------

Thermocouple

2-7

2.4.2 Single-ended switching 2.4.3 Differential switching

In the single-ended switching configuration, the source or measure instrument is connected to the DUT through a single pathway as shown in Figure 2-9. The

instrument is connected to the output of one of the banks and the DUT is shown connected to one of the inputs for that bank.

The differential or floating switching configuration is shown in Figure Z-10. The advantage of using this con-

figuration is that the terminals of the SOUIC~ or measure instiument are not confined to the same pathway. Each terminal of the instrument can be switched to any available input in the test system.

* Optional

Shield

Note: There are no user connections for the

reference junction (Bank A, Input 1).

Figure 2-9 Sing/e-ended switching example

Figure 2- 10 Differential switching example

Note: There are no user connections for the

reference junction (Bank A, Input 1).

2-E

2.4.4 Sensing 2.4.5 SMU connections

Figure 2-11 shows how the multiplexer card can be configured to use instruments that have sensing capa-

bility The main advantage of using sensing is to cancel

the effects of switch card path resistance (<la) and the resistance of external cabling. Whenever path resistance is a consideration, sensing should be

used.

Bank C, D

Figure 2-12 shows how to connect a Keithley Model 236,237 or 238 Source Measure Unit to the multiplexer card. By using triax cables that are unterminated at one end, the driven guard and chassis ground are physically extended all the way to thr card.

7 ^

Input i-10

Input I-IO

Note: There are no user connections for the

reference junction (Bank A, Input 1).

Figure 2- 11

Sensing example

2-9

Bank A, B I

ZEZP

7014

Input l-10

DUT

I”

Input l-10

Note: There are no user connections for the

reference junction (Bank A, Input 1).

WARNING : Hazardous voltages may be preSe”t on

Figure 2-

SMU connections

GUARD. Make sure all cable shields are properly insulated before applying power.

2.5 Multiplexer expansion

With the use of additional switching cards and mainframes, larger systems can be configured. Each Model

7001 Switch System mainframe will accommodate up to two cards, and up to six mainframes can be connected together. Thus, a switch system using as many as 12 cards can be configured.

NOTE

When mixing applications in a Model

7001 mainframe, backplane jumpers on 701X.series cards can be removed to isolate different signal levels. However, switching different levels simultaneously may affect the card’s reference accuracy.

Separate switching systems

2.5.1 Two-card switching systems

Each Model 7001 Switch System mainframe can accommodate two cards to allow the following switching

configurations.

2-l 0

Two single-card systems can be configured by removing the backplane jumpers from one of the cards. The two cards will be controlled by the same mainframe, but they will be electrically isolated from each other. Figure 2-13 shows an example using two Model 7014 multiplexer cards.

Four 1x10 Multiplexers

Card 2

L---------------_

Four 1x10 Multiplexers

Backplane

.hmpers FbXllO”C3d

Multiplexer input expansion

You can double the number of multiplexer inputs by simply installing two “as shipped” Model 7014s in the Model 7001 mainframe. By leaving the backplane jumpers installed, the banks of the multiplexer card installed in slot 1 (CARD 1) are automatically connected to the banks of the multiplexer card installed in slot 2 (CARD 2) through the analog backplane.

Figure 2-14 shows an example of input expansion. Each Model 7014 card is configured as four 1 x 10 multiplexers. By connecting the banks together (via Model 7001 analog backplane), the resultant multiplexer system has 20 inputs for each of the four banks. Notice that if all the bank-to-bank jumpers (for both cards) were installed, the result would be a single 1 x 80 multiplexer.

Mixing card types

Different types of cards can be used together to create some unique switching systems. For example, you

could have a Model 7014 multiplexer card installed in one slot and a Model 7012 matrix card installed in the other slot.

Figure Z-15 shows a possible switching system using a matrix card and a multiplexer card. The backplane jumpers for both the matrix and multiplexer cards must be installed. This allows matrix rows to

be con-

nected to multiplexer banks. On the multiplexer card, the bank-to-bank jumpers must be removed to maintain isolation between matrix rows. See the instruction manual for the Model 7012 for complete information on the matrix card.

2.5.2 Mainframe multiplexer expansion

Multiplexer systems using up to 12 multiplexer cards are possible if you USE six Model 7001 mainframes together. Each Model 7014 added to the system provides 39 additional inputs. Paragraph 3.4.3 explains how to connect a test system using two mainframes.

2.11

r----

Card 1 Backplane

---------_____

7cm Analog

Card 2

r-------------

Quad 1x10 Multiplexers

Figure 2- 14

Mu/t&her input expansion example

Quad

1x20 Multiplexer

---------_____ Quad 1 xl 0 Multiplexers

L--------------2

Figure 2- 15 Mixed card type example

2-12

4 x 10 Matrix

/<I 1 I ( I I II I IBank / L----------------~

Quad 1 x 10 MUX

Card Connections & Installation

3.1 Introduction

WARNING

The procedures in this section are intended only for qualified service per-

t3OIUId.

procedures unless qualified to do so. Failure to recognize and observe normal safety precautions could result in personal injury or death.

The information in this section is arranged as follows:

3.2 Handling precautions: Explains precautions that must be followed to prevent contamination to the mul-

tiplexer card assembly. Contamination could degrade the performance of the multiplexer card.

3.3

Connections: Covers the basics for connecting external circuitry to the isothermal screw terminal connector card.

Do not perform these

3.2 Handling precautions

To maintain high impedance isolation, care should be

taken when handling the relay card to avoid contamination from such foreign materials as body oils. Such contamination can substantially lower leakage resistances, thus degrading performance.

To avoid possible contamination, always grasp the relay and connector cards by the side edges or shields. Do not touch the board surfaces or components. On connectors, do not touch areas adjacent to the electrical contacts. Dirt build-up over a period of time is another possible source of contamination. To avoid this problem, operate the mainframe and multiplexer card in n clean environment.

If a card becomes contaminated, it should be thoroughly cleaned as explained in paragraph 5.2.

3.4 Typical connection schemes: Provides some typical connection schemes for single card, two-card and two-mainframe system configurations.

3.5 Model 7014 installation: Provides a procedure to install the multiplexer card assembly in the Model 7001 mainframe.

3.3 Connections

This paragraph provides the basic information needed to connect your external test circuitry to the multiplexer card. It includes the installation of the bank-to-bank jumpers on the connector card, installation/removal of backplane jumpers on the relay card, and detailed in-

formation on making external connections to the con-

nector card.

WARNING

The following connection information is intended to be used by qualified service personnel. Failure to recognize and observe standard safetv orecautions could result in personai injury or death.

3.3.1 Bank-to-bank jumpers

As explained in paragraph 2.3.1, the banks of the multiplexer card can be connected together (using plug-in jumpers) to form larger multiplexers. The locations of the bank-to-bank jumper terminals are shown in Fig-

ure 3-l

Bank-to-Bank

Jumper Terminals

Figure 3- 1 Bank-to-bank jumper locations

3-2

Terminal identification is provided by Figure 3-2. On the drawing, the six terminal pairs are labeled W201 through W206. The top three terminal pairs (W201, W203 and W205) are used to connect the HI terminals of the banks together. The bottom terminal pairs (W202, W204 and W206) are used to connect the LO terminals of the banks together. Table 3-l summarizes the effects of each jumper.

Figure 3-2 Bank-to-bank jumper terminal identification

3. Using Figure 3-4 as a guide, install the jumpers on the appropriate terminal pairs.

Bank-to-bank jumpers irefer to Figure 3-2)

Installed

jumper

w201 w202

W203 W204

W205 W206

Effect Connect Bank A HI to Bank B HI

Connect Bank A LO to Bank B LO Connect Bank B HI to Bank C HI

Connect Bank B LO to Bank C LO Connect Bank C HI to Bank D HI

Connect Bank C LO to Bank D LO

Referring to Figure 3-l for jumper locations, perform

the following steps to install bank-to-bank jumpers:

1. If mated together, separate the relay card from the connector card by removing the mounting screw and pulling the two cards away from each other (see Figure 3-4). Remember to only handle the cards by the edges and shields to avoid contamination.

2. Refer to Figure 3-2 and Table 3-l to determine which jumpers to install.

Figure 3-3 Connector card mounting screw

3.3

Jumper installation

-Jumper

Figure 3-4 Bank-to-bank jumper installation

3.3.2 Backplane jumpers

The Model 7001 mainframe has an analog backplane that allows the banks of a Model 7014 multiplexer card to be internally connected to a compatible switching card installed in the other slot (see paragraph 2.5.1 for details).

Referring to Figure 3-5 for jumper locations, perform the following steps to install backplane row jumpers:

tion.

2. Physically remove a cut jumper by unsoldering it from the PC board.

3. Install a new #22 AWG jumper wire (Keithley P/N J-15) and solder it to the PC board.

4. Remove the solder flux from the PC board The cleaning procedure is explained in paragraph 5.2.

7014

Relay Card

The backplane jumpers for the multiplexer card assetbly are located on the relay card as shown in Figure 3.

5. Tbe card is shipped from the factory with the jumpers installed.

Jumper removal

Perform the following steps to remove backplane jumpers:

If mated together, separate the relay card from the connector card by removing the mounting screw and pulling the two cards away from each other (see Figure 3-4). Remember to only handle the cards by the edges and shields to avoid contamination.

Use Figure 3-5 to locate the jumper(s) that are to be removed.

It is not necessary to physically remove the jumpers from the PC board. Using a pair of wire cutters, cut one lead of each jumper.

Figure 3-5 Backplane jumpers

3.3.3 Screw terminal connector card

The screw terminal connector card is shown in Figure 3-6. Connections are made directly to the screw terminals of the eight terminal blocks. Each screw terminal will accommodate #16-22 AWG wire.

3-4

Card Connections & Installation

Wiring procedure Perform the following procedure to wire circuitry to

the screw terminal connector card:

WARNING

Make sure all power is off and any stored energy in external circuitry is discharged.

1. If mated together, separate the connector card from the relay card by removing the mounting screw

and pulling the two cards away from each other

(see Figure 3-4). Remember to only handle the

cards by the edges and shields to avoid contamina-

tion.

2. Using an insulated screwdriver, connect the cir-

cuitry to the appropriate terminals. Figure 3-7 shows how the output of Bank C would be connected to a DMM. (Use copper wire for the output

CONWCtiOllS.)

Figure3-6 Model 7014 screw terminal connector card

WARNING

Use properly insulated wire for applications exceeding 42.4V peak or 30V RMS.

3. Referring to Figure 3-8, remove the top half of the cable clamp as follows:

A. Loosen the cable clamp screw enough to disen-

gage it from the bottom half of the cable clamp.

B. Using your thumb and forefinger, press the re-

taining clips inward and, with your other hand, remove the top half of the clamp.

3-5

4. Route wires under wire guide/connector shim. Do not route wires across the reference circuit.

5. Route the wires through the bottom half of the cable clamp.

6. Replace the top half of the clamp. It simply snaps onto the bottom half of the clamp. lighten the cable clamp screw. The clamp serves as a strain relief for terminal block wires.

7. Mate the connector card to the relay card and tighten the mounting screw. The Model 7014 is now ready to be installed in the Model 7001 mainframe. See paragraph 3.5 for details.

Figure 3-8 gable

clamp for screw terminal connector card

3.4 Typical connection schemes

The following information provides some typical connection schemes for single card, two-card and twomainframe system configurations. Keep in mind that these are only examples to demonstrate various ways

to wire a test system. Connection details are provided in paragraph 3.3.

Figure 3-7

Typical screw terminal connections

3.4.1 Single card system

The single card systems in Figure 3-9 and Figure 3-10

use the isothermal screw terminal connector card. With this card, single conductor connections are made directly from the terminal blocks of the connector card to instrumentation and DUTs.

When using a single card system, you will want to make sure that the card remains electrically isolated from any other switching cards. There are several ways to ensure isolation for a single card in the Model 7001 mainframe:

1. Vacate the other mainframe slot. If there is a Model 701X card installed in the other slot, remove it.

2. Remove the backplane jumpers on the multiplexer

card. This will disconnect the card from the analog backplane of the mainframe.

3. Remove the backplane jumpers from the switching card installed in the other slot.

3-6

DUT Test Fixture

Card Connections & Installation

Simplified Equivalent Circuit

Notes: 1. All bank-to-bank jumpers

must be installed.

2. There are no user connections for the reference junction

(BankA, Input 1).

3-7

Card Connections & installation

DUTs I I

- (lx19and 1x20)

Simplified Equivalent Circuit

Figure 3-10

Sing/e card fl x 7 9 and 1 x 20) system example

, lnstr”me”ts ,

Notes: 1. Bank-to-bank jumpers installed

as iollows :

Bank A connected to Bank B Bank C connected to Bank D

2. There are no user connections for the reference junction (Bank A, Input 1).

3-8

Card Connections & Installation

3.4.2 Figure 3-11 shows a system using two multiplexer

cards installed in one Model 7001 mainframe to configure a single 1 x 80 multiplexer system. Each card is configured as a single 1 x 40 multiplexer. To accomplish this, all bank-to-bank jumpers (both cards) are installed to connect Banks A, 8, C, and D together. By leaving the

backplane jumpers of both cards installed, the banks of

Card 1 are connected to the banks of Card 2 through the analog backplane of the Model 7001 mainframe resuiting in the 1 x 80 configuration.

Figure 3-11 shows how external connections can be

made for the connector card. Single conductor connec-

tions are made directly from the screw terminals of the connector card to the instrument and DUT.

3.4.3

Figure 3-12 shows a system using three multiplexer cards installed in two Model 7001 mainframes to con-

Two-card system

Two-mainframe system

figure a single 1 x 120 multiplexer system. Each card is configured as a single 1 x 40 multiplexer. To accomplish this, bank-to-bank jumpers of all three cards must bc installed to connect Banks A, B, C, and D together.

By leaving the backplane jumpers of the cards in mainframe #l installed, the banks of Card 1 are connected to the banks of Card 2 through the analog backplane of the Model 7001 mainframe resulting in n 1 x 80 configuration. External bank connections from the instrument to the card in the second mainframe connect the

banks of all three cards together to form the 1 x 120

multiplexer system. This system is similar to the Twocard System (see previous paragraph) except that a third multiplexer card (installed in a second mninframe) is added.

Figure 3-12 shows connections for the connector card. Single conductor connections arc made directly from the screw terminals of the connector card to the instrument and DUT.

DUT Test Fixture

Simplified Equivalent Circuit

40 42

Figure 3-

Two-card system example

3-10

( . . . . . .

Card Connections & Installation

Figure 3- 72

Two-mainframe system exampk

Simplified Equivalent Circuit

3-l 1

Card Connections &

installation

3.5 Model 7014 installation and removal

This paragraph explains how to install and remove the Model 7014 multiplexer card assembly from the Model 7001 mainframe.

WARNING

Installation or removal of the Model 7014 is to be performed by qualified service personnel. Failure to recognize and observe standard safety precautions could result in personal injury or death.

NOTE

Make sure your external circuitry is

wired to the card (as explained in

paragraph 3.3.1) before installing the

card assembly in the Model 7001

mainframe.

WARNING

Turn off power from all instnunenta-

tion (including the Model 7001 mainframe) and disconnect their line

cords. Make mm all power is removed and any stored energy in external circuitry is discharged.

1. Mate the connector card to the relay card if they are separated. Install the supplied 4-40 screw at the end of the card to secure the assembly (see Figure 3-4). Make sure to handle the cards by the edges and shields to prevent contamination.

2. Facing the rear panel of the Model 7001, select the slot (CARD 1 or CARD 2) that you wish to install the card in.

3. Referring to Figure 3-13, feed the multiplexer card assembly into the desired slot such that the edges of the relay card ride in the rails.

4. With the ejector arms in the unlocked position, push the card assembly all the way into the mainframe until the arms engage into the ejector cups. Then

push both army inward to lock the card into the

mainframe.

5. Tighten the thumb screw shown in Figure 3-13.

CAUTION

To prevent contamination to the multiplexer card that could degrade per-

formance, only handle the card assembly by the edges and shields.

Multiplexer card installation

Perform the following steps to install the multiplexer card assembly in the Model 7001 mainframe:

WARNING

Tighten the thumb screw to ensure proper chassis ground.

Multiplexer card removal

To remove the multiplexer card assembly, first loosen the thumb screw shown in Figure 3-13, then unlock the card by pulling the latches outward, and pull the card assembly out of the mainframe. Remember to handle the card assembly by the edges and shields to avoid contamination that could degrade performance.

3.12

-t- Ejector Arms

(2)

WARNING: Tighten the thumb screw

to ensure proper chassis ground.

Figure 3- 73

7074

card installation in Model 7007

3.13

3-14

Operation

4.1

The information in this section is formatted as follows:

4.2

4.3

4.4

4.5

Introduction

dower limits: Summarizes the maximum power limits of the Model 7014 multiplexer card assembly.

Mainframe control of multiplexer card: Summarizes programming steps to control the multiplexer card from the Model 7001 Switch System mainframe.

Multiplexer switching examples: Provides some typical applications for using the Model 7014.

Measurement considerations: Reviews a number of considerations when using the Model 7014 to make measurements.

4.2 Power limits

CAUTION

To prevent damage to the card, do not

exceed the maximum signal level specifications of the card.

Maximum signal h&

DC signals:

AC signals:

4.3

Mainframe control of multiplexer

1lOV between any two pins (terminals), 1A switched, 30VA (resistive load).

125V rms or 175V AC peak bctween my two pins (terminals), 1A switched, 6OVA (resistive load).

card

The following information pertains to the Model 7014 multiplexer card. It assunws that you are familiar with the operation of the Model 7001 mainframe.

If you are not familiar with the operation of the mainframe, it is recommended that you proceed to Getting

Started (Section 3) of the Model 7001 Instruction Manual after reading the following information.

4.3.1 Channel assignments

The Model 7001 has a channel status display (Figure 4

1) that provides the real-time state of each available

channel. The left portion of the display is for slot 1

(Card l), and the right portion is for slot 2 (Card 2).

To prevent overheating oi- damage to the relays, never exceed the following maximum signal levels:

Multiplexer organization of the channel status display for each slot is shown in Figure 4-2. The card contains

4-1

channels and is made up of four banks (Bank A, B, tor and mux input are separated by exclamation points C, and D) of 10 multiplexer inputs as shown in the illustration.

(!). Some examples of CHANNEL assignments are as

follows:

To control a multiplexer (mux) card from the mainframe, each multiplexer input must have a unique CHANNEL assignment, which includes the slot numher that the card is installed in. The CHANNEL assignments for a multiplexer card are provided in Figure 4-

3. Each CHANNEL assignment is made up of the slot designator (1 or 2) and the multiplexer channel. To be consistent with Model 7001 operation, the slot designa-

7001 Display

CARD1

: : .

....................

....... .....................

. = Open Channel

. . . . . = Closed Channel

2 : : :

............... ............

: .B : . : : : : :

CHANNEL 1!2 = Slot 1, Channel 2 (Input 2 of Bank A) CHANNEL 1!40 = Slot 1, Channel 40 (Input 10 of Bank

D) CHANNEL 2!23 = Slot 2, Channel 23 (Input 3 of Bank

C) CHANNEL 2!36 = Slot 2, Input 36 (Input 6 of Bank D)

CARD

: I .B .9 ,

Figure 4-7 Channel status display

I, 12

BankB

’

21 22

BankC

’

31 32

BankD

’

Figure4-2 Display organization for multiplexer channels

13 14

23 24

33 34

15 16

35 36

17 16

19 20

27 26 29

37 36

39 40

4-2

Examples : I!18 = Slot 1, Channel 16

2!36 = Slot 2, Channel 36

Figure 4-3

Model 71114 programming channel assignments

4.3.2 Front panel control

Closing and opening channels

Amultiplexer channel is closed from the front panel by simply keying in the CHANNEL assignment and pressing CLOSE. For example, to close channel 36 (Input 6 of Bank D) of a multiplexer card installed in slot 2, key in the following channel list and press CLOSE:

SELECT CHANNELS 2!36

The above closed channel can be opened by pressing

OPEN or OPEN ALL. ‘The OPEN key opens only the charnels specified in the channel list, and OPEN ALL opens all channels.

The following display is an example of a channel list that consists of several channels:

SELECT CHANNELS 2!1,2!3,2!22-2!25

Notice that channel entries are separated by commas (,). Acomma is inserted by pressing ENTER or the right cursor key D The channel range is specified by using the hyphen (-) key to separate the range limits. Pressing CLOSE will close all the channels specified in the channel list. Pressing OPEN (or OPEN ALL) will open the channels.

Scanning channels

Multiplexer channels are scanned by creating a scan list and configuring the Model 7001 to perform a scan. The scan list is created in the same mnnner as a channel list (see Closing and Opening Channels). However, the

scan list is specified from the “SCAN CHANNEL” dis-

play mode. (The SCAN LIST key toggles between the

channel list and the scan list.) The following shows an example of a scan list:

SCAN CHANNELS 2!1,2!3,2!21-2!25

4-3

Operation

When a scan is performed, the channels specified in the scan list will be scanned in the order that they are pre sented in the scan list.

A manual scan can be performed by using the RESET default conditions of the Model 7001. RESETis selected

from the SAVESETUP menu of the main MENU. When RESET is performed, the mainframe is configured for an infinite number of manual scans. The first press of

STEP takes the mainframe out of the idle state. l%e next press of STEP will close the first channel specified in the scan list. Each subsequent press of STEP will select the next channel in the scan list.

4.3.3 IEEE-488 bus operation

Bus operation is demonstrated using HP BASIC 4.0. The programming statements assume that the primary address of the mainframe is 07.

Closing and opening channels

The following SCPI commands are used to close and open channels:

:CLOSe <list>

:OPEN <list> I ALL

The following statement closes channels l!l, and 1!3

through l!ll:

tle as four commands. These commands are listed as follows:

*RST :TRIGger:SEQuence:COUNt:AUTo ON” :ROIJTe:SCAN <list> :INIT

The first command resets the mainframe to a default scan configuration. The second command automatically sets the channel count to the number of channels in the Scan List, the third command defines the Scan List and the fourth command takes the Model 7001 out of the idle state.

The following program will perform a single scan through all 40 channels of a multiplexer card installed in slot 1:

OUTPUT 707; “*RST” 20 OUTPUT 707; “:trig:seq:coun:auto on” 30 OUTPUT 707; “xan (6% 1!1:1!40)” 40 OUTPUT 707; “:init” 50 END

Line 10 Selects a default configuration for the scan. Line 20 Sets channel count to the scan-list-length. Line 30 Defines the scan list. Line 40 Take the Model 7001 out of the idle state. The

scan is configured to start as soon as this command is executed.

OUTPUT 707; “:clos (@ l!l, 1!3:1!11)”

Notice that the colon (:) is used to separate the range limits.

Either of the following statements will open channels

l!l, and 1!3 through l!ll:

OUTPUT 707; “:open (@ l!l, 1!3:1!11)”

OUTPUT 707; “:open all”

Scanning channels

There are many commands associated with scanning. However, it is possible to configure a scan using as lit-

4-4

When the above program is run, the scan will be completed in approximately 240 milliseconds (3msec delay for each relay close and a 3msec delay for each open), which is too fast to view from the front panel. An additional relay delay can be added to the program to slow down the scan for viewing. The program is modified by adding line 25 to slow down the scan. Also, Line 5 is added to the beginning of the program to ensure that all channels are open before the scan is started.

5 OUTPUT 707; “:open all” 10 OUTPUT 707; “*RST” 20 OUTPUT 707; “:trig:seq:coun:auto on” 25 OUTPUT 707; “:trig:delO.25” 30 OUTPUT 707; “:scan (6%~ 1!1:1!40)” 40 OUTPUT 707; “:init”

50 END

Line 5 Opens all channels. Line 25 Sets a % second delay after each channel

Cl”S”S.

The Model 2001 is configured for thermocouple readings with the thermocouple type, reference junction channel, temperature coefficient, and voltage offset. These parameters are entered from its front panel or programmed from the IEEE-488 bus. See the Model 2001 Operator’s Manual for details.

4.4 Multiplexer switching

This paragraph presents some typical applications for the Model 7014. These include thermocouple scanning, resistor testing, and transistor testing.

CAUTION

Do not switch a current or voltage

source to Channel 1 of the Model

7014. The temperature sensor of the reference junction doea not have input protection. Specify Channel 1 as a “restricted channel” from the Model 7001 CONFIGURE SCAN menu so that it cannot be closed, except when switching thermocouples.

examples

4.4.1 Thermocouple scanning

A test system to scan thermocouples consists of one or more thermocouple cards in a switching mainframe and a DMM, as shown in Figure 4-4. A multimeter with a temperature function, such as the Model 2001, is described because it derives temperature values from voltage readings.

4.42 Resistor testing

The Model 7014 can be used to test a large number of resistors using only one test instrument or group of instruments. Such tests include two-wire and four-wire resistance measurements using a DMM, and low-resistance measurements using a current source and scnsitive digital volhneter, as discussed in the following paragraphs.

Two-wire resistance tests Figure 4-5 shows a typical test setup for making two-

wire resistance measurements. The Model 7014 card provides the switching function, while the resistance measurements are made by a Model 199 DMM. Since only two-pole switching is required for this application, one Model 7014 card can be used to switch up to 39 resistors (additional multiplexer banks can be added, if desired, by adding more cards).

Accuracy of measurements can bc optimized by minimizing stray resistance.

Trigger signals are used to synchronize Model 7001

channel closures and Model 2001 measurements. In addition to BNC connections for external triggering, the

Models 7001 and 2001 have a high-speed trigger link

for controlling up to six instruments.

Make connecting wires as short as possible to minimize path resistance. Another technique is to short one of the multiplexer inputs, close the shorted channel and then enable the DMM zero feature to cancel path resistance. Leave zero enabled for the entire test.

4-5

Operation

Figure4-4

Thermocouple scanning

4-6

Single 1x39 MUX DUTs

r---i r---i r---i

(39)

paired with Channel 21 in the 4.~01~

mode. Specify Channel 1 as a “rcstrict-

ed channel” from the Model 7001 CONFIGURE SCAN menu so that it cannot be closed.

The Model 7014 can be configured for 19 channels of 4. pole operation by isolating Banks A and B from Banks C and D, and by programming the Model 7001 mainframe for 4-pole mode. The resulting paired channels are shown in Table 4-1.

Four-wire resistance tests

More precise measurements over a wider range of sys-

tem and DUT conditions can be obtained by using the four-wire measurement scheme shown in Figure 4-6. Here, separate sense leads from the Model 196 DMM are routed through the multiplexer to the resistor under test. The extra set of sense leads minimizes the effects of voltage drops across the test leads. Note, however, that an extra two poles of switching are required for each resistor tested. For this reason, only 19 resistors per card can be tested using this configura-

tion.

NOTE

Since Channel 1 of the Model 7014 is the reference junction, it cannot be

Figure 4-6

4.wire

resistance

testing

4-7

operation

Table 4- 1

Paired Channels in 4-p& Operation

7001

channel

assignment

Channel

pair in

4-pole

and 22

BankA,InZand Bank C, In 2

and 23

Bank A, In 3 and Bank C, In 3

and 24

Bank A, In 4 and Bank C, In 4

and 25

Bank A, In 5 and Bank C, In 5

and 26

and 27

Bank A, In 6 and

Bank C, In 6 Bank A, In 7 and

Bank C, In 7

8 Sand28 lBankA,In8and ~

Bank C, In 8

9and29

Bank A, In 9 and Bank C, In 9

10 and 30

Bank A, In 10 and Bank C, In 10

11 and 31

Bank B, In 1 and Bank D, In 1

~ 12 and 32

Bank B, In 2 and BankD,InZ

13 and 33

Bank B, In 3 and Bank D, In 3

and 34

Bank B, In 4 and

Bank D, In 4

and 35

Bank B, In 5 and BankD,In5

and 36

Bank B, In 6 and Bank D, In 6

and 37

Bank B, In 7 and

Bank D, In 7

18 and 38

BankB,In8and Bank D, In 8

19 and 39

Bank B, In 9 and BankD,In9

2.0

20 and 40

Bank B, In 10 and Bank D, In 10

Connection

designations

Bank jumper removal is described in paragraph 3.3.1. To configure the connector card for 4-p& operation, only remove the jumpers between Banks B and C

(W203

and W204).

Selecting 4-pole operation for a Model 7001 card slot is discussed in Section 4 of the Model 7001 Instruction Manual. After the 4-p& mode is selected, the Model 7001 mainframe will display just 20 channels for the chosen card slot. Each closed channel will also close its paired channel on the card.

Although the four-wire connection scheme minimizes problems caused by voltage drops, there is one other potentially troublesome area associated with low resistance measurements: thermal EMFs caused by the i-elay contacts. In order to compensate for thermal EMFs, the offset-compensated ohms feature of the Model 196 DMM should be used. To use this feature, short the HI and LO terminals of one of the bank inputs, then close the relay. Enable zero on the Model 196, then select offset-compensated ohms.

Low-level resistance measurements

Many times, it is necessary to make resistance measurements with either lower voltage sensitivity or higher currents than are available with ordinary DMMs. Examples of cases where low-level resistance measurements may be necessary include the testing of PC board traces, contacts, bus bars, and low resistance shunts.

Figure 4-7 shows a typical test configuration for a

switching system capable of testing a number of low resistance devices. The Model 220 Current Source forces current through the device under test, while the Model 182 Sensitive Digital Voltmeter measures there-

salting voltage across the device.

Since low voltage levels are being measured, thermal EMF offsets generated by relay and connector contacts will have a detrimental effect on measurement accuracy unless steps are taken to avoid them (the Model 7014

has been designed to keep relay EMF at a minimal lev-

el). Thermal EMF effects can be virtually eliminated by

taking two voltage measurements, El and E,, the first

with tlw current, I, flowing in one direction, and the second with a current, I, of the same magnitude flow-

4-8

ing in the opposite direction. The resistance can then be calculated as follows:

E,-E,

R=-

Note that simply reversing the current source polarity will result in a 2x accuracy specification change. To avoid this problem, matrix switching could be added

to the test system to reverse the current.

Figure 4-7 Low resistance

testing

4-9

Operation

4.4.3 Transistor testing:

Typical transistor tests that can be performed with the aid of the Model 7014 include current gain tests, leakage tests, as well as tests to determine the common-

emitter characteristics of the device. The following paragraphs discuss these tests and give typical equipment configurations for the tests.

Current

The DC or static common-emitter current gain of a transistor can be determined by biasing the transistor for a specific value of base current, IB, and then measuring the collector current, E. The DC common-emitter current gain, p, of the transistor is then determined

as follows:

Figure 4-8 shows the test configuration and equivalent circuit for the current gain test. The Model 224 Current

Source is used to source the base current, IB, The Model 230 Voltage Source supplies the collector-emitter voltage, VCE, and the collector current, F, is measured by

the Model 196 DMM. Switching among the transistors being tested is, of course, performed by the Model 7014 multiplexer card.

In order to perform the current gain test, the voltage source is first set to the desired value of VCB The current source is then set to a base current value that will

result in the desired value of k as measured by the

DMM. The current gain can then be calculated as out-

lined above.

gain tests

For example, a resistor that measures exactly 10061 at 25°C with a temperature coefficient of 100ppm/“C should not change more than 1OmR per “C of temperature change. That resistor measured at 35°C should read between 99.900 and lOO.lOOR (lOOn +lOOmQ.

Temperahwe coefficient is calculated from the following equation:

TC = (AR) (lob)

(RI (AT)

where:

TC = temperature coefficient in ppm/‘C AR = change in resistance (reference resistance

test resistance) R = actual resistance at the reference temperature AT = change in temperature (reference tempera-

ture - test temperature)

Typically, several samples of a particular resistor from a vendor will be tested to verify the specifications. The temperature coefficient is usually checked at several temperature points to ensure its integrity over a range of temperatures.

Evaluation of resistors can be done with a Model 7014 card in a Model 7001 mainframe, along with a Model 2001 multimeter to make temperature and 4-terminal resistance measurements. Temperature coefficients are calculated with respect to the resistance measurement made at a reference temperature. Thermal EMFs gene ated by connections in the test circuit are cancelled by the offset compensated ohms feature of the Model

2001.

In order to reduce errors caused by voltage burden, use a higher current range on the Model 196 DMM. Doing so will result in the loss of one or two decades of resolution, but 3% or 4M-digit resolution will probably be adequate for most situations.

4.4.4 Resistor temperature coefficient testing

Temperature coefficient is the rate of change of resistance with respect to temperature, typically expressed as ppm/“C (parts per million per degree centigrade).

4.10

Figure 4-8 shows a system that can test accuracy and temperature coefficient of up to 29 resistors that have the same specifications (resistance and temperature coefficient.

For further information on resistor temperature coefficient testing, see the following reference:

Simplified Resistor Temperature Coefficient Test Systern Using Model 196. Keithley Instruments, AppIication Note 811, 1987.

A. Test Configuration

8. Simplified Equivalent Circuit

Figure 4-8 Configuration for current gain and common-emitter test

4.11

Figure 4-9 Resistor temperature coefficient testing

r----

4.12

Common-emitter characteristic tests

Common-emitter characteristics are determined bv setting the base current, I,, to specific values. At each 1; value, the collector-emitter voltage, VCE, is swept across the desired ranee at soecific intervals. and the collector current, I,, is then measured. When the data are plotted, the result is the familiar family of commonemitter curves (Figure 4-10).

4.5.1 Thermocouple measurement error

sources

The reference accuracy specification of the Model 7014 is the sum of the following error sources:

* Reference junction sensor error

l Temperature gradient across the card

The same test configuration that is used for current gain tests can be used for measuring common-emitter characteristics. The Model 224 is used to set the base current, IB, to the desired values. The Model 230 Voltage Source provides the collector-emitter voltage, VCE, and the Model 196 DMM measures the collector current, Ic.

l Relay self-heating

You can achieve better card performance by understanding how these error sources contribute to the specification. The reference junction temperature and its associated circuitry are shown in Figure 3-6.

Reference junction sensor

The primary factor determining reference junction accuracy is the operating temperature. By using the Model 7014 in the 18°C to 28°C range, maximum sensor

perf”rmance is achie”ed,

A temperature gradient of 0.32”C develops across the connector board (*O.l6”C on each side of the sensor). This gradient contributes to the rcfcrence error.

1 2 3 4 5

VCE , volts

Figure 4-10

Typical common-emitter characteristics

4.5 Measurement considerations

Many measurements made with the Model 7014 are subject to various effects that can seriously affect lowlevel measurement accuracy. The following paragraphs discuss these effects and ways to minimize them.

Channels that are close to the sensor have the least temper&we gradient error (channels 5,6, 15, 16,25,26,35,

and 36); channels farthest away have the most temper-

ature gradient error (channels 2 and 40).

When making relative tcmperaturc measurements and not absolute measurements, it is advantageous to use

adjacent channels, as follows:

l Adjacent channels on the same terminal block (e.g.,

channels 2 and 3) will have no more than 0.035”C error behveen them.

l Adjacent channels on different terminals block

(e.g., channels 15 and 25) will have no more than

0.05T

a-i-Oi-

4.13

Operation

Relay self-heating

As channels are turned on, heat is dissipated from the relay coils. This can cause a measurement error up to

0.08”C. The following considerations reduce this error:

l Close only one channel at a time. (The single-chan-

nel mode of the Model 7001 can be used to prevent

the simultaneous closure of multiple channels.)

l Keep channel closure time to a minimum. (Worst

case is with a relay closed for five minutes.)

l Use the relays closest to the sensor. (Worst cases are

channels 1, 10, 11,20,21,30,31, and 40.)

l Do not mix switching applications simultaneously,

for example, thermocouple and high energy switching. The card’s reference accuracy will be affected due to relay contact heating.

Other error sources

4.5.2 Path isolation

The path isolation is simply the equivalent impedance

between any two test paths in a measurement system.

Ideally, the path isolation should be infinite, but the actual resistance and distributed capacitance of cables and connectors results in less than infinite path isolation values for these devices.

Path isolation resistance forms a signal path that is in parallel with the equivalent resistance of the DUT, as

shown in Figure 4-11. For low-to-medium device resis-

tance values, path isolation resistance is seldom a consideration; however, it can seriously degrade measurement accuracy when testing high-impedance devices. The voltage measured across such a device, for example, can be substantially attenuated by the voltage divider action of the device source resistance and path isolation resistance, as shown in Figure 4.12. Also, leakage currents can be generated through these resistances by voltage sources in the system.

Thermocouple wire-In most cases, the major source of error is the thermocouple wire. For the standard grade of type K thermocouple wire, the error is 2.2”C or

0.75%, whichever is greater. For the special grade of type K wire, the error is l.l’C or 0.4% error.

Offset voltage-The primary source of offset voltage is the contact potential of the relay, typically <5OOnV Due to self-heating of the relay, the offset voltage could

be 1pV if a channel is closed for five minutes. For a type

K thermocouple, 1pV offset produces 0.024”C of error.

Measurement instrument - The voltage measurement accuracy and temperature conversion algorithm determine the accuracy of the instrument. The Model

2001 Multimeter has these parameters combined into

one temperature specification. For type K thermocou-

ples, the Model 2001 has 0.5”C accuracy.

Air drafts - For optimum performance, the card should be protected from drafts. Air currents can cause a temperature fluctuation under the connector card’s isothermal cover.

Row = Source Resistance of DUT Eoui = Source EMF of DUT

RPATH = Path Isolation Resistance

RIN = Input

Figure 4- 11 Path isolation

Resistance of Measuring

resistance

Instrument

Any differential isolation capacitance affects DC measurement settling time as well as AC measurement accuracy. Thus, it is often important that such capacitance be kept as low as possible. Although the distributed ca-

4.14

pacitance of the matrix card is generally fixed by de-

sign, there is one area where you do have control over

the capacitance in your system; the connecting cables. To minimize capacitance, keep all cables as short as possible

At high current levels, even a single conductor can gencrate significant fields. These effects can be minimized by using twisted pairs, which will cancel out most of

the resulting fields.

Rour

Eour RPATH

Rour + RPATH

Figure 4- 12

Voltage

attenuation bypath isolation resistance

Eour =

4.5.3 Magnetic fields

When a conductor cuts through magnetic lines of force, a very small current is generated. This phenomenon will frequently cause unwanted signals to occur in the test leads of a switching matrix system. If the conduc-

tor has sufficient length, even weak magnetic fields like those of the earth can create sufficient signals to affect low-level measurements.

4.5.4 Radio frequency interference

RF1 (Radio Frequency Interference) is a general term used to describe electromagnetic interference over a wide range of frequencies across the spectrum. Such RF1 can be particularly troublesome at low signal lcvels, but is can also affect measurements at high levels if

the problem is of sufficient severity.

RF1 can be caused by steady-state sources such as radio or TV signals, or some types of electronic equipment

(microprocessors, high speed digital circuits, etc.), or it can result from impulse sources, as in the case of arcing in high-voltage environments. In either case, the effect on the measurement can be considerable if enough of

the unwanted signal is present.

RF1 can be minimized in several ways. The most obvious method is to keep the eauiument and sirnal leads as far away from the RF1 source as possible. Shielding the switching card, signal leads, sources, and mcasuring instruments will often reduce RF1 to an acceptable level. In extreme cases, a specially-constructed scrc‘en room may be required to sufficiently attenuate the troublesome signal.

. .

Two ways to reduce these effects are: (1) reduce the lengths of the test leads, and (2) minimize the exposed circuit area. In extreme cases, magnetic shielding may be required. Special metal with high permeability at low flux densities (such as mu metal) is effective at re-

ducing these effects.

Even when the conductor is stationary, magnetically-

induced signals may still be a problem. Fields can be

produced by various signals such as the AC power line

voltage. Large inductors such as power transformers can generate substantial magnetic fields, so care must be taken to keep the switching and measuring circuits a good distance away from these potential noise sources.

Many instruments incorporate internal filtering that may help to reduce RF1 effects in some situations. In some cases, additional external filtering may also bc re-

quired. Keep in mind, however, that filtering may have

detrimental effects on the desired signal.

4.5.5 Ground loops

When two or more instruments arc connected together,

care must be taken to avoid unwanted signals caused by ground loops. Ground loops usually occur when

sensitive instrumentation is connected to other instru-

mentation with more than one signal return path such

as power line ground. As shown in Figure 4-13, tbc re-

sulting ground loop causes current to flow through the

instrument LO signal leads and then back through

power line ground. This circulating current develops a small but undesirable voltage between the LO terminals of the two instruments. This voltage will be added to the source voltage, affecting the accuracy of the mea-

Ground loops are not normally a problem with in&-umats having isolated LO terminals. However, all instruments in the test setup may not be designed in this manner. When in doubt, consult the manual for all instrumentation in the test setup.

4.5.6 Keeping connectors clean

As is the case with any high-resistance device, the integrity of connectors can be damaged if they are not handled properly. If connector insulation becomes contaminated, the insulation resistance will be substantially reduced, affecting high-impedance measurement P&S.

Figure 4-13 Power line ground loops

Figure 4-14 shows how to connect several instruments together to eliminate this type of ground loop problem. Here, only one instrument is connected to power line ground.

Figure 4- 14 Eliminating ground loops

Oils and salts from the skin can contaminate connector insulators, reducing their resistance. Also, contaminants present in the air can be deposited on the insulator surface. To avoid these problems, never touch the connector insulating material. In addition, the multiplexer card should be used only in clean, dry environments to avoid contamination.

If the connector insulators should become contaminated, either by inadvertent touching, or from air-borne deposits, they can be cleaned with a cotton swab dipped in clean methanol. After thoroughly cleaning, they should be allowed to dry for several hours in a low-humidity environment before use, or they can be dried more quickly using dry nitrogen.

4.5.7 AC frequency response

The AC frequency response of the Model 7014 is important in test systems that switch AC signals. Refer to the specifications at the front of this manual.

4.16

Service Information

WARNING

The information in this section is intended only for qualified service personnel. Some of the procedures may expose you to hazardous voltages that could result in personal injury or death. Do not attempt to perform these procedures unless you are qualified to do so.

5.1 Introduction

This section contains information necessary to service the Model 7014 multiplexer card and is arranged as follows:

5.2 Handling and cleaning precautions: Discusses handling precautions and methods to clean the card should it become contaminated.

5.3 Performance verification: Covers the procedures necessary to determine if the card meets stated specifications.

5.4 Calibration: Describes calibrating the card to its specified temperature accuracy.

5.5 Special handling of static-sensitive devices: Reviews precautions necessary when handling static-sensitive devices.

5.6 Principles of operation: Briefly discusses circuit operation.

5.7 Troubleshooting: Presents s”me troubleshooting tips for the Model 7014 including relay replacement precautions.

5.2 Handling and cleaning precautions

Because of the high-impedance areas on the Model 7014, care should be taken when handling or servicing the card to prevent possible contamination. The following precautions should be taken when servicing the card.

Handle the card only by the edges and shields. Do not touch any board surfaces or components not associated with the repair. Do not touch areas adjacent to electrical contacts. When servicing the card, wear clean cotton gloves.

Do not store or operate the card in an environment where dust could settle on the circuit board. Use dry nitrogen gas to clean dust off the board if necessary.

Should it become necessary to use solder on the circuit board, use an OA-based (organic activated) flux. Remove the flux from the work areas when the repair has been completed. Use pure water along with clean cot-

ton swabs or a clean soft brush to remove the flux. Take care not to spread the flux to other areas of the circuit board. Once the flux has been removed, swab only the repaired area with methanol, then blow dry the board with dry nitrogen gas.

After cleaning, the card should be placed in a 50°C low humidity environment for several hours before use.

5.3

Performance verification

CAUTION

Do not switch a current or voltage so”rce to Channel 1 of the Model

7014. The temperature sensor of the reference junction does not have input protection. Specify Channel 1 as a “restricted channel” from the Model 7001 CONFIGURE SCAN menu so that it cannot be closed, except when scanning thermocouples.

conditions do not apply if the backplane jumpers are removed.

CAUTION

Contamination will degrade the performance of the card. To avoid contamination, always grasp the card by the side edges. Do not touch the connectors, and do not touch the board surfaces or components. On plugs and receptacles, do not touch areas adjacent to the electrical contacts.

NOTE

Failure of any performance verification test may indicate that the multiplexer card is contaminated. See paragraph 5.2 to clean the card.

5.3.1 Environmental conditions

The following paragraphs discuss performance verification procedures for the Model 7014, including path resistance, offset current, contact potential, and isola-

tion.

With the Model 7014’s backplane jumpers installed, the performance verification procedures must be performed with only one multiplexer card (the one being checked) installed in the Model 7001 mainframe. These

All verification measurements should be made at an ambient temperature between 18” and X’C, and at a

relative humidity of less than 70%.

5.3.2 Recommended equipment

Table 5-1 summarizes the equipment necessary for performance verification, along with an application for each unit.

5-2

Table 5-1

Verification

and

calibration

equipment

Description

Model or part

Electrometer w/voltage source Keithley Model 617

Sensitive Digital Voltmeter

Keithley Model 182 Triax cable (unterminated) Low thermal cable

(unterminated) Thermistor probe

Reference thermometer

Distilled water ice bath (Dewar flask or Thermos)

Specifications

300R; 0.01 %I

300mV; 0.008% lOpA, I OOpA;

1.6% 1OOV source;

0.2% 3mV; 6Oppm

*O.l”C

Applications Path resistance

Reference junction Offset current, path isolation

contact potential Offset current Contact potential

Reference junction, calibration

Calibration

5.3.3 Reference junction test

This procedure verifies that the card is operating within its temperature specification. A Model 7001 Switch System is used to close Channel 1 of the card.

1. Turn on a Model 1~96 and set it to the 300mVDC range. Short the test leads together. Zero the multimeter after the thermals have stabilized (two hours if from cold-start). A Model 2001 can be used on the 200mVDC range; let it warm up for one hour.

2. Set up the test equipment as shown in Figure 5-l and let it warm up one hour. Remove the cover of the Model 7001 as explained in paragraph 7.5 of the Model 7001 Instruction Manual. Insert a Model 7014 card and protect it from air drafts.

Use a probe with a specified accuracy of +O.O05”C.

The

combination of the probe and reference ther-

mometer should be accurate to +O.OlYI.

3. Coat the probe with a thermally conductive compound and insert it into the 0.110” hole marked “CAL” in the isothermal cover.

4. Use the Model 7001 front panel to close Channel l!l.

5. Take a reading from the reference thermometer. Use the following equation to calculate the equivalent reference junction output voltage (VREJ:

VKFF = (T, +273.15) x 0.0002

6. Read the voltage across the output of Bank A. Compare the measured and calculated voltages. If they differ by more than 52wV (0.26”C). perform the calibration procedure of paragraph 5.4.1.

5-3

Figure 5-1 Reference junction test

5-4

Scrv& Information

5.3.4 Channel resistance tests

Perform the following steps to verify that each contact of every relay is closing properly and that the resistance is within specification.

1. Turn off the Model 7001 if it is on.

2. Turn on the Model 196, and allow it to warm up for one hour before making measurements.

3. Connect all input terminals of Bank A together to form one common terminal, as shown in Figure 5-

Set the Model 196 to the 300R range and connect the four test leads to the OHMS and OHMS SENSE input jacks.

5. Short the four test leads together and zero the Model 196. Leave zero enabled for the entire test.

Connect OHMS HI and OHMS SENSE HI of the Model 196 to the common terminal (jumper on Bank A inputs). It is recommended that the physical connections be made at inputs 2 and 10 of Bank A, as shown in Figure 5-2.

7. Connect OHMS LO and OHMS SENSE LO to the HI (H) terminal of Bank A.

8. Install the Model 7014 in slot 1 (CARD 1) of the Model 7001.

Turn on the Model 7001 and program it to close

Channel 1!2 (Bank A, Input 2). Verify that the resistance of this path is <IQ.

10. Open Channel 1!2 and close Channel 1!3 (Bank A, Input 3). Verify that the resistance of this path is <1 Q.

11. Using the basic procedure in steps 9 and 10, check the resistance of Bank A HI (H) terminal paths for Inputs4 through 10 (Channels 1!4 through l!lO).

12. Turn off the Model 7001 and move the OHMS LO and OHMS SENSE LO test leads to the LO (L) terminal of Bank A.

13. Repeat steps 9 through 11 to check the LO (I.) terminal paths of BankA(Channels 1!2 through l!lO).

14. Repeat the basic procedure in steps 1 through 13

for Banks B through D (Channels 1!11 through 1!40).

Figure 5-2 Path resistance test connections

Model 7014

s-5

5.3.5 Offset current tests

These tests check leakage current between HI (H) and LO (L) (differential offset current) and from HI (H) and LO (L) to chassis (common-mode offset current) of each pathway. In general, these tests are performed by

simply measuring the leakage current with an electrometer. In the following procedure, the Model 617 is used to measure the leakage current. Test connections are shown in Figure 5-3.

Perform the following procedure to check offset current:

1. Turn off the Model 7001 if it is on, and remove any jumpers or wires connected to the multiplexer

card.

2. Connect the triax cable to the Model 617, but do not connect it to the multiplexer card at this time.

3. Turn on the Model 617 and allow the unit to warm

up for two hours before testing. After warm up, select the ZOOpA range, and enable zero check and zero correct in that order. Leave zero correct enabled for the entire procedure. Also, be certain that V-Q, GUARD is OFF and ground strap is connected to LO.

4. Connect the triax cable to Bank A HI and LO, as

shown in Figure 5.3A.

5. Install the Model 7014 in slot 1 (CARD 1) of the Model 7001.

6. Turn on the Model 7001 and program the unit to

close Channel 1!2 (Bank A, Input 2).

7. On the Model 617, disable zero check and allow the reading to settle. Verify that the reading is <lOOpA. This specification is the offset (leakage) current of the pathway.

8. Enable zero check on the Model 617 and open Channel 1!2 from the front panel of the Model

7001.

9. Repeat the basic procedure in steps 6 through 8 to check the rest of the pathways (Inputs 3 through

10) of Bank A (Channels 1!3 through l!lO).

10. Turn off the Model 7001 and change the electrometer connections to Bank B.

11. Repeat the basic procedure in steps 6 through 10 to check Bank B, Inputs 1 through 10 (Channels l!ll

through 1!20).

12. Repeat the basic procedure in steps 6 through 11

for Banks C and D (Channels 1!21 through 1!40).

13. Turn off the Model 7001 and change the electrome-

ter connections, as shown in Figure 5-3B. Note that electrometer HI is connected to HI and LO of the Bank A output, which are jumpered together. Electrometer LO is connected to chassis.

14. Repeat steps 6 through 12 to check that the common mode offset current is <lOOpA.

5-6

Model 7014

A) Differential

Model 7014

6) Common-Mode

Figure S-3 Differential offset current te5t connections

5-7

Service Information

5.3.6 Contact potential tests

These tests check the EMF generated by each relay contact pair (H and L) for each pathway. The tests simply consist of using a sensitive digital voltmeter (Model

182) to measure the contact potential. See Figure 5-4.

Perform the following procedure to check contact po-

tential of each path:

1. Turn off the Model 7001 if it is on.

2. Place jumpers between Banks A-B, B-C, and C-D.

3. Turn on the Model 182 and allow the unit to warm up to achieve rated accuracy.

4. Place a short between HI to LO on each input (Channels 2-40).

5. Place a short between HI to LO on output Bank D (long enough to cut with wire cutters).

6. Connect the Model 182 input leads to HI and LO

output Bank A using copper wires.

7. Install the Model 7014 in the Model 7001 slot 1, and turn on the Model 7001.

8. Allow Models 7001, 7014 and 182 to warm up for

two hours.

9. Select the 3mV range on the Model 182.

10. Press REL READING (on the Model 182) to null out internal offsets. Leave REL READING enabled for the entire procedure.

11. Turn off the Model 7001. Remove the Model 7014 from slot 1. Cut the short on B and D output HI to LO.

12. Install the Model 7014 in the Model 7001 slot 1, and turn power on.

13. Wait 15 minutes.

14. Program the Model 7001 to close Channel 1!2.

15. After settling, verify that reading on the Model 182 is +V. This measurement represents the contact potential of the pathway.

16. From the Model 7001, open Channel 1!2.

17. Repeat steps 12 through 14 for all 39 channels.

Figure 5-4

Contact

5-8

poW2ntial

Model 7014

test connections

Service Information

5.3.7 Bank and channel-to-channel isolation tests

Bank isolation tests check the leakage resistance between adjacent banks. Channel-to-channel isolation tests check the leakage resistance between a Bank Output connection and a Bank Input connection with an adjacent Bank Input relay closed. In general, the tests are performed by applying a voltage (1OOV) across the leakage resistance and then measuring the current. The isolation resistance is then calculated as R = V/I. In the following procedure, the Model 617 functions as both a voltage source and an ammeter. In the V/I function, the Model 617 internally calculates the resistance from the known voltage and current levels and displays the resistive value.

Perform the following steps to check bank and chan-

nel-to-channel isolation:

1. Turn off the Model 7001 if it is on, and remove any Farda or test leads connected to the multiplexer

2. Turn on the Model 617 and allow the unit to warm up for two hours before testing.

3. On the Model 617, select the 2pA range, and enable zero check and zero correct in that order. Leave zero correct enabled for the entire procedure.

4. Connect the electrometer to the Model 7014, as shown in Figure 5-5.

5. Install the Model 7014 in slot 1 (CARD 1) of the Model 7001 and turn on the mainframe.

6. On the Model 617, select the 20pA range and re-

lease zero check.

7. On the Model 617, press SUPPRESS to cancel offset

current, then enable zero check.

WARNING

The following steps use high voltage

(1OOV). Be sure to remove power from the circuit before making connection changes.

8. On the Model 617, set the voltage source for +lOOV, and select the 20nA current range. Make sure the voltage source is in standby.

9. Place the Model 617 in the V/I measurement function by pressing SHIFT OHMS.

10. Program the Model 7001 to close Channels 1!2 and 1!13 (Bank A, Input 2 and Bank B, Input 3).

Figure 5-5 Bank isolation test connections

5-9

Service

information

11. On the Model 617, disable zero check and press OPERATE to source +lOOV.

12. After allowing the reading on the Model 617 to settle, verify that it is >lGB (1090). This measurement is the leakage resistance (bank isolation) between

Bank A, Input 2 and Bank B, Input 3.

13. Place the Model 617 voltage source in standby and

enable zero check.

14. Turn off the Model 7001 and move the electrometer

connections to Banks B and C.

15. Install the Model 7014 in slot 1 of the mainframe

and turn on the Model 7001.

16. Program the Model 7001 to close Channels l!ll and 1!22 (Bank 8, Input 1 and Bank C, Input 2).

17. On the Model 617, disable zero check and press OPERATE to source +lOOV.

18. After allowing the reading on the Model 617 to settle, verify that it is >lGQ (109Q).

19. Place the Model 617 voltage source in standby and enable zero check.

20. Turn off the Model 7001 and move the electrometer connections to Banks C and D.

21. Install the Model 7014 in slot 1 of the mainframe, and turn on the Model 7001.

22. Using Table 5-2 as a guide, repeat the basic procedure of steps 16 through 18 for the rest of the path pairs (test numbers 3 through 9 in the table),

23. Place the Model 617 voltage source in standby and enable zero check.

NOTE

Refer to the following procedure to check channel-to-channel isolation.

24. Turn off the Model 7001 and connect the Model 617

to the card as shown in Figure 5-6.

25. Install the Model 7014 in slot 1 of the Model 7001, and turn on the mainframe.

26. Program the Model 7001 to close Channel 1!3 (Bank A, Input 3). Make sure all other channels are

open.

27. On the Model 617, disable zero check and press

OPERATE to source 1OOV.

28. After allowing the reading on the Model 617 to set-

tle, verify that it is >lG0 (109Q).

29. Place the Model 617 voltage source in standby, and

enable zero check.

30. Using Table 5-3 as a guide, perform tests 2 through

8 for the remaining Bank A Inputs. Remember to move Bank Input connections as indicated in the table.

31. Use Table 5-3 (test numbers 9 through 35) and the

above procedure to test Banks B, C, and D.

Test equipment location

1 2

3 4 5

6 7

Bank A, Input 2 to Bank 8, Input 3

~ Bank B, Input 1 to Bank C, Input 2 Bank B and Bank C

Bank C, Input 3 to Bank D, Input 4 Bank C, Input 4 to Bank D, Input 5 Bank C, Input 5 to Bank D, Input 6 Bank C, Input 6 to Bank D, Input 7 Bank C, Input 7 to Bank D, Input 8

BankAandBankB

Bank C and Bank D Bank C and Bank D Bank C and Bank D BankCandBankD

Bank C and Bank D

Bank C, Input 8 to Bank D, Input 9 Bank C and Bank D

: 1

*Assumes Model 7014 installed in slot 1 of mainframe. Pmgrammed as slot (1) and channel.

5.10

Bank C, Input 9 to Bank D, Input 10

~ BankCandBankD

Channels closed*

1!2 and 1!13 l!ll and 1!22

1!23

and 1!34

1!24 and 1!35

1!25

and 1!36

1!26 and 1!37

1!27

and 1!38 1!28 and 1!39 1!29 and 1!40

Figure 5-6 Channel-to-channel isolation tea-t connections

Model7014

i-11

SerVice Information

Table 5-3 Channel-to-channel isolation test summary

Channel

Channel-to-channel isolation Test equipment location

1 2

3 4 5

6 Bank A, Input 7 to Bank A, Input 8 Bank A and Input 7 1!8

7 8

9 Bank B, Input 1 to Bank 8, Input 2 Bank B and Input 1 1!12

10 Bank B, Input 2 to Bank 8, Input 3 Bank B and Input 2 1!13 11 12 13 Bank 8, Input 5 to Bank B, Input 6 Bank B and Input 5 1!16 14 15 16 17

18 19 20 21 22 23

24 25 26

Bank A, Input 2 to Bank A, Input 3 Bank A and Input 2

Bank A, Input 3 to Bank A, Input 4 Bank A and Input 3 Bank A, Input 4 to Bank A, Input 5 Bank A, Input 5 to Bank A, Input 6 Bank A, Input 6 to Bank A, Input 7

Bank A, Input 8 to Bank A, Input 9 Bank A and Input 8 1!9 Bank A, Input 9 to Bank A, Input 10

Bank B, Input 3 to Bank B, Input 4 Bank B and Input 3 Bank 8, Input 4 to Bank B, Input 5 Bank B and Input 4 1!15

Bank B, Input 6 to Bank B, Input 7 Bank B and Input 6 1!17 Bank B, Input 7 to Bank B, Input 8 Bank B and Input 7 1!18 Bank B, Input 8 to Bank B, Input 9 Bank B and Input 8 1!19 Bank B, Input 9 to Bank B, Input 10

Bank C, Input 1 to Bank C, Input 2 Bank C and Input 1 Bank C, Input 2 to Bank C, Input 3 Bank C and Input 2 1!23 Bank C, Input 3 to Bank C, Input 4 Bank C, Input 4 to Bank C, Input 5 Bank C and Input 4 1!25 Bank C, Input 5 to Bank C, Input 6 Bank C and Input 5 1!26 Bank C, Input 6 to Bank C, Input 7 Bank C and Input 6 1!27 Bank C, Input 7 to Bank C, Input 8 Bank C and Input 7 1!28 Bank C, Input 8 to Bank C, Input 9 Bank C and Input 8 1!29 Bank C, Input 9 to Bank C, Input 10 Bank C and Input 9 1!30

Bank A and Input 4 1!5 Bank A and Input 5 1!6 Bank A and Input 6 1!7

Bank A and Input 9 1!10

Bank B and Input 9

Bank C and Input 3 1!24

closed*

1!3 1!4

1!14

1!20 1!22

5.12

27 28 29 30 31 32 33 34 35

*Assumes Model 7014 installed in slat 1 of mainframe. Frogrammed as slat (1) and channel,

Bank D, Input 1 to Bank D, Input 2 Bank D, Input 2 to Bank D, Input 3 Bank D, Input 3 to Bank D, Input 4 Bank D, Input 4 to Bank D, Input 5

Bank D, Input 5 to Bank D, Input 6

Bank D, Input 6 to Bank D, Input 7 Bank D, Input 7 to Bank D, Input 8 Bank D, Input 8 to Bank D, Input 9 Bank D, Input 9 to Bank D, Input 10

Bank D and Input 1 Bank D and Input 2 Bank D and Input 3

Bank D and Input 4 Bank D and Input 5 Bank D and Input 6

Bank D and Input 7 Bank D and Input 8 Bank D and Input 9

L-

1!32 1!33 1!34 1!35 1!36 1!37 1!38 1!39 1!40

Stv”iC.e lnforrnat;“”

5.3.8 Differential and common-mode isolation tests

These tests check the leakage resistance (isolation) between HI (H) and LO(L) (differential), and from HI (H)

and LO (L) to chassis (common-mode) of every bank and channel. In general, the test is performed by applying a voltage (1OOV) across the terminals and then measuring the leakage current. The isolation resistance is then calculated as R = V/I. In the following procedure, the Model 617 functions as a voltage source and an ammeter. In the V/I function, the Model 617 internally calculates the resistance from the known voltage and current levels, and displays the resistance value.

Perform the following steps to check differential and common mode isolation:

1. Turn off the Model 7001 if it is on, and remove any jumpers and test leads connected to the multiplexer card.

2. Turn on the Model 617 and allow the unit to warm up for two hours for rated accuracy

3. On the Model 617, select the 2pA range, and enable zero check and zero correct in that order. Leave zero correct enabled for the entire procedure.

WARNING

The following steps use high voltage

UOOV). Be sure to remove power from the circuit before making connection changes.

4. On the Model 617, set the voltage source for +lOOV, and select the 200nA current range. Make sure the

voltage source is still in standby.

5. Place the Model 617 in the V/I measurement func-

tion by pressing SHIFT OHMS.

6. With the Model 617 in standby, connect the elec-

trometer to Bank A of the multiplexer card, as shown in Figure 5-7.

7. Install the Model 7014 in slot 1 (CARD 1) of the

mainframe, and turn on the Model 7001.

8. Make sure all the relays are open. (Press OPEN ALL on the Model 7001.)

9. On the Model 617, disable zero check, and press OPERATE to source 1 OOV.

10. After allowing the reading on the Model 617 to settle, verify that it is >lGQ (10%). This measurement is the differential leakage resistance (isolation) of Bank A.

11. Place the Model 617 in standby and enable zero check.

Figure 5-7 Differential

Model 7014

isolation test connections

S-13

Service Information

12. Program the Model 7001 to close Channel 1!2 (Bank A, Input 2).

13. On the Model 617, disable zero check and press

OPERATE to source +lOOV.

14. After allowing the reading on the Model 617 to set-

tle, verify that it is also >lGB (1098). This measurement checks the differential isolation of Input 2.

15. Using Table 5-4 as a guide, repeat the basic proce-

dure in steps 11 through 14 to test Inputs 3 through 10 of Bank A (test numbers 3 through 10 of the ta-

ble).

16. Use Table 5-4 (test numbers 11 through 43) and the above procedure to test Banks B, C and D.

17. Place the Model 617 voltage source in standby and

enable zero check.

NOTE

Refer to Figure 5-8 for the following procedure to check common mode isolation.

18. Turn off the Model 7001, and conned the electrom-

eter to the Model 7014 as shown in Figure 5-8.

19. Repeat steps 4 through 16 to check common mode isolation. Verify that each reading is >lGQ (109Q).

Table 5-4

Differential and common-mode isolation testing

Differential or corn- : Channel man mode isolation 1 closed*

1 2 3 4 5 6 7 8 9

10 11

12 Bank 8, Input 13 14 Bank B, Input 3 15 16 Bank B, Input 5 17 Bank B, Input 6 18

19 20 21 Bank B, Input 10

22 Bank C 23 Bank C, Input 1 24 Bank C, Input 2 25 26 Bank C, Input 4 27 Bank C, Input 5 28 Bank C, Input 6 29 30 31 Bank C, Input 9

BankA Bank A, Input 2 Bank A, Input 3 Bank A, Input 4 Bank A, Input 5 Bank A, Input 6 Bank A, Input 7 Bank A, Input 8 Bank A, Input 9 Bank A, Input 10

Bank B

Bank 8, Input

Bank B, Input 4

Bank B, Input 7 Bank B, Input 8 Bank B, Input 9

Bank C, Input 3

Bank C, Input 7 Bank C, Input 8

Bank C, Input 10

NOW2

l!lO

NOIW

l!ll 1!12 1!13 1!14 1!15 1!16 1!17 1!18 1!19 1!20

NOM

1!21 1!22 1!23 1!24 1!25 1!26 1!27 1!28 1!29 1!30

1!2 1!3 1!4 1!5 1!6 1!7 1!8 I!9

5.14

33 34 35 36 37 38 39 40 41 42 43

‘Assumes Model 7’014 grammed as slot (1) and channel.

Bank D Bank D, Input 1 Bank D, Input 2 Bank D, Input 3 Bank D, Input 4 Bank D, Input 5 Bank D, Input 6

Bank D, Input 7 Bank D, Input 8 Bank D, Input 9 Bank D, Input 10

installed in slot 1 of

NOW2

1!31 1!32 1!33

1!34 1!35 1!36 1!37

mainframe. Pro-

Figure 5-8

Common-mode isolation test connections

Model7014

5.4 Calibration

There are two calibration procedures given here. The first procedure establishes the specified accuracy of the Model 7014 card with a calibrated thermistor probe monitoring the temperature under the isothermal cover. The second procedure establishes an ice-point reference for a piece of thermocouple wire from the spool intended for a Model 7014 application.

Both calibration procedures should be performed at an

ambient temperature of 23°C GK, and a relative humidity of less than 70%.

NOTE

It is recommended that the Model 7014 is calibrated in the same Model 7001 mainframe being used for norma1 applications.

5.4.1 Calibration with thermistor probe

Bench reset conditions are assumed for the Models 7001 and 2001. In general, the procedure has the following steps:

1. Set a Model 196 DMM on the 300kQ range, or a Model 2001 Multimeter on the 200kR range. (The short circuit currents are 50~A and 7@., respectively. Due to the self-heating effects of the thermistor probe at higher current, do not use a lower resistance range.) Let the Model 196 warm up for two hours; the Model 2001 for one hour.

2. Set another Model 196 on the 300mVDC range, or a Model 2001 on the 200mVDC range. Insert a 2terminal low thermal shorting bar into the voltages inputs. Zero the Model 196 after two hours (one

hour for the Model 2001) and remove the shorting

bar.

3. Set up the test equipment as shown in Figure 5-9. Remove the cover of the Model 7001 as explained in paragraph 7.5 of the Model 7001 Instruction Manual.

4. Unscrew and remove the top clamp on the connector card of the Model 7014 to allow access to trimmer RZO4. Insert the card into the Model 7001 and protect it from air drafts.

This procedure requires a calibrated thermistor probe

(Thermometrics Series CSP A207A or equivalent). The test can be automated with a bus controller.

5. Coat the probe with a thermally conductive compound and insert it into the 0.110” hole marked

“CAL” in the isothermal cover.

5-15

Take a reading of the probe resistance when it sta-

bilizes.

Using the lookup tables for the CSP A207A probe, find the Celsius temperature that corresponds to the above probe resistance. This is the temperature under the isothermal cover as measured by the probe.

8. The following equation calculates the equivalent reference junction output voltage (VRBF):

VREF = (T, + 273.15) x 0.0002

9. Close Channel 1 on the Model 7014 card and read the output voltage; it should equal the VREF just calculated. Adjust trimmer RZO4 until the equivalent

temperature equals:

(probe temp. + 0.04”C) * 0.05”C

10. Check the probe resistance again, and find the COP responding temperature with the lookup tables. If the new value differs by more than O.Ol”C from the

temperature found in step 7, repeat steps 8 and 9.

Figure 5-9

Calibrafion with thermistor probe

5.16

5.4.2 Calibration with thermocouple wire

This procedure compensates for errors of the reference

junction circuitry and establishes a compensation fat-

tor for the offset of the particular piece of thermocouple

wire. Because of an inherent error source, the thermo-

couple wire used in measuring the ice-point, absolute

calibration accuracy cannot be guaranteed.

Assuming the homogeneity of the thermocouple wire spool, errors due to thermocouple offset voltages will be significantly reduced for the entire system. For subsequent applications of this particular Model 7014 card, the same spool of wire should be used on the same channel (or one on the same terminal strip), otherwise the Model 7014 should be recalibrated.

This procedure assumes bench reset conditions on the Models 7001 and 2001.

On a Model 7014, connect the thermocouple positive lead to Channel 2 HI and the negative lead (red insulation) to Channel 2 LO. Connect copper wires to the HI and LO outputs of Bank A. Route all wires through the cable clamp and insert a small non-metallic screwdriver to adjust trimmer R204. See Figure 5-10.

Insert the Model 7014 into a Model 7001. Connect the output wires to the INPUT HI and LO terminals of the Model 2001.

Turn on both instruments and allow them to warm up for at least one hour.

Service Information

Fill a Dewar flask or Thermos half full with peasized ice made from distilled water. Fill up the

flask with distilled water. Stir the contents.

Place a twisted or welded thermocouple junction

5. into the volume of the flask occupied by ice. Cover the flask and stir contents occasionally. Allow 20 minutes for temperature stabilization. Add more ice as necessary.

On the Model 2001, select the TEMI’ function and configure it:

l Select a temperature sensor of thermocouple

and its type.

l Configure reference junction #I with the tem-

perature coefficient (+OO.ZOmV/“C) and offset voltage (+54.63mV @ 0°C) of a Model 7014.

l Select temperature units of DEG-F (to yield

better resolution than DECK).

From the CONFIC-CHAN menu of the Model 2001, select external inputs (two channels), the JNI function for Channel 1, and the TMP function for Channel 2.

From the CARD-CONFIG menu of the Model

7001,

select a delay of 1st~ for slot one. From the SCAN-CONFIG menu, select channel spacing of IMMEDIATE. Also from the Model 7001, select a scan list of l!l, 1!2.

Press STEPon the Model 7001 to start a continuous scan of Channels 1 and 2.

10.

Note the reading on the Model 2001 displays when Channel 2 is closed. If the display reads other than

32.O”F, adjust trimmer R204 on the Model 7014 card until the Model 2001 reads 32.O”F, rl count.

11.

Press OPEN ALL on the Model 7001 to stop the

scan.

5-17

Service Information

Figure 5 10 Calibration with thermocouple wire

5-18

5.5 Special handling of static-sensitive devices

CMOS and other high-impedance devices are subject to possible static discharge damage because of the

high-impedance levels involved. When handling such

devices, use the precautions listed below.

NOTE

In order to prevent damage, assume that all parts are static-sensitive.

1. Such devices should be transported and handled only in containers specially designed to prevent or dissipate static build-up. Typically, these devices will be received in anti-static containers made of plastic or foam. Keep these parts in their original containers until ready for installation or use.

2. Remove the devices from their protective containers only at a properly-grounded workstation. Also, ground yourself with an appropriate wrist strap

while working with these devices.

3. Handle the devices only by the body; do not touch the pins or terminals.

4. Any printed circuit board into which the device is to be inserted must first be grounded to the bench or table.

5. Use only anti-static type de-soldering tools and grounded-tip soldering irons.

5.6

Principles of operation

The following paragraphs discuss the basic operating principles for the Model 7014, and can be used as an aid in troubleshooting the card. The schematic drawing of the relay card is shown on drawing number 7014. 106, located at the end of Section 6.

5.6.1 Block diagram

Figure 5-11 shows a simplified block diagram of the Model 7014. Key elements include the relay drivers and relays, as well as the ROM, which contains card ID and configuration information. These various elements are discussed in the following paragraphs.

To Mainframe

Figure 5 11 Model 7014 block diagram

CLK Data Strobe Enable

User connections

5.19

Service lntormation

5.6.2 ID data circuits

Upon power-up, card identification information from each card is read by the mainframe. This ID data includes such information as card ID, hardware settling time, and relay configuration information.

ID data is contained within an on-card EEPROM 3

(UlO5). In order to read this information, the sequence described below is performed on power-up.

1. The IDDATA line (pin 6 of U105) is set from high to low while the IDCLK line (pin 5 of U105) is held

high. This action initiates a start command to the

4. Once all data is received, the mainframe sends a

ROM to transmit data serially to the mainframe

(Figure 5-12).

The mainframe sends the ROM address location to be read over the IDDATA line. The ROM then

transmits an acknowledge signal back to the mainframe, and it then transmits data at that location

back to the mainframe (Figure 5-13). The mainframe then transmits an acknowledge

signal, indicating that it requires more data. The ROM will then sequentially transmit data after each acknowledge signal it receives.

stop command, which is a low-to-high transition of the IDDATA line with the IDCLK line held high (see Figure 5-12).

Figure 5 1.7 Start and stop sequences

ID CLK

IDDATA

Data output

mm mainframe

or ROM)

Start Bit

I I

I I I I

Stop Bit

I I

1 I

(

Acknowledge

Figure .5- 13

Transmit and acknowledge sequence

5.20

5.6.3 Card relays are controlled by serial data transmitted

via the relay DATA line. A total of five bytes for each

card are shifted in serial fashion into latches located in the card relay driver ICs. The serial data is clocked in by the CLK line. As data overflows one register, it is fed out the Q’S line of the register down the chain.

Once all five bytes have shifted into the card, the STROBE line is set high to latch the relay information into the Q outputs of the relay drivers, and the appropriate relays are energized (assuming the driver outputs are enabled, as discussed below). Note that a relay driver output goes low to energize the corresponding day.

Relay control

5.6.4 Reference junction

The PRESET line on the D-type flip-flop is controlled by the 68302 microprocessor, while the CLK line of the

D-type flip-flop is controlled by a VIA port line on the 68302 processor. The Q output of the flip-flop drives each switch card relay driver IC enable pin (LJlOOU104, pin 8).

When the 68302 microprocessor is in the reset mode, the flip-flop PRESET line is held low, and Q out immediately goes high, disabling all relays (r&y driver IC enable pins are high, disabling the relays). After the reset condition elapses (-ZOOmsec), PRESET goes high while Q out stays high. When the first valid STROBE pulse occurs, a low logic level is clocked into the Dtype flip-flop, setting Q out low and enabling all relay drivers simultaneously. Note that Q out stays low, (enabling relay drivers) until the 68302 processor goes intc a reset condition.

NOTE

The circuit discussed below is located on the connector board of the Model

7014. See schematic diagram 7014-166 in Section 6.

The temperature of the reference junction on Channel 1 is measured by a semiconductor temperature trans-

ducer (U201). U201, R7.01, R203, and I7204 form the iso-

thermal measurement circuit. R204 is a calibration

adjustment potentiometer that compensates for errors

introduced by U201, R203, and R’2.01.

5.6.5 Power-on safeguard

NOTE

The power-on safeguard circuit discussed below is actually located on the digital board in the Model 7001 mainframe.

A power-on safeguard circuit, made up of U114 (a Dtype flip-flop) and associated components ensures that relays do not randomly energize on power-up and power-down. This circuit disables all relays (all relays are open) during power-up and power-down periods.

5.7 Troubleshooting

5.7.1 Troubleshooting equipment

Table 5-5 summarizes recommended equipment for troubleshooting the Model 7014.

Table 5-5

Recommended troubleshooting equipment

Manufacturer

~ Description ~Multimeter Keithley 196 or Measure DC voltages

Oscilloscope ‘TEK 2243

5.7.2 Troubleshooting access

There are four screws that attach the isothermal cover to the connector board. It is only necessary to remove these screws to gain complete access to the solder side of the connector board. Removal of the cover will damage the thermal RTV seal, which will have to be replaced (Keithley Part Number CE-16).

and model Application

2001

View logic waveforms

CAUTION

To gain access to the relay card top surface to measure voltages under actual operation conditions, perform the following steps:

live circuits. Failure to do so could result in personal injury or death.

1. Disconnect the connector card from the relay card.

2. Remove the Model 7001 cover.

3. Install the relay card in the CARD 1 slot location.

4. Turn on Model 7001 power to measure voltages (see following paragraph).

NOTE

For complete access to the component side of the relay board, it is necessary to remove the copper/vinyl shield that covers the relays (Keithley P/N 7014-308).

5.7.3 Troubleshooting procedure

Table 5-6 summarizes switch card troubleshooting.

WARNING

Lethal voltages are present within the 7001 mainframe. Some of the procedures may expose you to hazardous voltages. Observe standard safety precautions for dealing with

CAUTION

Observe the following precautions when troubleshooting or repairing the switch card:

To avoid contamination, which could

degrade card performance, always handle the card only by the handle and side edges. Do not touch edge connectors, board surfaces, or components on the card. Also, do not touch areas adjacent to electrical contacts on connectors.

Use care when removing relays from the PC board to avoid pulling traces away from the circuit board. Before attempting to remove a relay, use an appropriate de-soldering tool, such as a solder sucker, to clear each

mounting hole completely free of

solder. Each relay pin must be free to move in its mounting hole before re-

moval. Also, make certain that no burrs are present on the ends of the relay pins.

5.22

Table 5-6

Troubleshooting procedure

step Item/component

-. 1 GND pad

+6V pad +6VDC +5V pad +14.6V pad +14.6VDC

U201, pin 2 +59.23mV @ 23°C

U105, pin 5

LJ105, pin 6

WOO, pin 7

WOO, pin 2 CLK pulses

UlOO, pin 3

UIOO-U104, pins lo-18

Required condition

+5VDC

ID CLK pulses ID DATA pulses STROBE pulse

DATA pulses Low with relay energized;

high with relay de-energized.

Comments All voltages referenced to digital ground

(GND pad). Relay voltage, Logic voltage. Relay bias voltage, Reference junction sensor output. During power-up only. During power-up only. End of relay update sequence. During relay update sequence only. During relay update sequence only. Relay driver outputs.

5-23

5-24

Replaceable Parts

6.1 Introduction

This section contains replacement parts information, schematic diagrams, and component layout drawings for the Model 7014.

6.2 Parts lists

Parts lists for the various circuit boards are included in tables integrated with schematic diagrams and component layout drawings for the boards. Parts are listed alphabetically in order of circuit designation.

6.3 Ordering information

To place an order, or to obtain information concerning replacement parts, contact your Keithlay representative or the factory (see inside front cover for addresses). When ordering parts, be sure to include the following information:

1. Card model number 7014

2. Card serial number

3. Part description

4. Circuit description, if applicable

5. Keithley part number

Call the Test Instruments Repair Department at l800-552-1115 for a Return Material Authorization (RMA) number.

Complete the service form at the back of this manual and include it with the card.

Carefully pack the card in the original packing carton.

Write ATIENTION REPAIR DEPT and the RMA number on the shipping label.

Note: It is not necessary to rehxn the matrix mairframe with the card.

6.5 Component layouts and schematic diagrams

Component layout drawings and schematic diagrams are included on the following pages integrated with the parts lists:

Table 1 Parts List, Relay Card for 7014. 7011-100 Component Layout, Relay Card for 7011/

7014.

7011-106 Schematic, Relay Card for 7014.

6.4 Factory service

If the card is to be returned to Keithley Instruments for repair, perform the following:

Table 2

7014.160 Component Layout, Connector Card for

7014.166 Schematic, Connector Card for 7014.

Parts List, Connector Card for 7014.

7014.

6-l

Replaceable Pam

Table 6- 1

Parts List, Relay Card (Scanner Board) for Model 7014

Circuit Desig.

Description SHIELD

2-56X1/4 PHILLIPS PAN HD (FOR SCANNER SHIELD) SOCKET (FOR U105) SO-72 THERMAL SHIELD (FOR RELAYS) 2-56X5/8 PHILLIPS PAN HD FASTENER FA-245-1

(I’2001 TO STANDOFF AND SHIELD)

2-56X3/16 PHILLIPS PAN HEAD SCREW

(SCANNER BOARD TO SHIELD)

x00-108,118,119 CAP,.lUF,20%,5OV,CERAMIC Xl 1113,114

CAP,lUF,20%,50V, CERAMIC C-237-l CAP, lOUF, 20%, 5OV, ALUM ELEC C-489-10

:115,116,117 CAI’,l5OI’F,lO%,l0OOV,CERAMIC

1002,1003 CONN, 48-PIN, 3.ROWS

<loo-139

RELAY, ULTRA-SMALL POLARIZED TF2E-5V

‘2001 CONNECTOR, 32-PIN, 2-ROWS <106,107

RES,lOK,5%,1/4W,COMI’OSITION OR FILM

Keithley Part No.

7011.305 2-56Xll4PPH

7014-308

2-56X3 / 16PPH

C-365-.1

C-64.15OP CS-736-2 RL-149 or RL-166

(See Note 1.) cs-775-1 R-76.10K

JlOO-104 J105

IC, S-BIT SERIAL-IN LATCH DRIVER,5841A EPROM PROGRAM

ivlOO-108 JUMPER

%.~,~~

IC-536

7014.800. (See Note 2.)

J-15

6-2

Table 6-2

Parts List,

Connector Card (Terminal Board) for Model 7014

Zircuit Desig.

2201 z202

2201 .1004-1008

~1009-1011

Description

BRACKET SHIELD OVERLAY, SHIELD TOP CLAMP THERMAL RTV 4-40X3/16 PHILLIPS FLAT HEAD SCREW CABLE CLAMP 4-40X5/16 PHILLIPS FLAT HD

(SCANNER BOARD TO TERMINAL BOARD) STRIP, POLYURETHANE (FOR BOTTOM CLAMP) CONNECTOR, JUMPER (FOR CS-339-2) CONNECTOR SHIM (FOR P1002,1003) CAPTIVE SCREW (FOR TOP CLAMP)

CAP,lUF,20%,50V, CERAMIC CAP,.lUF,20%,50V,CERAMIC

SURGE ARRESTOR CG2-300L CONNECTOR, lo-PIN

CONNECTOR, 12-PIN

Keithley Part No.

BR-39 7014-302 7014-304

7011.302

CE-16 4-40X3/16I’FH 7011-304-4

4.40X5/16PFH 2001-345-l

es-476 7011-309 FA-243-1

C-237-l C-365-.1

SA-2 Tl-117.10

IT-117.12

‘1002,1003 a01

?.202 1203 1204

5201

I’

yV201-206

CONNECTOR, 48.PIN, 3 ROWS RES, 205, .l%, l/lOW, METAL FILM

RES,100,5”~,1/4W,COMPOSITION OR FILM RES,5,62K,1%,1/8W,METALFILM POT,lOK,10%,.75W,NON-WIREWOUND

IC, TEMPERATURE TRANSDUCER, AD590KH

CONN,BERG,2 PIN

CS-748.3 R-263-205

R-76-100 R-885.62K RP-89.10K

R-447 CS-339-2

6-3

WRRNING :

LLUILU

,YL Y

iis

,YY

,Y* Y

P:: =f2z-

iii3

,Y Y" Y

>e-

.y ” ”

a 2

iizl

ry y : r

iii2

.Y Y ”

.Y * Y' " <

w 2

1 +

I@-

.YX Y

kzi

Fi 2

Y Y

,Y * @

.Y Y' *

,Y Y' :

lizi

.Y Y' *

ii5ii

,Y Y’ u

I( ’

.Y * Y’ I

1 *

Lx*

,YI Y @

,Y * Y” ”

-.------I

7 m

Q 15”

0 114.6”

0 16”

Q +u

”

I @ .S”

ICI06

B I

(

+u 0

Fp2

Thermocouple Conversion Tables

A-l

Thermocouple Conversion Tables

Table A-l

N/ST Quartic Coefficients for Types S, R, B, E, J, K and J

Thermocouples’

QuarticEquatian Argument Exp. Argument Exp. Argument Exp. Argument Exp.

Types

Temperatire

Range (“a

a0 al 9 =3

-5Ot”9”0 5.5439639 +o 1.0103667 -2 -1.0944499 0 to 110” 5.8791282 +o 7.9”98118 -3 -6.74500”2

0 to 1400 6.2516859 +” 5.8347856 -3 -3.4351369 0 to 165” 6.5554932 +o 4.4519908 -3 -1.6378513 0 to 1768 6.6834421 +o 3.9334084 -3 -1.0384046

4”” to 110” -3.so51591 +2 8.7T28147 +o 6.2984807 4 9.0526670 400 to 14”” -5.2412524 +2 9.5827994 +” -1.2077351 -3 *.572x04 40” to 165” -5.0061921 +2 9.4591354 +o -9.7986687 4 2.3967559

105” to 14”” 1.4352322 +3 2.9873073 +o 6.9951678 -3 -*.8986036 105” to 1650 1.3054176 +3 3.4129348 +o 6.4741403 -3 -1.6163524 140” to 155” 1.8695088 +2 6.4091373 +o 3.4664812 -3 -2.7553724 140” to 1650 1.0863331 +3 3.9952876 +” 5.8939317 -3 -1.3595782 1400 t” 1768 -7.4180405 +‘I 2.0043202 +2 -1.8607781 -1 8.1899566 1666 to 1768 *.27oL?440 +‘I -*.353227s +2 8.0243878 -2 -1.0633404

Argument

4.9628963

2.5247577

9.40.?2202

2.4140360

3.4244511

-2.97A1601

-8.3681057

-7.8837971

6.5006637

7.Y10.3746

-2.1606150

-3.4675031

-1.3556030

-1.7212343

Reference

,unction

Correction

0t050 5.3994446 +o 1.2467754 -2 1.9934168

‘Quartic approximations t” the data as a hmction of temperature (“C) in selected temperature ranges. The expansion is of the form E = a0 + alT + a2T2 + a,? + a,‘? where E is in microvolts and T is in degrees Celsius.

-5 -“.“I t” +“.“I

Exp.

Error

Range (PV)

Exact-

*pprox.

-7 to 14

-16 to 12

-35 to 25

-55 to 35

-60 to 35

-.7 to .5

-1.6 to 1.5

-1.8 to 1.9

-.05 to .os

-.05 t” .05

-.05 to .“5

-1.Ot”1.3

-.05 to .05

Thermocouples2

Quartir Equation

’ Quartic approximations to the data as a function of voltage in selected temperature ranges (“C). The expansion is of the tom T = a0 + a,E + a,E2 + a@ + a# where E is in micmvalts and T is in degrees Cekus,

TYPO S

Temperature

Range (“C)

-5Ot”900 0 t” 1100 0 to 1400 0 to 1650 0 to 1768

400 to 110” 400 to 1400 400 to 1650

1050 to 1400 105” t” 1650 14”” to 1550 1400to1650 1400to176R 1666 to 1768

2.7849728

1.3626587

6.5660913

3.8981279

3.1267454

1.2643267

-3.922468”

-1.0845801

1.7334256

8.3038098

-6.3885209

-6.5458208

-4.3637046

-1.9681943

A-2

Error

Range (“C)

Exact-

Approx.

-11 to 3

-3 to 6

-5 to 9

-6 to 11

-6 to 12

-.05 to .“7

-.o* to .o*

-2 to 2

-.“03 t” .“03

-.“I” to ,010

-.00”5 t” .0005

-.0005 to .0005

-.I3 to .I”

-.“““5 t” .O”“S

Themlocouples3

lLpen

Temperature

Range (“C)

“0

“1 a2

=3 =4

Quartie Equation Argument Exp. Argument Exp.

-50 to 900 5.4295008 +o I.1446885 -2 0 to 1100 5.7622558 co 9.2715271 -3

0 to 1400 6.1429772 co 7.1515857 -3 0 to 1650 6.4615269 t” 5.7010917 -3 0 to 1768 6.5962120 to 5.1559203 -3

400 to 1100 -4.0674108 +2 R.7490294 +o 1.7115155 -3 400 t” 1400 -5.6047484 +2 9.6731111 +0 -2.6994046 -4 400 to 1650 -5.4505828 +2 9.5942872 +o -1.2813352 -4

1050 to 1400 1.6618159 +3 2.3048526 +0 8.7635426 -3 I”50 to 1650 1.5132838 +3 2.7958847 +” 8.1571403 -3

1400 to 1550 2.4008703 +3 4.1604579 -1 1.0549178 -2 14”” to 1650 1.5787334 +3 2.6321144 +” 8.3100314 -3 1400 to 1768 -7.1904948 +4 1.9442383 +2 -1.7913090 -1

1666 t” 1768 8.8532076 +4 -,.5014129 +2 9.5376167 ~2

Argument mp.

Argument Exp. Argument Exp.

-3.1295306 3 5.““2”496 -9

-7.1346883 -6 2.5877‘m -9

-3.7539447 -6 9.6963832 -1”

-1.8683292 ~6 2.3636365 -1”

-1.2385309 -6 l.R827613 -11

7.5039035 -7 -3.“0962RO -10

2.5536988 -6 -8.9155491 -1”

2.4468512 -6 -8.6286756 ~10

-2.3016819 -6 7.4284923 ~11

-1.9701159 -6 6.5568964 ~12

-3.0383621 -6 I.8540516 ~1”

-2.0332036 -6 1.6260416 -11

7.9264764 -5 -1.3187245 4

-1.6644901 e’ -8.3”6287” -10

P.eferencc

,“lh”ll

correction

oto50 5.2891411 +o 1.3&144x ~2

-2.0889531 -5

‘Qua& approximations to the data as a function of temperature (“C) in selcctcd tcmperaturc ranges. The expansion is of the form E = a0 + a,T + a2T2 + a3T3 + a4e whexe E

IS m mi~r”~“lts and T is in deara Celsius.

Quark Equation

Argument Exp.

Algument Exp. Aqtuuent Exp.

-50 to 900 1.6251434~ ~~-1 -2.0454379 -5 0 to 1100 1.5239494 -1 -1.3755675 -5

0 to 1400 1.4441607 -1 -9.5014952 -6 0 to 1650 1.3944190 -1 -7.4485484 -6

0 to ,768 1.3752883 -1 -6.7651171 -6

40” to 1100 4.5509556 +1 1.1284875 -1 -2.8603978 -6 400 to 1400 4.9160016 +I 1.1054589 -1 -2.3559046 -6

40” to 1650 4.8343651 +1 1.1098270 -1 -2.4353890 -6 1050 to 1400 4.1134459 +o I.2738464 -1 -4.3132296 -6 1050 ta 1650 3.7487318 +1 1.1519304 -1 -2.9827002 -6 1400to1550 8.0559850 +I 1.0442877 -1 -1.982750” -6 1400 to 1650 1.4180146 +2 9.0181346 -2 -7.4068329 -7

1400 t” 1768 3.1758093 +3 -5.8922431 -1 5.6190639 -5 1666 t” 1768 1.2883437 +4 -2.6747958 to 2.2334214 -4

Argument Exp.

2..54”4935 -9 -1.1767904 -13 I.2610922 -9 -4.42812S1 -14

6.2073358 -10 -1.5622497 -14

3.8266182 -10 -7.4517277 -15

3.1420473 -10 -5.4254872 -15

8.5173702 -11 -1.1440038 ~15

3.9276248 -,I 3.3369324 ~16

4.5164488 -11 1.8172612 -16

1.3863582 -10 -1.5283798 -1s

7.4538667 -11 ~3.7809957 -16

3.360379” -11 2.4513433 -16

-1.4487255 -II 9.4290495 -16

-2.1303241 -9 3.0369250 ~14

-8.0565860 -9 I.0882779 -13

Argument Exp.

4 Quartic approximations to Lhc data as a function of voltage in selected temperature ranges (“C). The expansion is of the ion,, T = a0 + a,E + a@’ + a,E3 + a,E4 where E is in micravolts and T is in dcgmes Celsius.

Error

Range (“Cl

Exact-

Approx.

~13,“3

4 to 7

4 to 1”

-7 tn 13 ~7 h 14

-.“‘I lo .“4

-.OR to .o!,

-.10t0.12

-.oo* t” ,002

-.“I, tn .“I,

-.“005 t” .0005

-.“005 to .“OOS ~.l, to .“8

-.“007 t” .0007

A-3

Thermocouple Conversion Tables

Quark Equation

0 to 900 0 to 1100 0 to 1400 "to1650 0 to 182"

4"" to 1100 40" to 1400

40" to 1650 105" to 1400 1050 to 1650

1400to 155" 14"" to 165"

Reference

Junction

COlTWti""

0 to 50

Exp.

Argument Exp. Aqument

-2.3614224 -1 5.7496551

-2.3893338 -1

-2.3476301 -I

-1.9185893 -I

-1.3749133 -1 5.34t6673

-3.2914888 -1 5.9766638

-9.9736579 -2 5.4976533

3.9860894 -1 4.5539656

3.3670688 +o 8.2282215

4.6252371 +o

2.2890832

2.7380621 +o

-60 1.5749253

5.7684447

5.7480761

5.5578879

-7.0976836

I.1375302

-5.6339756

-5.9963692

-5.7165679

-3.3057924

-9.1094186

-8.0141311

-3.7806912

-2.4673839 -1 5.9050303 -3 -1.226718" -6

3.6623964

2.4061224

3.2325686

2.2417410

2.4305578

Argument Exp.

-1.1808558

-10

-9.7041131 -11

-1.0838193

-2.0018428

-2.809*361

-2.7203972

-1.6156824

-10

-1"

-11

-1"

-3.6969100 -1"

-7.7901142

-1"

-9.4548852 -10

-7.8471224

-10

-8.1518033 -10

Errc”

Range @IV)

Exact-

Approx.

-.22 to .I4

-.I8 to 20

-.7to 1.0 4t05

-St"9

-."5 to ."5 4 to .5

-2.0 to 1.8

-."5 to .05

-."5 to ."5

-.05 to ."5

-."!I to ."5

-0.01 to +"."I

’ Quartic approximations to the dub as a function of temperature (“C) in selected temperature ranges. The expansion is of the farm E = a0 + a,T + a,T’ 1. a3T3 + a4e where E is in microvolts and T is in degrees Celsius.

Themoeauples6

Type B

T~~pClhl~~

Range PC,

Quark Equation Argument Exp. Argument Exp. Argument Exp.

0 t” 90” 8.9244743 -1

0 toll"" 7.2874066 -1 0 to 1400 5.7822214 -1 0 to 1650 4.992913" -1 0 to 1820 4.6255054 -1

400 to 11"" 4"" to 14""

4"" to 165" 1050 to 140" 1050 to 165" 1400t015.50 140" to 1650

1.8946288 ~i2 3.0966136 -1

2.0949015 +2 2.7222162 -I

2.2354664 +2 2.4988761 -I

3.2188156 +2 I.8282378 -1

3.4418084 +2 1.7031473 -1

3.7140306 +2 1.5828913 -1

3.9253848 +2 1.4979551 -1

Argument Exp.

-5.7447033 -4

1.8053618

-3.1771931 4 6.8254996

-1.6039309 4 2.2187592

-1.0349686 4 1.0792281

-8.2176262 -5 7.3717195

-5.8100680 -5

-3.6930932

-2.716"312 -5

-1.1561743 -5

-8.9696912

-7.0050689

-5.7276293 -6

8.2483967 -9 -4.7591774

-5 3.6830239 -9 -1.4483702

2.129966" -9 -6.4220755

6.43'20083 -10 -1.4544375

-6 4.0789445 -10 -6.6410259

-6 2.6714849 -10 -2.90*207*

1.8192801 -10 -7.8042686

Argument

-7

-1.9719121

-8 -5.1002233

-8 -1.0678514 4 -3.9111456

-9 -2.2913665

Exp.

-11 -30 to 75

-12 -35 to 9"

-12 45 to 11"

-13 6" to 12"

-13 -5" to 130

-13 -."9 to 1.0

-13 -3t03

-14 -5t05

-14 -."03 to ,003

-15 -."25t"."*"

-15 -.""I to .""I

-16 -.""I to .""I

Error

Range (“a

Exact-

Approx.

’ Quartic approximations to the data as a function of voltage in sclccted tcmpcrakm ranges (“~2).

The expansion is of the form T = a0 + aIE + a# + a,E3 + a,E4 where E is in microvolts and T is in degree8 Celsius.

A-4

Thermocouples7

Quark Equation Argument Exp. Argument Exp.

’ Quartic approximations to the data as a function of temperature (“C) in selcctcd tcmpcraturc ranges. The expansion is of the form E = a0 + a,T + a,? + a,T3 + a,+ whcrc E is in microvolts md T is in degrees Celsius

VPeE

Temperature

Range (“C,

-27” to 0

-20” to 0

-200 to 8””

-2” to -5”” 0 to 4””

0 to 1”“”

4”” to 1”“”

600 to 8”” -1.3839633

850 to 1”“” -5.150313” +4

Rdcrcnce

,lUl&O”

Correction

0 to 50

-8.5381268 +2

Argument Exp.

5.9287179

5.8754764 -+1 5.7443085 -2

5.8043714 +1 5.6118501 -2

5.8318735

5.8327591 +1 5.3761106 -2

5.8734597

6.5022632

6.7211126 +, 3.1669230 -2

-13

-1.6691278 12 4.1877018 -1

5.8637565

7.0983783 -2

+1 5.4292960 -2

+I 5.0789891 -2 +1 3.43549”” -2

+1 4.6720025 -2

Argtuncnt Exp. Argument Exp.

5.2421843

-5.9506584

-5.6288941

-5.2870656

-4.7821793

-2.9769494

-2.9237913

-3.1228607

-1.4438022

-5 3.8137875 -7

-5 ,.396”92, -7

-5 2.2327737 -8

-5 2.0825828 -8

-5 1.535284” -x

-5 1.465911” -8

-5 7.6039401 4

-5 8.1514671 -9

-4 8.5283044 4

-5

EmOr

Range OIV)

Exact-

Approx.

~5 to 5

-.5 to .4

-60 to 30 +3to4

-3 to 4

~18 to 17

~2 l” 2.5

-.“3 to .,I3

-.I,6 to .“6

Thermocouple8

Quartir Equation Argunwnt Exp. Argument

a Quartic approximations to the data as a function of voltage in selected tcmpcraturc ranges (“Cl. The expansion is of the form T = a0 + a,E + a$’ + a3E3 + apER where E is in microvolts and T k in degrees Celsius.

TYPe E

Temperatwe

Range (“c,

-270 to 0 2.8168878

-200 to 0 I.5726646

-20” to 80” M4432856

-20 to 500 1.6970287 0 to 4”” 1.7022525

0 to 1”“”

40” to 1”“”

60” to 800

85” to 1000

1.9669452

2.5192188

-7.1102114

1.6410783 +1 1.4207735 +1 1.3909529 +* 5.6554599

EXP. Argument

~~~~~~

-8.5940057

-2 -1.2102152

-2 -3.2311582

-7. -2.0830603

-2 -2.2097240

-2 -1.3560189

-2 -5.184451”

-2 47201133

-2 -9.7013068

Argument Exp.

-1.4930918 -9

-1.9577799

6.97958,” -12

4.6512717 -12

5.4809314 -12

1.8600342 -12

5.6361365

5.5638718 -13

9.3938146 -12

-10

-13

Argument Exp.

-8.7987588 -14 ~1.6696298 -14

-5.1106852 -17

-4.1805785 -17

-5.7669892 -17

-8.S537337 -18

-1.5646343 -18

-1.7775228

-3.3333675 -17 ~.““I to .““I

-1s -.“005 IO .0”“5

Elmx

Range ,“C,

Exacl-

AppPXi.

-9to6

-.3 to 3

-R to 7 ~.Itl to .I2 45 to .I4

~.9 to 1.4

-.03 to .“3

A-5

Thhermocouple Conversion Tables

Quartie Equation

Argument Exp.

-2”” to 0

-20” to 76”

-20” to 1200

-20 to 50” 0 to 4”” 0 to 760

0 to 12””

40” to 76” -5.7931005

4”” to 120” 7.1127371

60” to 76” -2.5724435

760 to 1200 3.9064962

l7c*crcncc

Junction

Comction

“to50

Argument Exp.

5.0408743 +1

4.9502533 +1

4.7062907 +1

5.0465304 +1

5.0452399 +,

5.1258213 +1

5.5861877 +1 +3 9.7718575 +1 +3 1.8969007 +1 +4 *.2157&m +2 +4 -1.4765017 +2

5.0373743 -I-l

Argument Exp.

3.2009063 -2 -6.3493968

3.2898022 -2 -6.9936031

2.5522650 -2 -2.2198295

2.8062596 -2 -6.5666305

2.8409137 -2 -6.7556436

2.0040854 -2 -4.2235982

-1.4207954 -2 3.1325181

-1.1658430 -1 1.3184454

5.3862730 -2 -2.2171472

-4.0418097 -1 4.2749984

3.6470921 -1 -2.7029005

3.0167011 -2 -7.4293513

Argument Exp.

Argument Bxp.

-5 2.5174022 -7

-5 5.11127*9 -8

-5 7 1373907 -9

-5 5.3587106 -8

-5 5.6382040 -8

-5 3.2819408 4

-5 -1.502371” -R 4 -4.8218788 -R

-5

1.8445398 -10

-4 1.6174242 -7

-4 7.211309” -8

-5

Range (PV)

Exact-

Approx.

-.2 to .3

-100 to 80

-5”” to 6””

-1.5 to 3.”

-.8 to .5

-24 to 36

-210 to MO

-2.5 to 2.8

-110 to 1””

-.I to .1

-II to 11

-.06 to +.“6

9 Quartic approximations to the data ati a function of temperature (“C) in selected temperature ranges. The expansion is of the form E = a0 + a,T + a2T2 + a# + a4p wherr E is in microvo,h and 7 is in degrees Celsius.

Then~oeou~:~

Temperature Error

Range (“C,

Quartic Equation

-200 to 0

-20” to 760

-20” to 17.00

-20 to 5”” 0 to 40” 0 to 76”

0 to 120”

40” to 76” 9.2808351

400 to 1200 -1.1075293

600 to 760 1.8020713

76” to 12”” -6.382868”

% a, =*

Aqument

Exp.

Argument

Exp.

1.8843850 -2

2.1155170 -2

2.1676850 -2

1.9745056 -2

1.9750953 -2

1.9323799 -2

1.8134974 -2

1-l 5.4463817 -3 +* 2.8651303 -2 12 4.5284199 -3 12 7.4068749 -2

Argument Exp.

Argument Exp. Argument Exp.

-1.2029733 -6 -2.5278593

-3.3513149 -7

-2.1844464 -7

-1.8094256 -7

-1.854260” -7

1.2443997

3.9094347

7.8777919

8.3683958

-1.030602” -7 3.7084018

-5.649593” -8

6.5254537 -7

-2.9758175 -7 I.0769294 -6

-1n77773 -6

-2.4644023

-1.3987013

2.5945419

-2.1962321

2.1771293

-1”

-2.5849263 -14

-11 -1.522715” -16

-12 -2.4303017 -17

-12 -1.1897222 -16

-12

-1.3280568 -16

-12 -5.1031937 -17

-12 2.114K718 -17

-11 9.936476 -17

-12 4.9012035 -18

-11 1.5521511 -16

-11 -9.9502571 -17

” Quartic approximations to the data as u function of voltage in selected temperature (“C). The cxpansian is Of the form T = a~ + alE + a,E’ i- a,E3 -F aql? where E Is in microvolts and T is in degrees Celsius.

Range ,W

Exact-

App”X

-4 to .5

-6 to 7

-14 to 1”

-.07 to .06

-.“3 to .05

-.!I to .7

-3 to 4

-.03 to .“3

-1.3 to 1.6

-.““I to ,001

-.I5 to .11

A-6

Themaca~:~’

Temperature

Range (“‘3

Quark Equation Argument Exp. Argument Exp. Argument Exp. Argument Exp. Ar@nnent Exp.

-270 to 0

-2”” to 0

-2”“to8”0

-2ota 5”” 0 to 4””

0t01370 40” to 1”“” 40” to ,370 -3.5456236

6”” to 8”” 2.1326086

85” to 1000 -9.0373549

105” to 1150 -2.5972816

R&xnce

Junction

Correction

oto50

” Quartic approximations to the data as a function of tcmpcrature (“C) in seiectcd tcmperaturc ranges.

The expansion is of the form E = a0 + a,T + a2T2 + a3T3 3. a,? where E is in microvoits and T is in degrees Celsius.

a, =I

1.3223524

-1-l 1-3 +* +3

3.957551”

3.9478446

3.6762217

4.099964”

4.0981103

3.9443859 t, 5.8953822 -3 -4.201S132

3.0191663

3.8349319

2.S608012

4.0577145 +1 9.5092149 -3 -1.0989249 S.207S276 -il -1.4576419

3.9448872 +1 2.4548362 -2 -9.0918433

+1 3.1063355 -2 +1 2.8256412 -2 4~1 +1 t, -1.599251” -4

+1 2.7508912 -2 +1 9.9993329 -3 +1 3.70917‘M -2 -3.3517324

2.4544587

-3.2619221

-2

-3

-2

-9.1607995

-1.1488433

-4.3081993

8.5714137

-1.2525700

-2.4734437

-8.7444446

9.4854151

Error

Range (PVI

Exact-

Approx.

~I.1 to 1.2 ~.OR to .05

~180 to 200

-25 1045

-25 to20

-60 to 110

-.9 to 1.4

-12to 11

-.os to ,117

-.“S to .,I3 ?“5 I” .os

46 to +,14

Temperature

Range eT,

Quark Equation

-27” to 0

-2”” to 0

-200 to 800

-20*0500 0 to 40”

oto1370

40” to 1”“”

40” to 1370

6”” to 800

850 to 1000

lOSO to 1150

I2 Qua& approximations to the data as a function of voltage in selected temperature ranges (“C). The expansion is of the form T = a0 + aIE + a@* + a# + a,ER where E k in microvolts and T is in degrees Celsius

=o a,

Argument Exp. Argument Exp.

,.i329R7S -2

2.3783697 -2

2.8346886 -2

2.4363851 -2

2.4383248 -2

2.513278S -2

-2.4707112

6.2300671

-3.9480992

-3.1617495

2.3615582

+1 2.9465633 -2 +0 2.4955374 -2 +1 3.1425797 -2 10 2.7115517 -2 +2 1.1066277 -3

=2 =3

Argument Exp.

-1.4434305 -5

-2.4382217 -6

-S.8”“85*6 -7

5.6206931 -8

9.7830251 -9

-6.0883423 -R

-3.133262” -7

-7.8788333 -8

-4.O!lOS633 -7

-2.1941995 -7

8.2516607 -7

Argument

-4.2824995

-6.8203073

2.5720615

-3.882S620

3.6276965

5.5358209

6.5075717

1.3269743

8.5482602

4.8782826

-1.3558&19

Argument Exp.

-4.2028679

-9.4854031

-3.6813679 -16

3.9120208 -17

-2.5756438 -16

9.3720918

-3.9663834 -17 I.5580541 -1s

4.5696636

-2.9316611

-13

-14

-18

-17

EmOr

Range (“C,

Exact-

Approx.

~11 lO8

4 to .5

-” to IO

~1.2 to .b

4 to .6

-2.4 to 1.2

-.“2 to .o*

-3 to .3

-.““I t<, .““I

~0012 to.““,*

-.““I to .““I

A-7

Thermocouple Conversion Tables

Error

Range (PV)

Exact-

Approx.

-9 t” 7

-.I4 t” .I3

-7 to 3.5

-2 to .9

3.8709457 +1

I3 Quark approximations to the data as a function of ternperaturr (“C)

3.7085566 -2 5.6495520 -5

m selected temperature ranges.

The expansion ifi of the form E = a0 + a,T + a2T2 + a3T3 + a,,e where E is in microvolt~ and T is in degrees Celsius

lb.1

A-8

Tektronix 7014 Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual