o

1979

MBS

NBS SPECIAL PUBLICATION 551

U.S. DEPARTMENT OF COMMERCE /National Bureau of Standards

Proceedings of the

1978 Eiectromagnetic

Interference Workshop
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards' was established by an act of Congress March 3, 1901. The

Bureau's overall goal is to strengthen and advance the Nation's science and technology and

facilitate their effective application for public benefit. To this end, the Bureau conducts

research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is performed by the National Measurement Laboratory, the National Engineering Laboratory,

and the Institute for Computer Sciences and Technology.

THE NATIONAL MEASUREMENT LABORATORY provides the national system of

physical and chemical and materials measurement; coordinates the system with measurement

systems of other nations and furnishes essential services leading to accurate and uniform

physical and chemical measurement throughout the Nation's scientific community, industry,

and commerce; conducts materials research leading to improved methods of measurement,

standards, and data on the properties of materials needed by industry, commerce, educational

institutions, and Government; provides advisory and research services to other Government

Agencies; develops, produces, and distributes Standard Reference Materials; and provides

calibration services. The Laboratory consists of the following centers:

Absolute Physical Quantities^ — Radiation Research — Thermodynamics and

Molecular Science — Analytical Chemistry — Materials Science. THE NATIONAL ENGINEERING LABORATORY provides technology and technical

services to users in the public and private sectors to address national needs and to solve national problems in the public interest; conducts research in engineering and apphed science

in support of objectives in these efforts; builds and maintains competence in the necessary

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proposes new engineering practices; and develops and improves mechanisms to transfer

results of its research to the utlimate user. The Laboratory consists of the following centers:

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Engineering and Process Technology^ — Building Technology — Fire Research —

Consumer Product Technology — Field Methods.

THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts

research and provides scientific and technical services to aid Federal Agencies in the selection, acquisition, application, and use of computer technology to improve effectiveness and

economy in Government operations in accordance with Public Law 89-306 (40 U.S.C. 759), relevant Executive Orders, and other directives; carries out this mission by managing the Federal Information Processing Standards Program, developing Federal ADP standards

guidelines, and managing Federal participation in ADP voluntary standardization activities; provides scientific and technological advisory services and assistance to Federal Agencies; and

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The Institute consists of the following divisions:

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'Headquarters and Laboratories at Gaithersburg, Maryland, unless otherwise noted; mailing address Washington, D.C. 20234. Some divisions within the center are located at Boulder, Colorado, 80303.

The National Bureau of Standards was reorganized, effective April 9, 1978.
Proceedings of the 1978

Electromagnetic Interference Workshop

Proceedings of a Workshop held November 2-3, 1978

at the National Bureau of Standards,

Gaithersburg, Maryland

Edited by:

M.G. Arthur

Electromagnetic Fields Division

National Engineering Laboratory

National Bureau of Standards

Boulder, Colorado 80303

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

Issued July 1979
Library of Congress Catalog Card Number: 79-600091

National Bureau of Standards Special Publication 551

Nat. Bur. Stand. (U.S.), Spec. Publ. 551, 57 pages (July 1979) CODEN:XNBSAV

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1979

For sale by the Superintendent of Documents, U.S. Goveinraent Printing Office Washington, D.C. 20402

Stock Number 003-003-02099-1
EDITOR'S PREFACE

The National Bureau of Standards sponsored the second Electromagnetic

Interference Workshop at its Gaithersburg, Maryland, laboratories on November

2 and 3, 1978. This proceedings is a report of that workshop.

The objective of the 1978 Workshop was to address current and future EMI

technical problems and regulatory actions, and to explore potential solutions

and what is needed for progress. To do this effectively required the meeting

together of decision-makers from both industry and government. A workshop

format was chosen as the best way to encourage dialogue among those who

produce and experience electromagnetic interference, those who attempt to

control and regulate interference through legislative and technological

means, and those who write standards of various types that impact the problem

of interference.

The workshop program was divided into two broad categories: Plenary

sessions and working-group sessions. Plenary sessions were characterized by

overview speakers selected to cover the main concerns of the workshop.

Working-group sessions were characterized by the concurrent but separate

meeting of five topical groups in a less formal setting. The five topic areas were: Communications, transportation, consumer products, industrial,

and medical.

Altogether, 206 persons registered for the workshop. A wide range of

organizations and disciplines were represented.

To what extent the workshop was successful has yet to be determined.

Certainly, the objective of providing a forum for discussion was met. Some

attendees expressed satisfaction with the endeavoidr; others expressed mixed

feelings of various kinds. In any event, herein is a record of what

transpired, as provided by the summary materials of the overview speakers and

working-group chairmen.

ACKNOWLEDGMENTS

The 1978 Electromagnetic Interference Workshop was organized at the

suggestion and with the support of Dr. John W. Lyons, Director, National

Engineering Laboratory, NBS. The workshop committee consisted of the

following persons:

C. K. S. Miller, Chairman

Wilbur J. Anson, Vice-Chairman

Dee Belsher, General Arrangements

JoAnn Lorden, Local Arrangements

Frederick P. McGehan, Publicity

Robert E. Nelson, Finances

M. Gerald Arthur, Proceedings Editor

Myron L. Crawford, Program Development

Harold E. Taggart, Program Development

Shirlee A. Brubaker, Workshop Secretary

Special acknowledgments go to the overview speakers and the session

developers who carried out the plan of the program.

Photography is provided by the editor.

DISCLAIMER

Certain papers contributed to this publication have been prepared by other

than NBS authors. The content of these papers is the responsibility of the

author and his organization.

i i i
TABLE OF CONTENTS

Page

EDITOR'S PREFACE iii

ACKNOWLEDGMENTS iii

PROGRAM V

WORKING GROUPS vii

ABSTRACT ix

CHAIRMAN'S INTRODUCTION

Charles K. S. Miller 1 THE EXTENT OF TODAY'S EMI PROBLEMS

and

PRIORITIZING EMI PROBLEMS

Chris M. Kendall 3 BIOLOGICAL ELECTRO-MAGNETIC INTERFERENCE (BEMI)

Don R. Justesen 5 FCC ACTIVITIES REGULATING ELECTROMAGNETIC INTERFERENCE

Alvin W. Paul and Jeffrey Krauss 7 EMI/EMC LEGISLATION IN THE 9 5TH AND 9 6TH CONGRESSES

Charles L. Jackson 10

VOLUNTARY STANDARDIZATION FOR ELECTROMAGNETIC COMPATIBILITY

Ralph M. Showers 12

WHAT IS NEEDED FOR PROGRESS IN EMC?

Heinz M. Schlicke 20

COMMUNICATIONS WORKING GROUP SUMMARY

John P. Murray 23

TRANSPORTATION WORKING GROUP SUMMARY

Ronald J. Wasko 27

CONSUMER PRODUCTS WORKING GROUP SUMMARY

W. Thomas Collins 29

INDUSTRIAL WORKING GROUP SUMMARY

George H. Hagn 32

MEDICAL WORKING GROUP SUMMARY

James C. Toler 38

PLENARY SESSION IV SUMMARY "THE LAST, LAST WORD"

M. Gerald Arthur 42

CHAIRMAN'S SUMMARY AND CONCLUSIONS

Charles K. S. Miller 45

iv
PROGRAM

Plenary and Working Group Sessions

Electromagnetic Interference Workshop

November 2 and 3, 1978

Thursday Morning, November 2, 1978

1. Plenary Session I Welcome

Dr. Ernest Ambler

Director, National Bureau of Standards

Washington, D.C.

Introduction

Dr. John W. Lyons

Director, National Engineering Laboratory

National Bureau of Standards

Washington, D.C.

"The Extent of Today's EMI Problems," and "Prioritizing EMI Problems"

Chris M. Kendall

Private Consultant

Running Springs, California

"Biological Electro-Magnetic Interference"

Dr. Don R. Justesen

Veterans Administration Medical Center

Kansas City, Missouri

2. Working Groups Session I What are the significant EMI problems?

How serious are they?

Which should be tackled first?

Thursday Afternoon, November 2, 1978

3. Plenary Session II

"FCC Activities Regulating EMI"

Alvin W. Paul and Jeffrey Krauss

Federal Communications Commission

Washington, D.C.

"EMI/EMC Legislation in the 95th and 96th Congresses"

Dr. Charles L. Jackson

House of Representatives Subcommittee on Communications

Washington, D.C.

"Voluntary Standardization for Electromagnetic Compatibility"

Dr. Ralph M. Showers

University of Pennsylvania

Philadelphia, Pennsylvania

4. Working Groups Session II

What solutions might be practical?

Who is responsible for solutions?

What changes in voluntary standards are needed?

What new voluntary standards are needed?

V
Friday Morning, November 3, 1978

5. Plenary Session III

"What is Needed for Progress in EMC?"

Dr. Heinz M. Schlicke

Interference Control Company

Milwaukee, Wisconsin

6. Working Groups Session III

What is the state-of-the-art of EMI measurements?

What are the limits of technology in solving EMI problems?

Where do we have enough knowledge for action?

Friday Afternoon, November 3, 1978

7. Plenary Session IV

"The Last Word"

Working Group Session Developers

"The Last, Last Word"

Workshop Attendees

vi
WORKING GROUPS

1. Communications

Organizer: John P. Murray

National Telecommunications and Information Administration

Boulder, Colorado

Panel Members:

D. D. Crombie, National Telecommunications and Information

Administration

N. N. Hankin, Environmental Protection Agency

Jeffrey Krauss, Federal Communications Commission

R. J. Matheson, National Telecommunications and Information

Administration

Jeff Young, Federal Communications Commission

J. A. Zoellner, Electromagnetic Compatibility Analysis Center

2. Transportation

Organizer: Ronald J. Wasko

Motor Vehicle Manufacturers Association

Detroit, Michigan

Invited Speakers:

Session I: Warren Kesselman, Department of the Army

Joe Kindermann, General Motors Corporation

Session II: Fred Bauer, Ford Motor Company

Myron Crawford, National Bureau of Standards

Panel Members, Session III:

Comprised of the above speakers

3. Consumer Products

Organizer: W. Thomas Collins

RCA Corporation

Indianapolis, Indiana

Panel Members:

Sessions I and III:

Harold Anderson, Litton Microwave Products

Sally Browne, Electronic Industries Association

Robert Grant, Magnavox Company

Erika Jones, Federal Communications Commission

Paul Ruggera, Bureau of Radiological Health

Art Wall, Federal Communications Commission

Session II (joint with Industrial Working Group):

Harold Anderson, Litton Microwave Products

Erika Jones, Federal Communications Commission

Paul Ruggera, Bureau of Radiological Health

Panel members from Industrial Working Group

4. Industrial

Organizer: George H. Hagn

SRI International

Arlington, Virginia

vii
Panel Members:

Session I: George Hagn, SRI International (chairman)

Frank Garlington, Sprague Electric Company

Hal Gauper, General Electric Company

Heinz Schlicke, Interference Control Company

Lou Shulman, Foxboro Company

Al Visek, Sperry Univac Company

Session II (joint with Consumer Products Working Group):

Ralph Showers, Univ. of Pennsylvania (chairman)

Tom Collins, RCA Corporation

Lou Schulman, Foxboro Company

Al Visek, Sperry Univac Company

Art Wall, Federal Communications Commission

Panel members from Consumer Products Working Group

Session III:

Mike Crawford, National Bureau of Standards (chairman)

Frank Garlington, Sprague' Electric Company

Larry Middlekamp, Federal Communications Commission

Lou Shulman, Foxboro Company

Ray Vincent, Systems Control, Inc.

Al Visek, Sperry Univac Company

5. Medical

Organizer: James C. Toler

Georgia Institute of Technology

Atlanta, Georgia

Invited Speakers:

Session I: Don Justesen, Veterans Administration

Leslie Hamilton, Health Industries Manufacturers Association

Session II:

Saul Rosenthal, New York Polytechnic Institute

Bob Flink, Medtronic, Inc.

Session III:

Bob Jenkins, Georgia Institute of Technology

Fred Cain, Georgia Institute of Technology

viii
Abstract

This report is a summary of the overview talks and session discussions at the 1978

Electrcmagnetic Interference Wbrkshop, held at the National Bureau of Standards,

Gaithersburg, Maryland, on November 2 and 3, 1978. These discussions addressed the

following questions: What are the significant Electrcmagnetic Interference (IKL) probleins?

Hdw serious are they? Which should be tackled first? What solutions are practical? Who is

responsible for solutions? What new standards or changes in present voluntary standards are needed? What is needed for progress? Irtpacted areas featured at the workshop included

CCTtnumications, transportation, consumer products, industrial, and medical. Wbrkshop

speakers and attendees represented a broad segment of decision-itiakers in both industry

and government.

Ifey vords: Electrcmagnetic bioeffects; electrcxtagnetic cotpatibility; electrotagnetic

inmunity; electrcmagnetic interference; electrcmagnetic radiation; electromagnetic

susceptibility; electronic smog; heme entertainment electronics; industrial electronics;

medical electronics; microwave electronics; non-ionizing radiation; radiation hazards;

radio regulations; radio standards; RFI; spectrum management; standardization organizations;

telecartitiunications; TJl; vehicular electronics.

ix

CHAIRMAN'S INTRODUCTION

Charles K. S. Miller

National Bureau of Standards

Boulder, Colorado

NHS organized the 1978 EMI Workshop to

provide a forum by which managers and/or

decision makers overseeing technical work

within regulatory agencies, manufacturing

industries, and users of electronics could

be exposed to factors influencing their

decision making. A large complement of the

problems related to EMI are caused by

decision makers not being aware of the

extent of the problems that are caused by

regulation, constrained by technical

limitations, or affected by user practice.

This fact was amply portrayed by several

remarks made in the 1977 EMI Workshop (to

which, unfortunately, there was no proceedings) that followed such patterns

as: "I had no idea that regulations caused

such problems," or "I had no idea there were so many new consumer products that

could be affected by electromagnetic

radiation," or "whose job is it to measure

the EM environment and publish the results

so that products can be made compatible to

local environmental conditions?"

It is the purpose of this Workshop to establish dialogue between various

groups and to surface problems that could be openly addressed. Through this

process, we hope to uncover whether the constraints to technical progress

are real or imaginary, negotiable or cast-in-concrete, economically viable or limited through legal constraints, etc. To this end we will address such

questions as: What laws are pending that will affect decisions? What are our sacred cows? Do we have too much or not enough regulation of EMI? Can

voluntary standards approaches replace regulation successfully? Do we need

to establish an organization that could coordinate EMI laws, regulations,

voluntary standards, and technical solutions? Do we have the technology (at

least the measurement technology) to solve our EMI problems?

We deliberately decided not to rely on the DoD experience in this matter

since they have a reasonably closed system in that they are their own regulator, specification writer, testing authority, and user. The civilian

sector has a much more complex task because there is less unified control in

the system. Presently, the civilian sector responds to Federal and state

laws, regulatory authorities, voluntary standards groups, unknown or poorly

defined environmental conditions, rapid changes in technology, public

pressure, marketplace competition, unexpected or unintended applications of

their products by users, and stockholders who demand a profit for their

investment. In this setting, the EMI problem is often not accorded much

attention until it becomes a pressing issue. It is now fast becoming a very

pressing issue because of the proliferation of electronic hardware in a multitude of technologies, the increasingly costly or dangerous consequences

of equipment malfunction, and the steadily increasing levels of non-ionizing

electromagnetic radiation which can and does in some cases cause malfunction.

NBS sponsored this workshop because it is a neutral government agency

and therefore has the ability to draw these various factions together. We

1
expect to learn the measurement technology deficiencies inherent in

regulation, manufacturing, and user applications. In this way, a more

effective NBS program can be planned to address the national EMI measurement

needs.

2
THE EXTENT OF TODAY'S EMI PROBLEMS

and

PRIORITIZING EMI PROBLEMS

Chris M. Kendall

Private Consultant

Running Springs, California

I am impressed and concerned with how

enormous the electromagnetic interference

(EMI) problems are at the present time, but

the problems are still in their infancy by

comparison with what they are going to be

by the late 1980 's. We are at the verge of

the electronics revolution which, according

to Business Week magazine, "... increasingly is being recognized as a force

that will have a far greater impact on society than the industrial revolution had

200 years ago."[l] If this is true, the

problems we will face in the 1980 's will be

more significant than those we now face.

Most of today's problems are solvable

through education. The main reason products are produced today with potential

compatibility problems is mainly a lack of

education and understanding of the basic

principles of crosstalk and rf transmission/reception by those who are designing many of the new microprocessor-controlled products for the consumer market and to some extent those making products for the commercial

business sector. Most companies do not want to generate emission levels that

could disrupt communication systems nor be susceptible to the same. However,

through ignorance or inexperience, products are manufactured that do result

in electromagnetic incompatibility. Fortunately, most manufacturers will

take immediate action when it is discovered their equipment is generating a compatibility problem.

Under the heading of communication problems, we find that high effective

radiating power levels do cause situations that can be classified as nuisance, as well as a potential hazard to life and property. High effective

radiated power levels have resulted in electric toasters playing music and

ungrounded steel structures causing electrical shock.

Under the heading of transportation systems are the well-known problems

associated with anti-skid brake control systems. Rf radiation from citizens

band (CB) equipment, taxi, police and fire department transmitters, and other

commercial mobile sources becomes rectified to dc or is rf coupled into the

anti-skid processor/logic circuitry causing either partial or complete brake

disruption in the vehicle. There is also concern over the expected increased

use of digital logic in the automobile for control of engine functions, and

perhaps safety devices. The engine ignition and alternator, along with

increased use of communication equipment such as CB VHF equipment and car telephones, do pose a significant interference potential if not adequately

designed.

With regard to consumer products, the increased use of microprocessorcontrolled home appliances and control systems together with home or personal

[1] Business Week, "Special Report," September 18, 1978, p. 69.

3
computers is a significant potential threat to home entertainment equipment.

Interaction of processor equipment and television/stereo systems is fully

expected. Harmonics of the clock frequency oscillator often fall precisely

on a TV receiver frequency making it impossible to protect the TV set from

the emitting source. The addition of filters on the TV set will suppress

both the intended signal as well as the unintended signal of the computer.

The industrial world, including office and business equipment, has many

areas of electrical interference concern. The broad use of distributed

processing and processor-controlled equipment makes them susceptible to power

line transients and external electric field radiation. The cable lengths

involved are long and resonant at relatively low frequencies. The cables

transmit the received power to the processor at levels above normal logic

thresholds causing disruption in the equipment they control.

In medical electronics, the radiation levels, especially in hospitals,

can be quite high, perhaps on the order of 15-20 volts per meter. Such

levels, when picked up by the remote sense leads used to monitor body

functions, can transmit this energy into wide bandwidth logic circuits,

resulting in their malfunction. If the instrument is life supporting,

personal injury could result. Better awareness of the levels expected,

together with design guidelines, is needed as a supplement to any standards

issued to insure maximum compliance.

The problems cited above all have technical solutions that would add

little or no cost to the recurring price of the products if EMI suppression

was considered in the design phase. Analysis techniques do exist that can predict both the amount of emission and the degree of susceptibility of a given product before it is committed to production. As a consultant, I have

been using such analysis techniques for many years and recently have

completed a systematic computer analysis approach called EMCad, standing for

Electromagnetic Compatibility Analysis and Design, EMCad has reduced the

cost of computer analysis for a given product to under a thousand dollars.

Whether analysis or test methods are selected, the potential electromagnetic

characteristics of a new product can be determined and solutions implemented.

As to priorities, our first concern should be with the intense radiation

problem, especially where people can be injured. Second are those areas where huge numbers of electronic devices will be used such as consumer products and transportation systems using computers and microprocessors. But

perhaps ahead of both of these comes the need for better education and

understanding of the interference problem and how to design electronic

equipment to bring the problem under control.

4
BIOLOGICAL ELECTRO-MAGNETIC INTERFERENCE (BEMI)

Don R. Justesen, Ph.D.

Veterans Administration Medical Center

Kansas City, Missouri

The controversy over biological

effects of microwaves and other rf

radiations has erupted from the laboratory

to invade the public domain and is fomented

by a curious mix of fact, speculation, and

unfounded fancy. The fact: Soviet limits

of occupational exposure to radiof requency

energy are three orders of magnitude more stringent than those recommended in the

United States. The speculation: Soviet

physicians have reported that a mild and

reversible neuropsychiatric syndrome

"neurasthenia" — occurs in workers who

labor for long periods in proximity to

power lines, to sources of rf energy, and

to generators of ionizing radiation. While

any of a host of environmental (including

physical, psychological and sociological)

factors may be responsible for the

headaches, insomnia, irritability, and

impotence that symptomatically define

neurasthenia, attempts have not been made

to determine which of these factors is

(are) responsible. Rather, the blame has been laid solely to electromagnetic

radiation. The fancy: Some contributors to the popular media, who are scientifically and technologically naive but are highly skilled in

communicating with and arousing the public, have unaccountably lowered

thresholds and have raised the ante of morbidity. In pronouncements that

leave even the most accepting Soviet pathologist perplexed and unaccepting,

these authors are claiming that cancer, heart disease, blindness, and birth

defects are the toll of electromagnetic fields at intensities that are well

below those permitted in the Soviet Union.

One result of these developments has been to sharpen the boundaries—and

the acrimony—that divide the two largest camps of radiobiological

scientists: Those who opt for a trad it ional istic , brute-force,

unless-you ' re-burning-up-you ' re-safe approach, and those who entertain the

possibility of weak-field interactions but are at a loss to specify the modi

operandi . Ignorance of mechanisms of interaction militates against

assessment of whether weak field effects are hazardous or not.

The boundaries between the scientific camps could be dissolved and their

efforts more profitably directed toward real solutions by adoption of a two-fold working hypothesis:

1. Tn simple and in complex organisms , biological receptors exist that

are sensitive to weak electric and magnet ic f ields . An abundance of data

indicates that organisms that range from single-cell to the highest evolved

are sensitive to properly modulated electric and magnetic fields. For

example, bacteria migrate and fish and birds navigate in consequence of

"signals" generated by the earth's natural fields. Other evidence indicates

that natural fields regulate the biological clocks of mammals, including

those of man. Since known (visual and acoustic) receptors are sensitive to

energy transitions on the order of photon capture and Brownian movement, the

assumption of EM receptors of rf quanta carries no burden of large-order

5
kinetic energy. The burden of Receptor Theory is the isolation and

identification of sensitive substrates both anatomically and physiologically.

2. Artif ically generated fields might constitute sources of BEMI . If

the earth's natural electromagnetic fields provide signals that not only

enable avian navigation but synchronize the mammal's biological clocks, it

stands to reason that the coupling of artificially generated fields from

power lines, and from radio and TV broadcasts, could act as a source of

biological electromagnetic interference (BEMI). Desynchronization of

biological rhythms—alteration of the electroencephalogram, upset of thermal

tides, etc. --might be the physiological correlates of the neurasthenic

syndrome.

This two-fold assumption is not a conclusion, but a speculation; it is

not a solution to a problem, only a paradigm that provides a rational means

of attacking it. By placing biological experimentation on natural and

artificial electromagnetic fields in the contexts of sensory physiology and

s ignal-and-noise analysis, a new and more successful approach to an increasingly perplexing problem may be realized.

6
ACTIVITIES REGULATING ELECTROMAGNETIC INTERFERENCE

Alvin W. Paul

Office of Chief Engineer

Federal Communications Commission

Washington, D.C.

and

Jeffrey Krauss

Office of Plans and Policy

Federal Communications Commission

Washington, D.C.

The compatibility of radio frequency

emitters and electronic devices is a matter

of prime concern to the Federal

Communications Commission. Under the

Communications Act of 1934, the FCC has

statutory authority to minimize the

electromagnetic interference caused by

emitters, but has little control over non-emitters that are susceptible to EMI.

The FCC establishes performance

standards for emitters as opposed to design

methods or standards. Hopefully, this

approach does not inhibit the diversity of

supply, technological innovation, or the

competitive structure of the electronic

industry. Part 2 of the FCC Rules (47 CFR

Part 2) defines parameters such as power,

bandwidth, spurious emissions, frequency

stability, and modulation characteristics.

The actual limits prescribed in the Rules

will vary, depending upon the specific

requirements of each type of radio service.

Part 2 of the Rules contains the

procedures for obtaining an FCC

authorization for an emitter. There are three types of authorizations: Type

approval, type acceptance, and

certification. The specific kind of

equipment determines which type of

authorization is needed. For example, type

approval is needed for microwave ovens,

marine radar and wireless microphones that

operate in the FM broadcast band. Type

acceptance is generally required for

transmitters intended for operation in any

of the licensed services. Certification is

required for field disturbance sensors,

receivers designed to operate between 30

and 890 MHz, and CB receivers that operate

at 27 MHz.

Type approval is the only form of

equipment authorization requiring

measurements performed at the FCC

laboratories at Laurel, Maryland. Type

acceptance and certification are both
bilateral procedures that require manufacturers to submit measured data to

support each application for an authorization. Our laboratory then performs

an engineering evaluation of the data to determine compliance. In addition,

we can request that the equipment be submitted to the laboratory to assure validity of the submitted data.

While the FCC has authority to establish standards for radio emitters,

it does not have comparable authority to establish standards for electronic

equipment generally. In particular, it does not have authority over electronic equipment that, through inadequate design, is susceptible to

interference from legally designed and operated emitters. It is extremely

difficult to convince a consumer that the interference he receives may be due

to his own receiver, rather than a faulty transmitter.

Although there has been legislation introduced that would give the FCC

authority to establish standards of interference immunity for electronic

equipment generally, there is some concern that mandatory government

regulation in this area might stifle technological innovation, adversely

affect equipment performance, and result in inflationary price increases.

Consequently, the FCC staff has developed a proposal for an Inquiry* into

the entire problem of electromagnetic interference to non-emitters, which

will examine alternative regulatory approaches. It is intended that this

Inquiry be a formal FCC proceeding, to gather information to support possible

regulatory or legislative initiatives in this area. The Inquiry will deal

with five main areas: Consumer education, government regulation, economics,

engineering, and manufacturing.

The area of consumer education appears to be critical. Will improved

information help consumers make better purchasing decisions? Do consumers

want a choice between more susceptible equipment and less susceptible

equipment, and are they willing to pay higher prices for less susceptible

equipment? We can speculate that manufacturers would build less susceptible

equipment if consumers demanded it, and we hope the Inquiry will supply

information either confirming or refuting this.

In the area of government regulation, we are seeking alternative

approaches to assure electromagnetic compatibility. Such approaches might

include voluntary industry sel f -regulation , mandatory government regulation,

or some combination. We are seeking information on other programs that

involve the establishment of performance standards for consumer products, to see whether those programs can be adapted to our needs. We are asking other

government agencies to submit their views on matters of interagency

coordination in areas such as research and development, and enforcement of

"truth in labeling" laws.

Economic issues deal with questions of cost, pricing and industry

structure. We are concerned not only with the cost impact of designing and

building more immune electronic equipment, but also the cost impact of

various alternative regulatory approaches. Do the administrative costs of

regulation, associated with filling out and submitting forms and similar

recordkeeping, constitute a significant burden? We are also concerned with

whether alternative regulatory programs—mandatory or voluntary—will affect

innovation, competition or diversity of supply in the electronic equipment

industry.

Engineering issues deal primarily with characterizing the environment,

developing performance standards, and developing equipment and methods to

measure compliance. While the importance of modeling the electromagnetic

environment is self-evident, it is not clear how detailed such models must be

* Editor's note: This became General Docket No. 78-369, adopted

November 14, 1978, and released November 21, 1978.

8
or what organizations should have the responsibilities to develop these

models. We are also interested in whether simple and inexpensive testing

methods can be developed to test the susceptibility or immunity of electronic

equipment.

In the area of manufacturing, we seek the estimates of equipment

manufacturers as to the impact of immunity standards upon their products.

For example, will more immune equipment perform its intended function better

or worse than susceptible equipment? What methods, if any, do equipment

manufacturers now use to reduce equipment susceptibility to interference? Is

this area considered an important selling point to consumers in terms of

advertising of immunity?

This Inquiry will ask some complex and far-reaching questions. It will

itself serve as a vehicle for a consumer education program since it will be

based on a document that will be widely distributed through public service

groups, radio clubs, and retail stores. It is only through gathering

information in this manner that the FCC can intelligently decide among the

alternative regulatory approaches that have been suggested.

9
EMI/EMC LEGISLATION IN THE 95TH AND 96TH CONGRESSES

Dr. Charles L. Jackson

House Communications Subcommittee

Washington, D.C.

EMI/EMC legislative proposals surfaced

twice during the 95th Congress. The first

proposal to rise into sight was Senate Bill

S.864 offered by Senator Goldwater. S.864

would have amended the Communications Act

to allow the FCC to regulate the

interference susceptibility of consumer electronic equipment.

Representatives Benjamin, Vanik, and

Fisher all introduced similar legislation

in the House. The Vanik and Fisher Bills

differed slightly in wording from S.864.

They would give the Commission the power to

establish minimum performance standards for

interference susceptibility. In contrast,

the Goldwater/Ben jamin language would allow

the Commission to require protective

components in consumer electronics

equipment. This slight, but important,

language difference should not obscure the

fact that these bills serve the same policy

objective—the elimination of interference

from radio transmissions, mainly CB

transmissions, to televisions, radios, and

Hi-Fi systems.

The Senate Communications Subcommittee held hearings on S.864 on June

14th of this year. The Senators heard from a wide variety of government,

industry, and citizen group representatives. Every major point of view seems

to have been represented.

Senator Goldwater 's opening statement explained both the technical and

policy problems created by EMI and susceptibility legislation. In a personal

aside, the Senator noted that as a radio amateur, he had been aware of this

problem for a long time, and that the problem had gotten worse since the

introduction of tubes, transistors, and integrated circuitsi His statement

made it clear that he wanted to see the EMI/EMC problem resolved, preferably

without recourse to federal regulation, and that he hoped that the hearings

would get manufacturers on the road to providing improved equipment.

The lead-off witness was FCC Chairman Charles Ferris who explained the

FCC's views on both the legislation and on the susceptibility problem more

generally. He pointed out that there are both technical and economic

problems involved. He also touched on a number of other issues: Standards,

characterization of the EMI environment, the impact of improved consumer

awareness, and the possibility of recent changes in the susceptibility of

newly designed consumer products.

Chairman Ferris concluded with the statement, "Whether or not the

Congress decides to confer this authority at this time, the Commission will

independently pursue, under its existing authority, the significant problem

to which S.864 is addressed."

One week before the Senate hearing. Chairman Lionel Van Deerlin and

ranking minority member Lou Frey of the House Communications Subcommittee

10
introduced a bill, HR13015, the "rewrite" of the Communications Act of 1934.

This major legislative proposal dealt with EMI and susceptibility issues with

four non-traditional proposals.

Section 412(9) would require the regulatory commission to prescribe

rules governing the interference potential of equipment. This language does

not restrict the commission to regulating only the external effects of

equipment. Thus, in essence, it is very similar to the proposals by Senator

Goldwater, et al.

Section 412(10) would allow the regulatory commission to regulate the

performance characteristics of television receivers. This language would

subsume the 1962 All Channel Receiver Act and would eliminate the possibility

of any law suits challenging the commission's authority to regulate TV

receivers. It also includes, redundantly in light of 412(9), authority to

regulate the susceptibility of TV receivers to EMI.

Section 707(b)(1) requires the director of the National

Telecommunications Administration (NTA) to conduct a study to characterize

the electromagnetic environment in the United States. And Section 707(c)(1)

requires the director of the NTA to conduct a two-year study of problems and

issues relating to the susceptibility of consumer electronics to EMI.

HR13015 would authorize ten million dollars to be expended for those studies.

Thirty-three days of hearings were held this last summer and fall on HR13015. Four hundred and eighty-four witnesses appeared. However,

relatively few of the witnesses commented on the EMI/susceptibility language.

Predictably, television set makers opposed section 412(10). Radio amateurs

supported the language of 412(9) and 412(10). The Motor Vehicle

Manufacturers Association was, to the best of my recollection, the only group

to comment on and support the EMI environment survey.

Current plans call for a "rewrite of the rewrite" to be prepared for

introduction in late January or early February of 1979. So far, the EMI

provisions of the rewrite seem to have stood up relatively well. I would be

surprised if there were major changes in this area. However, the process is

still open for suggestions, comments, and further input. Nothing is cast in

stone. Your thoughts would be welcomel

11
VOLUNTARY STANDARDIZATION FOR ELECTROMAGNETIC COMPATIBILITY

Dr. Ralph M. Showers

University of Pennsylvania

Philadelphia, Pennsylvania

1. INTRODUCTION

The voluntary standardization effort

in the electromagnetic compatibility field

is extensive. The purpose of this

presentation is to describe the scope of

the effort, indicate what it has

accomplished, and provide suggestions as to

where it may lead in the immediate future.

Because of the limited nature of this

discussion, it is not possible to give

complete details on the program. The

details will be furnished to interested

persons by the author upon request.

2. AMERICAN NATIONAL STANDARDS INSTITUTE

In many respects, the American National

Standards Committee C63, Radio-Electrical

Coordination, acts as a central

coordinating body for the voluntary

standardization effort in electromagnetic

compatibility. The following are three of

the purposes of the Institute as quoted

from its Constitution:

"(1) To serve as the national coordinating institution for voluntary

standardization and certification activities in the United States of America

through which organizations concerned with such activities may cooperate in

establishing, improving and recognizing standards, based on a consensus of

parties-at-interest, and certification programs to the end that such

activities remain dynamically responsive to national needs; that duplication

of work is avoided; and that individual enterprise and initiative are encouraged

.

(2) To represent the interests of the United States of America in

international nontreaty standardization and certification organizations with

which it is or may become affiliated.

(3) To serve as a clearinghouse for information on standards and

standardization and certification work in the United States of America and

abroad .

It carries out these purposes primarily through the authorization of

"American National Standards." With regard to this approval procedure, it

should be noted that, "The approval of a standard by the Institute implies a consensus of those substantially concerned with its scope and provisions. In

standardization practice a consensus is achieved when substantial agreement

is reached by concerned interests according to the judgment of a duly

appointed authority. Consensus implies much more than the concept of a simple majority, but not necessarily unanimity." The organization of the

Institute includes a number of councils representing, for example,

organizational members, company members, consumers, various standards boards

and committees, and the International Standards Council which oversees the

operation of the United States National Committees for the International

Standards Organization and the International Electrotechnical Commission.

12
3. SECTIONAL COMMITTEE C6 3

The scope of C63 is as follows:

"Development of definitions and methods of measurement of noise and

signal strengths, determination of levels of signal strength, levels of

interfering sources, limiting ratio of noise to signal and development of

methods of control of influence, coupling, and suscept iveness .

As can be seen, this scope is quite broad and generally covers all

aspects of EMC. Participation in the activities of C63 is generally by

member organizations who designate delegates. The current list of member

organizations is shown in Fig. 1. It should be noted that except for a limited number of members-at-large , individuals are not members of this

committee. The administrative work of the committee is carried out by the

sponsor, who presently is the Institute of Electrical and Electronic

Engineers, Inc.

4. INTERNATIONAL VOLUNTARY STANDARDIZATION

Work is carried out both in the International Organization for

Standardization (ISO) and the International Electrotechnical Commission

(lEC). The major committee concerned with this activity is the International

Special Committee on Radio Interference (CISPR) which is affiliated with the

lEC and which has six subcommittees covering the following areas:

Instrumentation and Measurements; Industrial, Scientific and Medical

Equipment; High Voltage Lines and Equipment; Ignition; Receivers; and

Appliances. It has issued many reports, recommendations, and specifications

in the field and its recommendations and specifications are being adopted by

many countries as part of their national regulations. Other committees of

lEC concerned with electromagnetic compatibility problems include TC 9,

Electric Traction Equipment; TC 12, Radio-Communications; SC 17D, Low-Voltage

Switchgear and Controlgear; TC 18, Electrical Installations in Ships; TC 22,

Power Electronics; TC 34, Electric Lighting; TC 44, Electrical Equipment of

Industrial Machines; TC 57, Power Line Carrier Systems; TC 64, Electrical

Installations of Buildings; TC 65, Industrial Process Measurement and

Control; TC 75, Environmental Conditions; and TC 77, Electromagnetic

Compatibility between Electrical Equipment Including Networks. In addition,

in ISO, TC 20 is concerned with EMC aspects of aircraft and space vehicles,

and TC 97 with EMC aspects of computers and information processing. Also,

there are other international committees concerned with EMC matters. As an indication of the extent of the interest in EMC standards in the lEC, a survey of the 180-odd technical committees and subcommittees of lEC was recently made. More than 50 of these technical committees and subcommittees

indicated a direct interest in EMC.

5. THE VOLUNTARY STANDARDIZATION EFFORT

In carrying out its responsibility, American National Standards

Committee C63 has made a survey of its activities, not only nationally but on

a worldwide basis in the EMC field. Of the 11 pages of items which are either specific standards or work related to the development of specific

standards, nine of these pages are concerned with voluntary standards

activities. Approximately two pages are concerned with military or government standardization activities. ANSI itself has a number of projects

underway. The three most important are:

C63.2 - Specifications for Radio-Noise and Field-Strength Meters, 0.015 to

30 Megahertz.

C63.4 - Methods of Measurement of Radio-Noise Voltage and Radio-Noise Field

Strength, 0.015-25 MHz.

13
C63.12 - Recommended Practice in System Electromagnetic Compatibility:

Part 1 - Rationale for Developing Limits.

A revision of the first of these has recently been accepted as an approved national standard and is presently being printed. The second is out

for ballot as an approved revision of a current national standard. The third

is a new document, which has been approved for trial use for a period of one

year. It is currently in the galley-proof stage.

In order to place these documents and other documents which have been

developed in the voluntary standards effort in some sort of perspective.

Table I has been prepared. The first item in the table is definitions, and

indicates several of the more important publications. The remainder of the

table identifies for each EMC phenomenon, for example, emission or susceptibility of a specific source, related standards or standardization

efforts that can be identified as being concerned with instrumentation,

techniques, or limits. Table II shows those standards pertaining to EMC

control techniques.

6. PRESENT PROGRAM

Figure 2 shows a concept of a program for bringing many of these

standardization efforts together. It is clear that the several documents

containing definitions should be examined for consistency with the objective

of trying to produce a single vocabulary. Many of the terms presently

being used are common in several vocabularies but a significant number are

not. Presumably, these differences can be reduced, but probably not

eliminated because of the different purposes for which each vocabulary

serves

There is no real reason why we should not have a common instrumentation

standard. Recently, ANSI has taken a major step in this direction in

adopting standards that are not ony consistent with practice in the United

States but also that are followed in the CISPR. In this concept, one has a choice of instrumentation depending upon his immediate needs, but when he

makes the choice he uses an instrument of agreed upon specifications.

In the techniques area, the concept is that many of the devices can be

measured using a standard technique; however, it will be necessary to

recognize certain variations of the standard technique in order to accomodate

special types of equipment. Hopefully, variations will not be so extensive

as to invalidate the concept. Certainly, in developing this concept, one of

the fundamental rules of the game should be to bring civilian and military

practices together. Many have suggested a civilian MIL-STD-461 . Hopefully,

we can do better than that and actually have an American national standard

that is acceptable, in so far as techniques are concerned, to both military

and civilian sectors. In developing such a standard, one of the objectives

would be to try to improve the realism of test procedures with regard to

their ability to measure basic parameters; that is, parameters which are significant for the application of limit criteria in so far as conduction,

induction, and radiation phenomena are concerned.

With regard to the area of limits and limit guidelines, we hope that in

the very immediate future many users of EMC standards will make a careful

review of document C63.12. This document is admittedly not as comprehensive

as we hope it will be finally, since at the moment it deals only with

narrow-band emission and susceptibility. However, the criteria which are discussed in the document seem to be very basic, and if the principles used

there can be accepted, one can then proceed to expand the scope and

usefulness of this document. In the establishment of limits (and their

associated measurement techniques) participants in the standardization effort

will have to take into account such factors as cost of suppression and

shielding, the cost of efficient circuit design, the value of hazards removal

14
(hazards being defined as having to do with health, safety, and comfort), and

the establishment of valid statistical parameters which are significant in

the computation of probability of interference.

If the basic documents can be prepared, then work can go forward with

specialized documents to the extent that they are needed, but which will

hopefully be quite consistent with the basic documents.

7. CONCLUSIONS

In considering these matters, it is important to recognize that many

significant changes in technology are taking place on a regular basis. Such

changes include the following: Increasing use of digital techniques for

replacing analog techniques, optical techniques, electronic power conversion,

satellite communications, new medical devices, and ground transportation

systems

.

Clearly, it is not anticipated that EMC problem^ will disappear. There

will always be a conflict between undesired emission levels and sensitivities

of systems to desired emissions. In order to promote the electromagnetic

compatibility of these systems as they develop in the most efficient manner,

we must have standards which are relatable to basic electromagnetic emission,

coupling, and susceptibility phenomena, and an approved body of technological

know-how which will enable efficient application of the available techniques.

Finally, the contributions of the voluntary standards effort should be

recognized. It is obvious that the development of a more uniform set of

standards than currently exists is a desirable objective and will be

achieved. Steps currently being taken should accelerate the process.

15
Figure 1 ORGANIZATIONS REPRESENTED BY DELEGATES TO C63

Aeronautical Radio, Inc. American Radio Relay League

Association of Home Appliance Mfgrs.

Association of American Railroads

Canadian Standards Association

Computer Business Equipment

Manufacturers Association

Department of Agriculture, Rural

Electrification Administration

Department of the Army, Development

and Readiness Command

Department of Commerce, National

Bureau of Standards

Department of Commerce, National

Telecommunications and

Information Administration

Department of Energy, Bonneville

Power Administration

Department of the Interior,

Bureau of Reclamation

Department of the Navy

Naval Electronic Systems Command

Department of the Navy

Naval Sea Systems Command

Department of State

Electric Light and Power Group

Electrical Testing Labs., Inc. Electronic Industries Association

Federal Aviation Administration

Federal Communications Commission

IIT Research Institute

Institute of Electrical and

Electronic Engineers, Inc.

Motor Vehicle Manufacturers Association

National Association of Broadcasters

National Electrical Manufacturers

Associat ion

Society of Automotive Engineers, Inc. Society of the Plastics Industry

Telephone Group

Western Union Telegraph Company

Figure 2

EMC PRACTICES AND STANDARDS

1. The Electromagnetic Environment

Description - characterization and levels

Natural and man-made

2. Instrumentation

3. Techniques and Limits

3.1 Emitters

Transmitters (including handi talkies)

ISM

Ignition

High voltage lines

Appliances - fluorescent lights

Systems

3.2 Susceptors

Receivers

Audio systems

ISM

Telecommunications

Appl iances

Systems

4.0 Hazards

5.0 Methods of control

Filtering, shielding, bonding, calibration

16
Table I - Relationship Between Various EMC Standards Activities

Definitions

IEEE 100

MIL-STD-461

lEV Publication 50 (902) (CISPR)

(TC 77, WG 1)

EMISSION INSTRUMENTATION TECHNIQUES LIMITS

EM Environment

( natural and

man-made

)

ANS C6 3.12

CCIR

ANS C6 3.12

EIA (Site

Survey

)

IEEE, CISPR,

CCIR

ANS C63.12

EIA (Designers'

(Guide

)

CCIR

Transmitters

( incl . radar

)

SAE AIR 1225,

1255

lEC 244

FCC Parts 2,15

ITU

MIL-STD-462 , 449

469

IEEE 284

FCC Part 15

(Doclcet 19356 ) ITU

MIL-STD-461

OTP (radar)

Industrial

,

Sc lent if ic

,

Med ical

CISPR Pub. 16 ANS C6 3.2

lEC 65 (ionizing

rad iat ion

)

SAE AIR 1225,

1255

IEEE 54,139,140

FCC Part 18

CISPR Pub. 11 MIL-STD-462

ANS C63.4

ANS C63.12

MIL-STD-461

CBEMA (EDP/OM)

FCC Part 18

lEC Pub. 9 CISPR Pub. 11

Receivers

(inc. CATV)

ANS C6 3.2

CISPR Pub. 16 SAE AIR 1225,

1255

CISPR Pub. 13 lEC 106,107

IEEE 187,214,

213,263

EIA RS 378

FCC Part 15

MIL-STD 462

ANS C6 3.12

CISPR Pub. 13 FCC Part 15

lEC Pub. 9

Ignition CISPR Pub. 16 ANS C6 3.2CISPR Pub. 12 SAE J551

MIL-STD-462

EIA TR 8.12

CISPR Pub. 12 SAE J551

lEC Pub. 9 MIL-STD-461

High Voltage

Lines and

Equ ipment

CISPR Pub. 16 CISPR Pub. ( ) IEEE 430

NEMA 107 and

Bushing Tap

Msmts

.

CISPR Pub. ( ) lEC Pub. 9

Appl iances CISPR Pub. 16 ANS C6 3.2CISPR Pub. 14,15

ANS C63.4

FCC OCE 20 (microwave

ovens

)

Part 15 (Garage

door opener)

NEMA WD2

MIL-STD-462

CISPR Pub. 14, 1^ lEC Pub. 9 FCC Part 15 NEMA WD 2 NIL-STD-461

MIL-STD-1337

Power Equipment lEC: (TC 77

)

34-1 (Turb.

gen. harm)

(TC 17, Switchgear ) (TC 22, Power

suppl ies

)

IEEE 469 (Transf.

Noise

)

MIL-STD-745

17
Table I (cont.)

EMISSION INSTRUMENTATION TECHNIQUES LIMITS

Systems CISPR Pub. 16 lEC 533(SHIPS)

MIL-E-6051

RTCA DO 160

SAE ARP 937

( jet eng ine

)

SAE ARP 1147

(aircraft

)

STANAG 3516

lEC 533(SHIPS)

MIL-STD-704

MIL-STD-442

( telemetry)

MIL-S-13715

trans ients ( veh

MIL-E-6051

RTCA DO 160

STANAG 34 56,

3614

SAE AIR 1261

SUSCEPTORS

Rece i vers CISPR Pub. 13 lEC 315-3,5,8

IEEE 184,185,

294

EIA TR 8 SAE AIR 1209

MIL-STD-462,

449

MIL-STD-461

Audio Systems CISPR SC E MIL-STD-462

SAE AIR 1209

CISPR SC E MIL-STD-461

Industrial

,

Scientific,

Med ical

TC 65(Ind. Cont)

MIL-STD-462

SAE AIR 1499

1209

NEMA (Pacenaker)

SAMA

AAMI (Pacemaker)

MIL-STD-461

SAE AIR 1499

SAMA

Telecommunicat ion s CCIR

IEEE 455 (L.B.

)

367 (Gnd PR)

368 (Induced

Noise

)

SAE AIR 1207

MIL-STD-462

CCIR

EIA TR 41

Appliances SAE AIR 1207

MIL-STD-462

, .

SYSTEMS MIL-STD-442

( telemetry)

SAE (gnd trans)

lEC TC17 (swgrsurges

)

lEC 533 (SHIPS) lEC 533 (SHIPS)

18
Table II - Standards Pertaining to EMC Control Techniques

CONTROL METHODS INSTRUMENTATION TECHNIQUES LIMITS

Shield ing lEC 169-1

TC 46 (connectors)

MIL-STD-285

IEEE 299

SAE ARP-1173

{ gaskets

lEC 169

Filters lEC 161

MIL-STD-220

SAE ARP 936 (cap)

SAE AIR 1172{filter s)

Bond ing

Ground ing

MIL-STD-5087

MIL-STD-1310

Antenna Calibr. SAE ARP 958

Impulse Strength

and Bandwidth

SAE AIR 1267

IEEE 376

Hazards C95 (proposed)

IEEE (GIM)

lEC TC 61, 74

MIL-STD-1512

MIL-STD-1377

lEC TC 61, 74

ANS C9 5.1

ANS-C105 (Blast)

MIL-P-24014

19
WHAT IS NEEDED FOR PROGRESS IN EMC?

Dr. Heinz M. Schlicke

Interference Control Company

Milwaukee, Wisconsin

1. THE PROBLEMS AND THEIR BASIC CAUSES

There is a growing need for

electromagnetic compatibility (EMC). But,

simultaneously, there is widespread

dissatisfaction with conventional

approaches to achieving EMC. It is hard to

apply to the burgeoning, modern,

microprocessor- computer- controlled

(non-communications) systems as, e.g.,

industrial and process control,

transportation, health care, etc. By

extracting the real reasons for such

justifiable complaints about established

EMC, we can develop clear guidelines for a new EMC permitting very satisfactory,

cost-effective solutions for civilian

electromagnetic interference (EMI). To

distinguish this new approach patently from

the conventional (military-oriented)

electromagnet ic compatibility , we shall

call it ELECTRO-MAGNETIC COMPOSSIBILITY , the much-needed new, adaptive technique.

It is principle- (not spec-) oriented,

results and cost- (not documentation-) directed, and stresses systematic

co-planning of EMC. But let us first marshal the key complaints and the real reasons behind them.

a) Complaint: " EMC often does not work ." Reason: Conventional EMC was developed essentially for communication systems. There we have

narrow-band senders, defined channels, and tuned receivers. In

contrast, in control systems we have broadband sources of noise

(transients) and field concentrations; untransparent , "spread"

transfers; exposed receptors, some often quite unsuspected. Hence,

in view of the bas ically different operating cond itions , we cannot

apply many of the methods, essentially developed for communications

systems, to control systems.

b) Complaint: "Often eliminating one problem creates another problem .

Reasons: Three major reasons are involved: (i) The nonl inear ity

inherent in feedback systems; (ii) many a misconception and the many

antinomies imparted by mandatory safety measures and by spread (in

space and frequency); (iii) see c) below. Things cannot be taken out

of context with impunity.

c) Complaint: " EMC is unscientific , unpredictable , and often

' brute-force ' . " Reason: Because of the indeterminacy of boundary

and operation conditions, standards are often grossly oversimplified . This results in worthless convenience. One must use realistic models

and simplifications. Theory can be a very practical thing (as will

be shown)

d) Complaint: "I^ would 1 ike to have s imple step-by- step rules .

Reason: EMC is not for cookbook engineers. Such unimaginative,

rigid people are costly. Cost- effective EMC is not a routine

affair. You must use the code and your headl

20
e) Complaint: " EMC is costly . " Reason: Only if approached

incorrectly. But what is the correct approach?

2. THE SOLUTION: ELECTRO-MAGNETIC COMPOSSIBILITY

First, we must accept the impact of a) mandatory safety codes ( safety

first I

)

, consequential for both normal and abnormal operating conditions,

including the 'oozing' of 60 Hz throughout the whole system; b) the spatial

spread of large, fast systems (quasi-static considerations are inadequate);

and c) the unavoidabil ity of exposed receptors which must operate in very

noisy places to do their job. We cannot permit presumptive simplifications

pretending that such conditions do not exist.

Next, system planning and EMC planning must go hand in hand. EMC

planning requires continual feed-back and feed-forward between analysis and

control. Hereby we must allow the right hemisphere of the brain (holistic

thinking) to participate in the optimization process which is both generic

and specific.

For cost-effective decritical izat ion of the system, we must plan along

three generic lines:

a) Partition of the system into (i) quiet spaces containing the low

amplitude fast logic; (ii) semi-quiet spaces , interfaces, containing

high amplitude, slow I/O devices; and (iii) noisy spaces where the sensors and actuators are exposed to noise.

b) Isolation, (i) Shielding and filtering quiet and semi-quiet spaces;

(ii) isolation of control elements by electro-optic isolators; and

(iii) isolation of exposed receptors by use of non-contacting

sensors, isolation amplifiers (all three ports), and/or fiberoptics .

c) Redundancy of data handling systems. Large scale integration makes

affordable duplication or triplication of whole critical sub-systems,

going beyond error-correcting coding. For power handling systems,

redundancy is replaced by subdividing in power aggregates.

This generic approach is very much facilitated by solid state

developments still very much in flux:

* Electro-opt ics (limited linearity; use V/F conversion if needed).

* Microprocessors , partly replacing hardware by software.

* CCD '

, permitting great reduction in hardware; most important:

non-contracting, self-scanning, fast image sensors.

* Solar cells for complete isolation of power in hazardous areas. Specific remedies can be classified as null if ication (localized

suppression or cancellation) and differentiation . Differentiation of noise

and signal can be direct or indirect . Direct differentiation means staying

with the same FATTMESS criterion (Frequency, Amplitude, Time, Temperature,

Mode, Energy, Size or structure. Statistics). For instance, staying with F: Use a filter to separate low frequency signal from high frequency noise.

Indirect differentiation is more sophisticated filtering, using several other

FATTMESS criteria to handle one criterion that is difficult or costly to

control directly. Typical are slew rate limiting, averaging, etc.

Finally, we must finish off some sick sacred cows. Some of the most

blatant cases of misleading simplifications happen with the supposedly most

simple EMC measures—grounding, shielding, and filtering. Unfortunately,

such unrealistic simplifications seem to be sanctioned by long usage. They

are nevertheless wrong and cause much frustration. These misconceptions and

their corrections are as follows:

21
a) The concept of " control common " is a wishful myth for large, fast

systems. Calling something a ground does not make it so. But

electro-optic isolators eliminate much of the grounding problems.

b) The unrealistic plane- wave concept of shielding is replaced by

equivalent spheres, cylinders, and/or pairs of finite-distance

planes. Size is also important for low frequency magnetic shielding

and saturation effects.

c) Probably the most flagrant case of EMC error is the insertion loss

measurement of powerfeed line filters in 50/50 ohm interfaces (or

other totally uncritical methods ) . This does not guarantee that the

filter will work in real interfaces which are mostly variant and

indeterminate. Filter dysfunction, in the form of ringing, insertion

gain, and/or poor stopband performance, is often quite consequential

and not improved by brute-force overdesign. If the filters are made

multi-section and lossy in the pass-and transition band, they will

meet the coming lEC (CISPR) worst-case standards. Two alternate test

methods are involved; the simplest is replacing the 50/50 ohm by

0.1/100 and 100/0.1 ohm. The method is based on a broad data base of

60 Hz interface impedances as boundary conditions for a new matrix

theory of severely mismatched filters. The modified method has only

to be applied for 2 kHz to 200 kHz. If the filter works in this

range, the 50/50 ohm method is acceptable for higher frequencies.

Naturally, the information presented here can be only cursory. The IEEE

Educational Activities Board is presently offering a Continued Education

Course on ELECTRO-MAGNETIC COMPOSSIBILITY, by the author. For more details

on this call H. Schlicke at 414-352-7085 (for obtaining the text) or

V. Giardina (IEEE Service Center) at 201-981-0060 (for arranging the course).

22
COMMUNICATIONS WORKING GROUP SUMMARY

John P. Murray

National Telecommunications and Information Administration

Boulder, Colorado

1. INTRODUCTION

Although the communications working

group sessions generally followed the

topics suggested for the workshop as a whole, a number of special interests

consumed most of our time and not all of

the topics were raised. The group was too

small to represent a cross-section of all

the affected community, although issues

raised were of a character that appeared

broadly applicable.

In the communications context, we suffer from definitional problems with the

term "Electromagnetic Interference." For

communications planning and engineering,

EMI is a general term that encompasses the

effects of very low-level signals, as well

as the higher levels which were also of concern to the workshop. To many people,

including the majority of those attending

the working group sessions, EMI means high-level signal influences on non-communications equipment and biological

systems

.

In my judgment, the high-level situation should be treated as a logical

subset of the more general problem. By so doing, we can expect to realize

symbiotic benefits in the various special interest subjects. As a minimum,

dialog between interested parties is less ambiguous and the chances for

complementary work are much improved.

But the high-signal-level distinction continues. In this report, I have

tried to reflect the views of the working group rather than my own prejudices. Accordingly, emphasis is on interference effects to

non-communications equipment and, to a limited degree, on living systems.

2. PROBLEMS

Problems of concern to this group included:

a) The lack of a single source of administrative authority;

b) the lack of a source of environmental definition;

c) adverse effects on industry or mandatory controls and regulations;

d) the lack of awareness of EMI effects on the part of many people who

are being affected;

e) interference from systems not intended to radiate (such as arc-welders)

.

A strong consensus developed around the argument that trends in the

evolution of the U.S. economy are spectrum intensive and that EMI problems

will continue to grow both in number and complexity.

23
3. SOLUTIONS

In general, the group felt that the principal barriers to solutions of a broad range of problems were economic or institutional rather than

technolog ical

.

Several approaches to improving the present EMI situation were discussed, but it seemed clear that no participant felt that there was a well-defined solution. Three approaches are the following:

a) Education. Improve understanding of the EMI problem among designers,

manufacturers, regulators, and users.

b) Provide a better definition of the EM environment.

c) Develop a more comprehensive framework for the assessment of EMI to

avoid the penalties of suboptimization when specifications are drawn

for individual units and components.

4. PROBLEM/SOLUTION DISCUSSIONS

Several participants expressed a strong need for a comprehensive

definition of the electromagnetic environment for very general situations.

The environment to be experienced by automotive electronics was the example

receiving the most attention. While environmental data has significance in a broad range of applications, discussions in this working group concentrated

on the problems of compatible designs for electronic and communications

equipment. As with other topics, the term "environment" was not clearly

defined. While many users would prefer a comprehensive definition of signals

to be encountered in various locations, a list of signal sources and selected

characteristics would be a big help. At the moment, very little data of this

kind are available to the community at large.

Designing to worst case possibilities was raised as an alternative to

environmental definitions. Some concern was expressed that such an approach

imposes undue constraints on the design, cost, or use of susceptible systems.

There was a strong consensus regarding the need for a program with more

focus and cohesion. The topic was discussed without a full understanding of

what the "program" is now or should be. In general, elements of the program

were thought to include research, standards, instrumentation and measurement

procedures, measurements, definition of cause and effect relationships,

environment definition, and related legislative and regulatory activity.

While a strong role for industry was acknowledged, the principal concern expressed was directed to the many government participants at Federal, State,

and local levels.

Concern was expressed about the stultifying effects of premature

regulation, although a need for guidelines and voluntary standards,

education, and basic information (generally to be supplied or encouraged by

government) was widely acknowledged.

Meaningful measurements are important to the solution of the EMI

problem. However, lack of a definitive statement of the overall problem

precluded a very clear response. There was general accord that measurements,

measurement procedures and related standards, and instrumentation were necessary to define

a) susceptibility (of electrical, electronic, and communications

devices)

,

b) emissions, and

c) the electromagnetic environment.

24
In addition, the enforcement function produces similar requirements.

Some key points follow:

a) The scope of the problem is extremely large—too large to permit

exhaustive measurements of all items of interest. More appropriate

is a rational combination of analysis and measurement.

b) Measurement objectives should include the definition of statistical

distributions. This is particularly true where factors have large

variations, as is the case with many EMI variables.

c) A clear understanding of the purpose for which measurements are to be

made is important (and has frequently been missing in the past) prior

to the start of a measurement program.

d) In general, the technology required to develop needed instrumentation

is available, but it has not been reduced to commercially available

devices.

e) The traditional reliance on measurement of some characteristic

relative to an arbitrary standard is to be avoided in the future

wherever possible. Such an approach provides very limited

understanding of underlying causes and inhibits extrapolation to more general situations.

f) New and improved measurement guidelines (as opposed to formal

standards) are considered helpful and needed.

As noted elsewhere, there was a broadly felt need for improved

guidelines and voluntary standards, but there was also a concomitant aversion

to regulation and mandatory standards. Concerns concentrated on guidelines

for the measurement of the EM environment and of the susceptibility of

electronic equipment. The measurement question appeared as a semantic

convenience. At the conclusion of the sessions, the emphasis appeared to be on the definition of selected EMI characteristics, whether through

measurement, analysis, or a combination of the two. The practical approach

to "measurement" topics involves the judicious combination of measurements

and analysis —an approach as demanding of guidelines and standards as either

of the others.

5. PRACTICAL SOLUTIONS TO IDENTIFIED PROBLEMS

Identified problems were not heavily technology dependent and the

practicality of various solutions (or approaches to solutions) was very

uncertain. Solutions considered included increased educational efforts and

improved organization and coordination among government agencies. The

educational need applies both within the EMI community and the public at

large. A general air of pessimism characterized the group's feelings toward

the prospects of improved government interagency coordination.

Solutions to the problem of improved environment definition included

both prediction and measurement, neither of which was defined specifically

enough to assess the practicality of developing such results. The Canadian

proposal in their EMI Advisory Bulletin was offered as one possible approach.

6. BASIS FOR ACTION

Within this group there appeared to be very little agreement as to a basis for future action beyond the identification of a partial list of needs.

Foremost of these needs was an improvement in the institutional arrangements

for dealing with EMI. A more cohesive and readily understood program was strongly urged by most participants. Other needs, addressed elsewhere in this

summary, include definition of environment, development of confident exposure

25
criteria, better education of active participants as well as the general

public, and some consistency in regulations, standards, and guidelines.

The consensus was that technology does not represent a significant

barrier to the problem solutions, although there is a continuing need to

improve on measurement methods and instrumentation.

7. PRIORITIES FOR PROBLEM SOLVING

At the end of the second session, the group drew up a set of four

resolutions as a means of focussing the concerns of the group and of

identifying priorities. The document prepared is reproduced here:

Draft Resolutions from the Communications Working Group

BE IT RESOLVED THAT:

1. The government shall provide industry with EMI profiles to facilitate

design, engineering, and marketing of consumer and industrial products.

2. The government shall determine "safe" levels of electromagnetic exposure

for people. Further, the government will not adopt mandatory personnel

exposure levels until maximum safe levels have been established.

3. Government and industry shall promote consumer education with respect to

EMI

4. Standards and regulations shall be consistent and uniform on a national

and international basis.

26
TRANSPORTATION WORKING GROUP SUMMARY

Ronald J. Wasko

Motor Vehicle Manufacturers Association

Detroit, Michigan

1. PROBLEM AREAS

During this workshop there was considerable discussion about the content

of the electromagnetic environment,

including how the environment should be

defined. Generally, attendees determined

that there was a definite need to define

the electromagnetic environment, but

characterizing the environment was another

matter. After considerable discussion, it

seemed that a definition of the environment

should not be made on a basis of a time/level average because designers of

equipment need to know the instantaneous

peak values of the electromagnetic

environment to insure proper product

compatibility within the environment. This

type of definition would require almost

continuous measurement and vector analysis

of the E or H fields. Also, there is a definite need to provide appropriate design

goals by technical societies and voluntary

standard groups. Currently there are confusing and conflicting standards such as the ANSI Standard for design

specifying a one volt per meter field strength requirement to meet

compatibility requirements, whereas the Canadian government has set other

levels

.

Overall, the need to define the environment seems paramount.

Attendees also expressed a definite need to develop electromagnetic test

procedures that manufacturers need to insure product compatibility.

Specifically, most manufacturers are working on products that will be

introduced in three or four calendar years. The electromagnetic environment

may change in that timeframe and representative, accurate test procedures for

measuring electromagnetic environments that the products will be exposed to

should be available now. Additionally, most products will be in the field

several years after introduction and the expected electromagnetic

environment, throughout the operational lifetime of the product, must be

known to insure compatibility.

2. CRITIQUE OF THIS WORKSHOP

The working group sessions would have been more useful if more Federal

regulatory agencies had attended and participated. The National Highway

Traffic Safety Administration has indicated an intent to regulate motor

vehicles for electromagnetic emissions/compatibility in the future. Also the

United States Environmental Protection Agency has been making measurements on electromagnetic levels in cities throughout the United States.

To permit users and manufacturers of equipment that might be regulated

at a future date to understand the regulatory philosophy, a dialogue with

regulators is needed. Unfortunately, the regulators were not in attendance

at the working group sessions, although they were requested to attend. In

addition, the National Telecommunications and Information Administration

(NTIA) was requested to participate because the Federal government allocates the

27
electromagnetic spectrum and transmitter power. This agency should have

information on how to map the electromagnetic environment. Once again, NTIA

was conspicuous by its absence.

In a connected note, it was apparent from conversations at the workshop

that the Federal Communications Commission personnel in attendance were not aware of the fact that the National Highway Traffic Safety Administration

might be regulating products for electromagnetic radiation/compatibility.

3. FUTURE EMI WORKSHOPS

On the subject of future workshops, this working group did not provide a definite answer if another workshop is needed. An expression of concern was

that without discussion of all the appropriate parties who are involved in

transportation, electromagnetic test procedures, and future possible

regulations, the definition of a specific problem could not be reached.

However, the feeling that the electromagnetic environment needs to be defined

was strong and pervasive.

Although there was no definite feeling within the group if another

workshop should be held, several opinions were endorsed by the group. These

are

a) The proceedings from this workshop must be published to provide a continuum of information on electromagnetic radiation and future

activities in this area.

b) There was a definite indication that a need to include all

transportation sources should be included in any future workshops

because problems common to surface transportation may not be

applicable to aircraft, watercraft, or rail transportation. A

definite need exists to have all of these functions involved in any

future workshop.

c) Another suggestion that received very strong support from the group

was that any future workshops revolve around concerns rather than

working groups divided by product classification. Concerns such as susceptibility, radiated emissions, regulations, etc., would provide

all parties attending a workshop to enter into an overview and

interaction with other parties who would be affected by the same concerns. An obvious conclusion of the transportation sessions was that the equipment impacted by motor vehicle radiation, namely land

mobile communication equipment, was not represented in the

transportation session, but rather was included in the communications

session. Therefore, the views and considerations of the

communications industry could not be incorporated into the

transportation session.

d) If future workshops were structured around concerns, a more appropriate use of available time would be to solicit questions to

determine the concerns of the group prior to the workshop. In this

manner, pressing questions could be concentrated on. Obviously this

would take some extra work, but the end results should be

worthwh il e

.

4 . SUMMARY

In summary, there is a definite need to understand and define the

electromagnetic environment to permit manufacturers of products to operate

within the electromagnetic environment. If the design targets are known,

products can be made to live within that electromagnetic environment.

28
CONSUMER PRODUCTS WORKING GROUP SUMMARY

W. Thomas Collins

RCA Corporation

Indianapolis, Indiana

The Consumer Products Working Group

addressed the EMI problem areas by means of

a panel, with each panelist briefly

commenting on the problems as perceived

from his or her viewpoint. Following those

comments the floor was opened for

interaction between the panel and

attendees

.

A major part of the Consumer Products

sessions was devoted to the radio-frequency

aspect of EMI with the focus on TVI

involving CB radio emissions and television

susceptibility.

Some background is helpful relative to

the change in the interference "profile"

between the late 1940 's and the recent

past. Then, before any impact from

television, the number of RFI complaints

(generally involving audio rectification)

was fairly small (of the order of 7,000 to

8,000). The situation changed dramatically

though in the late 1960's and early 1970's.

The change was due in large measure to two

things —the growing use of home entertainment

life, and a tremendous surge in CB radio sale:

Currently there are about 120 million TV receivers in use in the United

States plus another 400 million radios and millions of other electronic audio

products. The surge in CB sales quickly converted to a consumer product that

which had been considered by many to be an industrial type product for

trucker and other business use. By the end of 1977 the number of CB licenses

had grown dramatically to about 16 million as had the number of RFI

complaints—about 80,000 according to the FCC.

To come to grips with the problem and identify problem areas, the FCC:

a) Increased the CB transmitter harmonic suppression requirement from 49

to 6 0 dB.

b) Invited comments on a further increase in harmonic suppression to

100 dB.

c) Established a Personal Use Radio Advisory Committee (PURAC) to

provide information on RFI and other aspects of CB use.

d) Undertook, through its Field Operations Bureau, an in-depth analysis

of some 72 randomly selected interference complaints.

e) Initiated rulemaking proceedings to ban the use of linear amplifiers

designed for use in the 24-35 MHz band and to bring amateur radio

equipment under its type-acceptance program.

^1

products in the public's daily

29
What have these actions and studies yielded in terms of problem

identification and priorities? There are several problem areas that have

been identified.

a) The most significant problem involves the illegal use of linear

amplifiers which boost the allowable 4 watts to output power

many-fold. Linears can cause two kinds of problems—overload of the

front end of the television receiver across a substantial portion of

the band (despite high-pass filtering at the television receiver) and

harmonic interference (most prevalent on channels 2 and 5 which

include the 2nd and 3rd harmonics of the 27 MHz CB transmitter).

Harmonic signals falling within the passbands of television stations

operating in the area cannot be filtered or "stripped out" without at

the same time stripping out the desired television signals.

b) A lesser (but still significant) problem involves the adequacy of the

present 60 dB harmonic suppression requirement which is applicable to

the signal appearing at the antenna terminals of the CB transmitter.

c) A related problem is CB chass is radiation of harmonically related

signals. This has not been adequately addressed and the problem

cannot be handled by installing a low-pass filter.

With respect to solutions, there again are several:

a) The ban on the sale of linear amplifiers should address complaints

involving future sales. As to amplifiers sold before the effective

date of the ban, this can be handled in two ways with the FCC taking

the lead. One is an educational campaign, with the catalyst being CB

clubs and organizations, to communicate to the uninformed the

illegality of using linears. As to those users who persist, there is

FCC enforcement which necessarily, because of personnel and budget

constraints, must be on a "rifle shot" basis with enforcement

publicized to deter others.

b) On the harmonic suppression requirment, CBer's and television

manufacturers do not agree on the amount that should be required.

Proposals range from the current 60 dB to 100 dB with the most likely

compromise somewhere between 70 and 90 dB. Many believe the proper

amount of suppression should be nearer 90 dB, but the FCC has not

taken any action for some time on the open rulemaking proceeding.

c) Basically the same criteria (applicable to antenna harmonic

radiation) should be extended to chassis radiation. This necessarily

would have to be taken care of in product design and not later. For

the 2nd and 3rd harmonics the chassis equivalent of 90 dB would be

63 v/m at three meters.

d) With these steps being taken, together with efforts of television

manufacturers to reduce receiver susceptibility, it is believed

further regulatory action (e.g., the Goldwater, Vanik, and Benjamin

bills) is unnecessary. Television manufacturers continually are seeking to reduce susceptibility and are employing new types of

instrumentation toward that end (e.g., the TEM cell) even though no techniques are presently available to cover the entire spectrum.

As to the possible long-range solutions to the problem, there are technological constraints as well as constraints on suitable test standards

and methodology. As present solutions are implemented, the EMI problem

should diminish with time, but it is doubtful if it will in the near term

retreat to pre-1970 levels. This appears to be recognized by the FCC which

was considering a new CB service in the 220 or 900 MHz bands. The FCC is

reported to favor the 900 MHz band and it remains to be seen what the

30
implications are as to availability of technology and equipment cost. It

also remains to be seen whether the present Class D service at 27 MHz would

be continued or phased out.

Other problem areas were discussed in the Consumer Products sessions.

These included:

a) The lack of adequate test standards and instrumentation to make good

EMI measurements. This applies not only to present products and

systems where various standards and measurement methods have

limitations, but also to future systems likely to exist in the

1980's. One current problem area touched on in several sessions

during the overall Workshop involves the interference/susceptibility

interaction between the fairly new home computers and other

electronic products found in the home. Another problem discussed is

the impact EMI is likely to have on home major appliances using

microprocessors. And there was discussion of EMI problems to be

addressed in new systems (e.g., carrier current systems) where home

wiring would be the vehicle for control of appliances.

Many believe that an organization such as the National Bureau of

Standards is best equipped to lead the way on new measuring methods

and instrumentation. This task, for the most part, was considered to

be not within the resources or capabilities of individual companies.

b) How one would characterize the signal being measured. Average?

Peak? Average Log? No consensus was reached on this topic.

c) The lack of an "interference profile" for any extensive geographical

area. (This was discussed in several Workshop sessions). Acquiring

this information could be costly, and the fast pace of technology and

other changed conditions could change the profile. Even so, one view

was expressed that a profile might be useful for other purposes, as for example to respond to critics who contend "EMI pollution" has

reached the point where it would adversely affect health and safety.

d) A considerable amount of time was spent on the subject of educating

the consumer on EMI. This discussion addressed a number of facets:

The extent of awareness (if any) the consumer had as to EMI; the lack

of choices existing for consumers when purchasing electronic products

(should various characteristics of consumer products be emphasized,

highlighted, graded, labeled?); the ability of consumers to "digest"

and evaluate the relative significance of these characteristics; and more typically, what information now exists which would aid a consumer in resolving an EMI problem "in being".

With respect to RFI in television and audio products, specific

discussion was directed to a booklet published by the FCC entitled "Radio-TV

Interference Problems" and to two Interference Handbooks published by the

Consumer Electronics Group of the Electronic Industries Association for use

by the service technician (not the consumer). One was directed to resolution

of television interference problems and the other to resolution of

interference problems in audio equipment. The FCC booklet is available to consumers as well as service technicians, and contains a number of possible

solutions which would require implementation inside the television receiver.

Some discussion, therefore, centered on the extent to which a consumer might

be injured in attempting to pursue one of these remedies.

31
INDUSTRIAL WORKING GROUP SUMMARY

George H. Hagn

SRI International

Arlington, Virginia

1. INTRODUCTION

Three workshop sessions on industrial

EMI were organized by the author. A panel

format was used which included considerable

audience participation. The following is a summary of highlights from these

sessions.

2. PROBLEM ASSESSMENT

The first task undertaken was to

define "industrial" for the purposes of the

workshop. It was agreed that this field

would include process control (including

machine tool control and assembly lines);

information processing (including computers

and peripheral devices); RF heating and

diathermy; welding; construction and

mining; electrical power generation,

transmission and distribution; and the

industrial tools which use electrical

power

The initial discussions involved

defining the problem by several examples. One example given by Shulman

(Foxboro Co.) involved a portable radio transmitter (handle talkie) which

caused an entire refinery to shut down, costing hundreds of thousands of

dollars per day. The industrial area is characterized by many large users of

rather sophisticated equipment and the cost impact of EMI problems can be

very large. Visek (Sperry Univac) noted that the evolution of the computer

has brought about several other categories of difficulties. For example,

several years ago computers were designed to operate in carefully controlled

environments (e.g., air conditioned screened rooms). Today the trend is

towards more distributed processing and small stand-alone microprocessorbased systems. These information processing systems are exposed to a considerably larger range of environments, most of which are not under the

control of (or even known to) the component or systems designer. Keiser

(Consulting Engineer) noted (via a letter to the session organizer) that many

computing machines are susceptible to powerline transients that last more

than 0.1 second and cause the supply voltage to vary by more than 10 percent.

Such transients are caused by lightning and load changes. Uninterruptable

power supplies provide relief, but they tend to be expensive. Motor

generator sets are useful for outages less than 1 second. Chartier

(Bonneville) noted (via a message to the session organizer) that corona noise

from high-voltage (>100 kV) power lines has caused some problems to AM

broadcasting. Corona noise can be reduced by line design, and the economic

trade-off is significant. While the corona loss is only about 5 percent of

the conduction current loss, the rising cost of energy may eventually make it

economic to have quieter lines. Lower voltage (<100 kV) lines can produce

noise from arcing gaps (a problem to some TV and radio receivers); however,

these gap sources on both higher and lower voltage lines can be fixed by

maintenance. Gauper (General Electric) noted the interaction between devices

and EMI; and, as an example, he cited ground-fault-circuit interruptors which

are susceptible to interference to the extent that they can close down a construction or mining site. Schlicke (Interference Control Co.) noted the

32
technical problems caused by the lack of a common ground point in many

systems, long and unfiltered power cables, and filter specification problems.

Garlington (Sprague Electric Co.) noted that filters are designed to work

into specific impedances but they are frequently used with a variety of

different source and load impedance (which may not even be known) . This can result in a filter not providing the required isolation between a source of

conducted interference and the victim system. Shulman noted that filter users don't know how to test filter effectiveness in real-world systems or environments and that standards don't reflect real world conditions.

After a heated discussion on filters, the panel chose another approach

in an effort to define the issues and related categories of problems, such as

a) technical, b) legal/political, c) educational, d) economic, and

e) standards development and coordination. The discussion of these subjects

is summarized below:

a) Technical Aspects

The panel and audience had predominantly technical backgrounds, so the

initial discussions focused on the technical matters. One point made by many

of the attendees is that the electromagnetic environment is not well

documented in a form useful to system designers and analysts. Also, the

environment seems to be constantly changing, and this implies the need for

a statistical description. Perhaps generic example environmental categories

could be defined which can be modeled or simulated for test purposes and used

as part of design guidelines or standards.

The filter discussion illustrated the need for better dialogue between

manufacturers and users, and also for more descriptive data sheets to

facilitate that dialogue. There is also the problem of how to apply a systems approach within a system and between systems. When a digital

engineer, using circuits that switch at 70 MHz, has no knowledge of rf design

practices (or his need for them) , there can be an interference problem which

only becomes apparent when integrating a system. Also, when a source of EMI

belongs to one system (e.g., a power generation plant) that causes a problem

to another system (e.g., the communications control system in a large

refinery) , there are the problems of separation of the planning as well as the ownerships of the source and the victim. Showers (Univ. of Penn.) noted

that, over the years, there has been extensive cooperation between power

companies and telephone companies in solving the inductive interference

problem in those cases where power lines and telephone lines run along the same right-of-way.

b) Legal/Political Considerations

This leads to the legal problem of responsibility for resolution of EMI

problems. Who pays for the fix? The manufacturer of the source, the

manufacturer of the victim system, or the user with the problem? Perhaps the

environmental data existed which could have helped the system designer

avoid the EMI, but company proprietary (or in certain rare cases, anti-trust)

considerations precluded its being shared by the industry involved. Another

legal issue involves the need, and also the threat, of regulation. The

attendees agreed with Herrick (Texas A&M Univ.) that regulation is a weak

attempt at a solution to EMI problems; it can never "solve" them. The group

consensus was that voluntary standards should be tried, and regulation should

be avoided if at all possible.

c) Educational Needs

Numerous education problems were mentioned. How does a young engineer

get information or answers to EMI problems? How do you educate users enough

to be able to talk to manufacturers or their representatives? A distinction

was made between the relatively sophisticated users and the technically

33
unsophisticated user. How do EMI engineers educate their own management to

the importance of considering (and budgeting for) sound EMI design? The main

motivators of management seem to be the threat of what the competition is

doing, the threat of an unhappy customer, the threat of government regulation

and economic considerations.

d) Economic Impact

In the economic area, there are problems resulting from the lack of

adequate information to make cost-risk and cost-benefit trade-offs. There

are many dimensions of risk, including the risk of litigation. The quality

of measurements needed for a given standard is frequently unknown, and this

uncertainty presents a problem with strong economic impact. Also,

conflicting EMI standards exist and pose a different type of economic

problem. For example, such standards can be used as non-tariff barriers to

trade.

e) Standards Development and Coordination

The development of meaningful standards is a problem in its own right;

likewise, the coordination problem. Many groups and committees are active in

EMI/EMC work at the industrial, national, and international levels. Who

should coordinate these efforts? What degree of coordination is practical?

In summary, the problems are of a diverse nature with economic,

technical, political, legal, and educational aspects. The problems in the

industrial area are very serious, especially from an economic standpoint.

EMI can cause the loss of hundreds of thousands of dollars from a single

occurence of the degradation of performance to a control process. Standards

can cause an impact on our balance of payments due to their use as non-tariff

barriers to trade. These standards and the measurements that underlie their

enforcement should be tackled first, in conjunction with a better definition

of the electromagnetic environment and design guidelines for how to use the

information. Work is needed on both emissions and on susceptibility (or

immunity), and the trade-offs should be made from a systems point of view so that sensible economic decisions can be made.

3. SOLUTION ASSESSMENT

The solution assessment session was conducted jointly with the Consumer

Products Group organized by W. T. Collins. This summary will address the

industrial aspects of the discussion.

Industry prefers voluntary standards to regulation, but there is a valid

question regarding criteria for limits and for measurement procedures and

measurement quality. To facilitate the proper technical and economic

trade-offs, there is a need to relate voluntary emission and susceptibility

standards

Copies of the new Scientific Apparatus Makers Association (SAMA)

Standard PMC 33.1-1978, "Electromagnetic Susceptibility of Process Control

Instrumentation," were provided to the attendees by Shulman. He mentioned

that pressures from customers rather than from the Congress or FCC had caused

the standard to be prepared. Twenty (20) percent of the customers provide

eighty (80) percent of the process-control market, and these large customers

have real clout. The small individual consumer has relatively much less

clout, and hence he must complain to the FCC.

The effectiveness of voluntary standards was discussed. One view was that they are effective if they forestall regulation, and it was noted that

they would not be very effective if they were too expensive to check

compliance because of unduly complex measurement requirements. It was noted

34
that each industry has mostly responsible members who plan to stay in

business for a long time. This group needs educational materials, and would

use them. A fear was expressed that a few fly-by-night firms might trigger

regulation that would add cost and not be needed by the larger segment of

responsible industry.

The following current FCC dockets which apply to the industrial area were discussed:

Docket 20780

(NPRM)*

(Part 15)

Docket 20990

(NPRM)

(Part 15)

Docket 20746

(NPRM, MOO, FRO)

(Part 15)

Docket 20718

(NPRM)

(Part 18)

Restricted Radiation Devices and Low

Power Communication Devices

Remote Control and Security Devices

Technical Specifications for

Receivers

Industrial, Scientific, and Medical

Equipment

Docket 21371

(NPRM)

(Part 2)

Measurement Facilities

Docket 78-369

(NOI)

Susceptibility (in preparation

3 Nov. 78)

It was suggested that the government could help by providing an environmental definition or description which could be useful to many

industries, and so no one industry would have to bear the cost burden of

acquiring this information. The company proprietary problems regarding

sharing data on the environment would also be overcome by this approach.

Certain insurance-related problems could be mitigated.

Regarding consumer (user) education, susceptibility limit tables versus frequency might be useful. Then an educated consumer could determine how

much protection he was paying for and make a better risk assessment relative

to the environment of his planned use. It was noted that this would only

work for relatively knowledgeable consumers. Special attention was devoted

to the Notice of Inquiry (NOI) on susceptibility that will be printed before

the end of the year if the FCC follows the staff recommendation.** Jones

(FCC) emphasized that the NOI will seek to answer the question of whether or not the FCC should be in the susceptibility business, not how should they

regulate susceptibility. She indicated that copies would be provided to the

workshop attendees, and she expressed the FCC ' s hope for a good response to

the NOI during the proposed 6-month comment period.

Various FCC publications were discussed as part of a broader discussion

of education. Browne (EIA) commented on some shortfalls of these

publications. One solution seemed to be to have the information available

* NPRM = Notice of Proposed Rule Making

MOO = Memorandum of Opinion and Order

FRO = First Report and Order

NOI = Notice of Inquiry

** This became Docket 78-369 several weeks after the Workshop.

35
written at various levels (e.g., 6th grade education, high school,

technician, engineer, etc.). Showers noted that undergraduate curricula were already too full to include much on EMC; however, there was a need for

graduate classes. The universities need to know what industry expects from

their graduates.

The general problem of who should carry the responsibility for the

solutions and what roles should be played by government, industry, and

educators was noted to be very complex; it was not resolved.

4. WHAT'S NEEDED FOR PROGRESS

The final working group session addressed the question of what is needed

for progress. Discussions are summarized below.

It was the consensus of the group that better measurements were needed

for progress, along with a better understanding of how to use the results of

the measurements. A presentation was made by Vincent (Systems Control, Inc.)

who showed results of environmental electromagnetic measurements made with a 3-dimensional display of peak-detected level versus frequency and time. He

showed that vinyl plastic welders are frequently used at high power levels

outside their assigned industrial-scientific-medical (ISM) bands. These

devices (and similar ones) caused interference to communications systems, and

this was perceived as an FCC enforcement problem. It was noted that they were operated out of a band in some cases because they were more efficient

when operated there, and this was perceived as an equipment design problem in

part. Vincent mentioned that on one occasion he made 2000 observations of

ISM equipments per hour at 18 MHz and 1500 per hour at 21 MHz. (Both

frequencies are outside the ISM frequency allocations.) The changing nature

of the environment (discussed in earlier sessions) was graphically

illustrated on a time scale of several seconds. Especially noted was that

the narrowband instrumentation in common use was not well matched to the

problem of documenting such a dynamic environment.

Middlekamp (FCC) summarized some of the goals and findings of FCC Docket

21371 on measurement facilities. He indicated the desirability of test

ranges which could provide repeatable results at the FCC laboratory and at

manufacturers' plants without undue cost. A 3-meter separation was suggested

for VHF and UHF to save space where land was very expensive. The importance

of mutual coupling effects for such spacings was emphasized. He mentioned

that FCC reports on this work will be published.

Crawford (NBS) pointed out that to make progress in assuring EMC we must

first know what the EM environment is (including time and location

variabilities). We must then be able to simulate it accurately and

repeatably for susceptibility testing purposes; and be able to meaningfully

evaluate the effects of the environment on victim systems. Also, the

definition of what constitutes a system, or victim, must be sharpened and

agreed upon by both users and producers.

A discussion of where to obtain information on EMI/EMC was initiated,

and several categories were listed:

36
Publications:

Books

IEEE EMC-S Transactions

IEEE EMC-S Newsletter (including abstracts)

IEEE noise guides (e.g., IEEE Std. 518-1978)

SAE-AE-4 publications (SAE J551, SAE J1113A)

EIA (C-46) design guides

ANSI standards (e.g., C.63.2, C63.4, and C63.12)

CISPR publications (available through ANSI)

URSI "Review of Radio Science," published every 3 years

ITEM, published by R&B Enterprises

Seminars (e.g., Don White Consultants, etc.)

Classes at Universities

Bernie Reiser's at George Washington U.; others at Texas A&M , Georgia

Tech, U. of Colorado, U. of Pennsylvania

The need for a complete list of these resources and their availability

was emphasized by Thomas (Thomas Engineering). It was generally agreed that

when most engineers had a problem they called someone they thought knew more

about the area than they did.

Finally, the question of what is the state-of-the-art of EMI

measurements was briefly addressed. EMI measurements were divided into two

broad categories: Conducted and radiated. Vincent's presentation was indicative of the state-of-the-art for conducted and radiated emanations

measurements when using conventional transducers with repetitive-sweep

spectrum analyzers, peak detectors, and a 3-dimensional display. This

technique has an estimated absolute accuracy of + 6 dB. Crawford suggested

that the most accurate (state-of-the-art) techniques for susceptibility

(immunity) testing are: a) The generation of planar far fields in anechoic

chambers at frequencies above 200 MHz, determined by the size of the chamber

and characteristics and placement of the absorber; and b) the use of TEM

cells at frequencies below 200 MHz. The upper frequency of the TEM cell is

determined by the size of the equipment to be tested and hence the size of

the TEM cell used. These two techniques have estimated absolute accuracies

of + 1 to + 3 dB, depending on the frequency and size of equipment tested.

37
MEDICAL WORKING GROUP SUMMARY

James C. Toler

Georgia Institute of Technology

Atlanta, Georgia

1. INTRODUCTION

At first glance, it appears a little

strange to have a bioeffects or medical

session at an electromagnetic interference

(EMI) or electromagnetic pollution

workshop. A major part of this

"strangeness" stems from the fact that, in

its common usage, the term "bioeffects"

refers to the health hazards, either real

or postulated, resulting from biological

system exposure to electromagnetic

environments. There are, of course, entire

conferences and symposia devoted to this

complex subject. Attendees at these

conferences and symposia are generally

quite a different group of people from what

one finds at an EMI workshop.

But if we look deeper, we see that our basic concern is the compatibility of

systems with their operational electromagnetic environment. This was certainly the case in the medical sessions at this

workshop. Within the EMI community, the

systems of interest have traditionally been those used in military electronic

applications —radar, communications, avionics, navigation, etc. More

recently, there has been some involvement with the electromagnetic

susceptibility of certain medical and consumer electronic devices. This

involvement has resulted in measurements being made to define the

susceptibility characteristics of a large number of cardiac pacemakers and a small number of televisions, radios, etc. Also, at least one electromagnetic

performance standard for medical electronic devices has been generated.

Outside the EMI community, where compatibility of systems with their

electromagnetic environment has been a concern, the systems have generally

been biological in nature. It has been the compatibility of these systems

with their electromagnetic environment that has come to be termed

"bioeffects." Although the systems and investigators differ, the basic concern with the ability of systems to function reliably and without

degradation in their operational electromagnetic environment is still the

primary subject of interest.

So, from this perspective, a bioeffects or medical session at this EMI

Workshop was considered to be very appropriate. In this working group, the

effects of electromagnetic environments on the performance of both medical

electronic systems and biological systems were considered; however, the fact

that the two systems are electromagnetically quite different was recognized

from the outset and questions, comments, presentations, etc., were tailored

to the appropriate system.

2. SESSION APPROACH

The session format was one in which invited presentations were made at

the beginning of each session period. These presentations were followed by

discussion periods during which specific questions were addressed. The

invited presentations were as follows:

38
Session I, Thursday morning

Session Introduction and Overview

J. Toler, Georgia Tech

Activities of the IEEE Committee on Man and Radiation

D. Justesen, Kansas City VA Hospital

Considerations in the Development of Medical Device Standards

L. Hamilton, Health Industries Manufacturer's Association

Session II, Thursday afternoon

Activities of the American National Standards Institute

S. Rosenthal, New York Polytechnical Institute

Evolution of EMI Standards for Medical Electronic Devices

B. Flink, Medtronic, Inc.

Session III, Friday morning

Electromagnetic Susceptibility of Medical Electronic Devices

B. Jenkins, Georgia Tech

Beneficial Applications of Electromagnetic Waves

F. Cain, Georgia Tech

Typical questions that followed these presentations were:

Are regulatory and/or legislative actions, i.e., standards, necessary to assure that electromagnetically-safe medical electronic systems are offered

to the public?

What EMI standards now exist for medical electronic systems?

What EMI standards now exist for bioeffects?

Is compliance with these standards compulsory or voluntary?

Should compliance with these applicable standards be compulsory or voluntary?

What organizations generated the applicable standards for medical electronic

systems?

What organizations generated the applicable bioeffects standards?

Do these organizations have the technical expertise necessary to generate

valid EMI standards?

Who should be responsible for generating EMI standards for medical electronic

systems?

Who should be responsible for generating EMI standards for bioeffects?

How should these standards be updated?

What changes are needed in the existing EMI standards for medical electronic

systems?

What changes are needed in the existing EMI standards for bioeffects?

Which of these changes is the most critical?

What research needs to be undertaken in order to develop improved

requirements for existing standards?

39
Who should bear the cost of this research?

How do U.S. EMI standards for medical electronic systems and bioeffects

compare with counterpart standards in other countries?

3. SESSION CONCLUSIONS

Primarily because of the technical and employment diversity of the

session attendees, it was difficult, if not impossible, to unanimously agree

on any question of major importance. In general, the divided opinions

involved persons associated with the design/manufacture of medical

electronic systems and the operation of electromagnetic sources disagreeing

with other session attendees; therefore, all conclusions were drawn from

consensus opinions that appeared to reflect feelings of the majority. These

opinions are summarized as follows:

a) There should be regulatory and/or legislative actions, i.e.,

standards, to assure that (1) electromagnetically-safe medical

electronic systems are offered to the public, and (2) ambient

electromagnetic environments in public areas are not capable of

causing harmful biological effects.

b) In the area of medical electronic systems, thoroughly-defined and

well-documented instances of life-threatening EMI problems are almost

non-existent. This situation exists in spite of the fact that the

U.S. Army's Environmental Hygiene Agency has a procedure by which

such EMI problems are to be documented and reported. Few of the

session attendees —other than those from the Environmental Hygiene

Agency--were aware that a reporting procedure for EMI problems with

medical electronic systems existed. Instead of 1 if e- threatening EMI

problems that are thoroughly-defined and well-documented, there are myriad reports which are verbally circulated. These reports are often emotional in nature and have tremendous possibilities for

inaccuracy and exaggeration.

c) In the area of biological systems, thoroughly-defined and

well-documented instances of athermal , life-threatening EMI problems

in man are essentially non-existent. However, this is an area in

which EMI problems may manifest themselves in subtle and

dif f icult-to-detect ways; therefore, most session attendees did not

feel qualified to present strong opinions as to whether athermal,

life-threatening EMI problems exist in man. The fact that EMI

effects may exist in biological systems without being hazardous was duly noted. It was also noted that research has revealed certain

hazardous effects in experimental animal models; however, there was uncertainty as to whether these effects would be extrapolated to the man model.

d) Existing EMI standards for medical electronic systems are limited to

the pacemaker standard developed by the Association for the

Advancement of Medical Instrumentation (AAMI). The medical device

EMI standard recently developed by the Food and Drug Administration

is available for "guidance," but is not imposed on a mandatory

compliance basis. The AAMI standard was developed via a consensus procedure that included inputs from both engineering and medical

professionals. Compliance with the requirements of this standard is

voluntary and essentially all pacemaker manufacturers comply with the

standards

.

e) Existing EMI standards for biological systems are limited to the

document titled "Safety Level of Electromagnetic Radiation with

Respect to Personnel." This standard was developed by the American

National Standards Institute (ANSI). Like the AAMI pacemaker

40
standard, the development of this standard was via a consensus

procedure. Compliance is voluntary and a five-year schedule for

review, update, and/or withdrawal is used by ANSI. The rationale for

the 10 milliwatts per square centimeter level of safe exposure for

personnel was discussed at length. Similarly, the possible rationale

for the much lower exposure levels advocated by Eastern European

countries was also discussed. It was noted that ANSI does not fund

research but uses experts having knowledge of current research to

develop their standards.

f) It was generally felt that EMI standards for both biological and

medical electronic systems should be developed out of a consensus opinion approach in which experts from engineering, biology, and

medicine fields would have the opportunity to provide inputs.

Difficulties with this approach were noted, especially in terms of

securing the time and travel funding necessary for individuals to

adequately contribute their expertise. To the extent possible, this

approach to standards development should be patterned after the

successful efforts of AAMI in their generation of the pacemaker EMI

standard.

g) It was also generally felt that compliance with the standards should

be voluntary. Such compliance would result in a more cooperative

attitude toward compliance and should reduce situations of dogmatic

insistance on compliance in cases where requirements in the standards

are nonapplicable. Although compliance with the present bioeffects

EMI standards is voluntary, noncompliance with its requirements would

be widely viewed as unacceptable.

h) There should be some well-publicized mechanism established by which

EMI problems with medical electronic systems can be compiled and

maintained. The lack of specific information on these problems makes

it almost impossible to determine the need for an EMI standard for

medical electronic systems.

i) To the maximum extent possible, EMI standards generated for either

medical electronic systems or biological systems should be tailored

to specific problem areas. General standards applicable to broad

frequency ranges and essentially all performance parameters were considered unjustifiable. All standards should be accompanied by a detailed rationale report that documents why the standard is

necessary and the technical basis from which its requirements are derived. The extent to which unwarranted standards burden

manufacturers and limit their ability to compete in international

markets was noted.

j ) The critical need for more research in the area of EMI in biological

systems was repeatedly discussed. There seems to be no overall

coordination of research efforts in this area, with the result being

(1) each funding agency continues efforts without appreciable regard

for what other agencies have or are doing, (2) the funding available

for research is small and fragmented, and (3) research methods of

approach are often sloppy to the point that results are of

questionable value.

k) There is a critical need to educate both manufacturers and users of

electronic systems regarding EMI principles. Manufacturers need to

understand interference sources and suppression techniques so more emphasis can be placed on a priori elimination of EMI by design

rather than a posteriori reduction of EMI by testing.

41
PLENARY SESSION IV SUMMARY

"THE LAST, LAST WORD"

M. Gerald Arthur

National Bureau of Standards

Boulder, Colorado

Following the summary presentations by

session developers, reported in the

preceding pages, the workshop chairman

opened the final plenary session to free,

unstructured discussion in which the

attendees were encouraged to ask questions

and make comments. The following material

is a report of those discussions as extracted from hand-written notes.*

1. FCC NOTICE OF INQUIRY

Krauss (FCC) announced to the assembly

that a copy of the FCC notice of inquiry

(NOI ) on radio frequency interference to

electronic equipment will be mailed to each

person registered at the workshop.

(Editor's note: This was released

November 21, 1978 as General Docket No.

78-369. ) Appended to it will be a copy of

the Canadian document "Electromagnetic

Compatibility Advisory Bulletin--Immunity

of Electrical/Electronic Equipment Intended

to Operate in the Canadian Radio

Environment (0.014-10,000 MHz)" issued by

the Telecommunication Regulatory Service on September 1, 1977. The FCC NOI

deals with interference, compatibility, and susceptibility in broad terms,

but does not deal with bioeffects (this is to be the subject of a separate

NOI). Information about this or any other FCC activity may be obtained from

the FCC Consumer Assistance Office, telephone (202) 632-7000,

Washington, D.C.

2. EMI ENVIRONMENTAL DATA

Showers (U. of Penn. ) opened a discussion on the issue of EMI

environmental data acquisition for general use by challenging the claim that

"more" data are needed, citing the large amount of data already gathered by

EPA on radiation levels near broadcast transmitters. Before more or new data

are obtained, the purpose to which it will be put must be defined.

Hagn (SRI) supported this position by citing another example where a large quantity of data was accumulated, but its owners found it difficult to

know how to use it to predict the degradation of a given known system. It is

important to analyze the system to determine what information is needed

before setting out to- take data. So many variables come into play that

non-specific data may be useless. The linkage between the environment and

the victim system must be established.

Showers mentioned that, in this respect, the power line people have been

an exception. They know what their system is and what information is needed.

But this is seldom true in other cases. On the other hand, Collins (RCA) pointed out that for some applications

a reference point is needed from which to move forward; for instance, when

the public health and safety are involved. The automotive industry has been

* Notes were taken, in part, by John F. Mayo-Wells, NBS , Gaithersburg, Md

.

42
one group that believes environmental characterization to be very important

in the designing of safety features on motor vehicles.

Thomas (Thomas Engineering) urged that a list of specific EMI/EMC

information sources be compiled, identifying each document, item, etc.,

providing information on its contents, and where and how it may be obtained.

This recommendation received general approval.

However, Hamilton (HIMA) stated that even if we had a complete and total

description of the environment, he questions whether we would actually know

how to use it. We have much to learn about the effects of the radiation

environment on systems (for example, low-level radiation bioeffects), and it

is not clear at this time what information we need. A proposal to conduct an environmental survey should be recognized as potentially growing into a multi-million dollar measurement program, and therefore we should be clear as to what we expect to achieve.

Altogether, these discussions, along with other scattered comments from

the floor, pulled together and restated the discussions held earlier in the

individual group sessions of the workshop. The pros and cons of conducting a survey of the EMI environment were quite extensively aired. However, the

workshop attendees did not formulate a recommendation for action.

3. CONSUMER REACTION

Miller (NBS) cited the need for getting consumer reaction or involvement

in FCC rule making. But it is difficult to know when such information truly

represents a cross-section of consumers because only a vocal minority may

speak up. How can this be done?

Collins (RCA) agreed that this is a problem, especially since only a minority normally respond, and they may not actually speak for the group they

claim to represent. The problem relates to that of disseminating meaningful

consumer information. This can be done through organizations (e.g., CB

clubs), the press, manufacturers' pack-in information sheets with products,

manufacturers' personal responses to consumer inquiries, and through the

meetings that the FCC holds as part of the rule-making process.

4. "HIGH-LEVEL" VS. "LOW-LEVEL" RADIATION

One of the problems discussed was the (presumed) distinction between

"high-level" and "low-level" radiation. This occurs especially in

discussions of bioeffects. Thus, one attendee asked, "How low is 'low-level'

radiation?"

This was quickly identified as a semantic problem. Hagn (SRI) pointed

out that the meaning of "low-level" varies according to the system in

question. Justesen (VA) said that 10 mW/cm^ would be considered a moderate

level in the U.S. A and a very high level in the U.S.S.R. Levels below 100

MW/cm^ would now qualify as "low-level."

Gauper (GE) deprecated the use of such terminology entirely. We are a multi-disciplinary group, coming from a wide variety of electrical

engineering areas. We should talk numbers instead of relative terms. Then

we would understand each other.

5. PUBLIC RELATIONS

Toler (Georgia Tech) discussed the problems that derive from the bad

connotation that the word "radiation" has in the minds of the public. They

have been conditioned by the press, TV, books, etc., to view radiation as an invisible, odorless threat to their health and safety. Hagn (SRI)

43
supported this thought, pointing out that the role of radiation in science

fiction literature and children's comic books (e.g., "death rays," etc.) has

conditioned people who do not have a technical or scientific background to

misunderstand the true nature of radiation. This problem had been discussed

in the Medical Working Group session, and an unsuccessful effort was made to

find an alternative term that would not have the emotional impact of

"radiation." We can perhaps only acknowledge that the problem exists, and go

from there.

Miller (NBS) raised another problem faced by decision-makers who need to

document radiation effects, particularly bioeffects. He asked how we can make it easy for people to report such effects without in some way putting

themselves under an onus for doing so. By analogy, this is the problem with

UFO documentation. Toler replied that perhaps we cannot make it generally

easy. In certain cases, a reporting mechanism has been set up, as for

example, recipients of implanted medical devices. In other cases, some people who experience bioeffects, or who anticipate such effects, are making

their concern known through lawsuits. The greatest benefit of these

procedures to the decision-maker is that they identify the need for EMI

controls.

6. SUSCEPTIBILITY, EMISSION, AND REGULATION

One attendee observed that much emphasis had been placed on EM

susceptibility during the workshop, whereas the greater concern in other

countries has been with the total amount of radiation that can be safely

emitted. Another attendee agreed, pointing to the New York City proposal

to limit the radiation level from all sources combined to 50 W/cm^. But

enforcement of such an ordinance would be difficult, if not impossible.

Krauss (FCC) pointed out that this is a municipal matter having to do with

the safety and health of the city's citizens, and the FCC would not have any

enforcement responsibility there. The FCC's jurisdiction is primarily

related to EM compatibility. New York City's concerns are far different from

this, and it may well be that a federal agency other than the FCC might

become involved (if at all).

Miller (NBS) asked Krauss if it were not true that the FCC would respond

to any known threat to health that fell under its statutory authority.

Krauss replied that in specific instances where there is a clear and present

danger to health or safety, the FCC will respond through specific enforcement

activities, or through cease and desist orders, or through court injunctions.

In broad, general cases, it is not clear that the FCC would respond by means

of rule-making procedures. Even though the FCC has statutory authority to

correct a known and documented situation that per regulations was at a hazardous level, it is not clear that the FCC would necessarily do anything

about it. Economic factors could affect how the problem might be resolved.

44
CHAIRMAN'S SUMMARY AND CONCLUSIONS

Charles K. S. Miller

National Bureau of Standards

Boulder, Colorado

The preceding papers by the overview

speakers and the session summaries give a good account of what transpired during the

workshop. In addition, the following set

of brief statements captures some of the

concerns of the attendees that are worth

pulling out from the large number of talks

and discussions.

EMI problems are in their infancy by

comparison to what they will be by the

late 1980's (Chris Kendall - private

consultant)

. EMI generated by emitters in ISM bands is

ignored by FCC.

. Would we be better off to move more AM,

FM, and TV to UHF bands and reduce the

power, or reduce the amount of licensed

radiation by reducing power levels or limiting the number of licenses? Must we have all the radiation permitted?

. Adapting Mil Standards 461 and 462 to civilian or consumer electronics

needs is not realistic or meaningful.

. Many changes in technology are taking place because of the use of

electronics

. Compatibility of electromagnetics and electronics has traditionally been

addressed toward communication system needs. Electronics used for control

systems cannot be restricted to the same design constraints (e.g., control

systems have exposed receptors, feedback systems, several analog and/or

digital connecting data transmission lines, etc.). (Paraphrase from

Dr. H. Schlicke - private consultant.)

. Biological receptors exist that are sensitive to weak electric and magnetic

fields (e.g., navigation by fish, birds, and animals).

. Natural fields regulate biological clocks of mammals (including man). We

should, therefore, expect biological EMI to desynchronize such biological

rhythms with their attendant effects. (Paraphrase from Dr. D. Justensen - neuropsychologist with V.A.)

. "Radiation effects" and "radiation hazards" are not the same thing.

. There are beneficial uses of radiated fields, and we must be careful not to

"throw the baby out with the wash."

. EMI problems will grow in number and complexity because trends in evolution

of U.S. economy are spectrum intensive.

. The EM environment must be measured to define present and future

conditions

45
. Education of engineers is lacking in EMI, so latest approaches to solving

these problems are not used.

. Education of public to EMI problems would permit a more general awareness

of the problem and allow us to assess the extent of the problem.

. Conventional EM environmental measurements are inadequate. Instantaneous

peak values are important; statistical data must be gathered; vector

analysis of E and H fields is important.

. CB chassis radiation of harmonically related signals is not addressed by

FCC.

. Further regulation will not solve the EMI problems.

. Cost impact of EMI effects in industry with their sophisticated equipment

is very high (e.g., hundreds of thousands of dollars per day).

. Power line transients lasting longer than 0.1 sec. with more than

+ 10 percent voltage change significantly affect computer-controlled

manufacturing processes.

. We don't know how to test filter effectiveness for real world environments,

and we don't know how our standards relate to such environments.

. You must make a trade-off between test procedure complexity and the

measurement information you get. Are we to double the number of tests by

measuring both electric and magnetic effects to get the whole information,

which may not be needed?

. Ground fault interruptors are susceptible to EMI.

. Coordination of EMI efforts is needed.

. Everyone should carry the cost of implementing EMI solutions.

. Parts of systems fabricated and tested separately do not imply the total

system behavior can be predicted. We must have a system approach to these

problems with more understanding of the EMI phenomena. EMI phenomena are often non-linear in frequency.

. The only reason the voluntary standards program works is that people are afraid they are going to be regulated. (Paraphrase from R. M. Showers - U . of Penn.

)

. Conflicting EMI standards exist that are causing economic hardships and are barriers to trade.

The attendees also raised concern about legal and political matters. As

an example: In a situation where an EM source is interfering with

electronics equipment used for protection or control and owned by a different

party, who should be responsible and pay for the fix? In general, where does

the responsibility of users, owners, and manufacturers rest? Similarly, the

question can be raised: If we accept the thesis that regulation, at best, is

a weak attempt at an EMI solution and that regulation does not solve the

problem, then how can coordination be achieved in solving EMI problems with

consumer products or in any other arena? The complexity of the

electromagnetic interference problem pictured by the attendees is vast and

the system approach toward solutions seems to be the only viable attack that can work successfully. However, while this approach could be practical in

industrial, medical, and automotive applications, it could be very difficult

to apply in consumer electronic settings.

46
In retrospect, it was evident certain assumptions were tacitly agreed to

because of traditional outlooks that were present. For example,

communicators, whether representing the receiving or transmitting sides, concern themselves with mutual interference and they traditionally see themselves as having an a priori right to the airwaves; consequently, it is

difficult for this type of person to recognize the need to shift

communications to non-radiating methods of communication to reduce the

numbers of sources contributing to EM pollution in congested areas. This concern surfaced when one attendee raised the question why more attention was

not given to the amount of radiation that can be safely emitted. The FCC is

chartered with planning for EM compatibility and so has no jurisdiction in

assessing when an area or locality has enough radiation from a safety

perspective and, therefore, no further radiators should be permitted. Should

the charter of the FCC be changed in this respect? Should the rewrite of the

Communications Act plan for a "sunset" provision on all licensed radiators?

If state and local governments limit combined radiation levels, as was proposed by New York City, envision the complications this will create

legally, technically, and in measurement verification.

The single, most accordant theme that emerged from the workshop was that

EM environment measurements were needed and a Federal agency should be

chartered with this responsibility.

The EMI Workshop was not successful in attracting a significant

contingent of managers or decision makers. Apparently our publicity and

mailings did not reach the right audience. In this sense, it was not a complete success. Nevertheless, the interaction from the more than 200

attendees was generally quite favorable. The individual sessions had varying

degrees of success in achieving the workshop atmosphere where concerted

attendee interaction was achieved. The industrial session achieved a greater

degree of interaction than most.

It is not clear at this time that a third EMI workshop will be sponsored

by NBS. Questions of emphasis, usefulness, format, and timing are yet to be

resolved.

47
NBS-114A (REV. 9-781

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBS SP 551

2.00/1 Acfcesston Ho.

4. TITLE AND SUBTITLE PROCEEDINGS OF THE 1978 ELECTROMAGNETIC INTERFERENCE

WORKSHOP

5, Publication Date July 1979

; $. Perfomiifig Organization Code

7. AUTHOR{S) M. G. Arthur, Editor8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

10,, Project/Task/Work ifeit No.

11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS fstreet, city, si^ie. ziP) 13. Type of Report & Period Covered Final

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES Library of Congress Catalog Card Number: 79-600091

I I Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant bibliography or

literature survey, mention it here.) This report is a summary of the overview talks and session discussions at the 1978

Electromagnetic Interference Workshop, held at the National Bureau of Standards,

Gaithersburg, Maryland, on November 2 and 3, 1978. These discussions addressed the

following questions: What are the significant Electromagnetic Interference (EMI)

problems? How serious are they? Which should be tackled first? What solutions

are practical? Who is responsible for solutions? What new standards or changes

in present voluntary standards are needed? What is needed for progress? Impacted

areas featured at the workshop included communications, transportation, consumer

products, industrial, and medical. Workshop speakers and attendees represented a broad segment of decision-makers in both industry and government.

17. KEY WORDS ("six (o twelve entries: alphabetical order: capitalize only the first letter of the first key word unless a proper name;

separated by semicolons) Electromagnetic bioeffects; electromagnetic compatibility; electromagnetic immunity;

electromagnetic interference; electromagnetic radiation; electromagnetic susceptibility; electronic smog; home entertainment electronics; industrial electronics; medical electronics; microwave electronics; non- ionizing radiation; radiation hazards; radio regulations; radio standards; RFI; spectrum management;

standardization organizations; telecommunications; TV!-; vehicular electronics.

18. AVAILABILITY QUnlimited

I I For Official Distribution. Do Not Release to NTIS

\tc\ Order From Sup. of Doc, U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003-

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

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There's

anew

look

to.,.

. . . the monthly

magazine of the National Bureau of Standards.

Still featured are special articles of general interest on

current topics such as consumer product safety and building

technology. In addition, new sections are designed to . . . PROVIDE

SCIENTISTS with illustrated discussions

of recent technical developments and

work in progress . . . INFORM INDUSTRIAL

MANAGERS of technology transfer activities in Federal and private labs. . . DESCRIBE TO MANUFACTURERS advances in the field of voluntary and

mandatory standards. The new DIMENSiONS/NBS also

carries complete listings of upcoming conferences to be

held at NBS and reports on all the latest NBS publications,

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NBS TECHNICAL PUBLICATIONS

PERIODICALS

JOURNAL OF RESEARCH—The Journal of Research

of the National Bureau of Standards reports NBS research and development in those disciplines of the physical and

engineering sciences in which the Bureau is active. These

include physics, chemistry, engineering, mathematics, and

computer sciences. Papers cover a broad range of subjects, with major emphasis on measurement methodology, and

the basic technology underlying standardization. Also in- cluded from time to time are survey articles on topics closely

related to the Bureau's technical and scientific programs. As

a special service to subscribers each issue contains complete

citations to all recent NBS publications in NBS and non- NBS media. Issued six times a year. Annual subscription: domestic $17.00; foreign $21.25. Single copy, $3.00 domestic;

$3.75 foreign. Note: The Journal was formerly published in two sections: Section A "Physics and Chemistry" and Section B "Mathematical Sciences." DIMENSIONS/NBS

This monthly magazine is published to inform scientists, engineers, businessmen, industry, teachers, students, and

consumers of the latest advances in science and technology,

with primary emphasis on the work at NBS. The magazine

highlights and reviews such issues as energy research, fire protection, building technology, metric conversion, pollution

abatement, health and safety, and consumer product per- formance. In addition, it reports the results of Bureau pro- grams in measurement standards and techniques, properties

of matter and materials, engineering standards and services, instrumentation, and automatic data processing.

Annual subscription: Domestic, $11.00; Foreign $13.75

NONPERIODICALS

Monographs—Major contributions to the technical liter- ature on various subjects related to the Bureau's scientific and technical activities. Handbooks—Recommended codes of engineering and industrial practice (including safety codes) developed in cooperation with interested industries, professional organizations, and regulatory bodies.

Special Publications—Include proceedings of conferences sponsored by NBS, NBS annual reports, and other special

publications appropriate to this grouping such as wall charts, pocket cards, and bibliographies.

Applied Mathematics Series—Mathematical tables, manuals, and studies of special interest to physicists, engineers,

chemists, biologists, mathematicians, computer programmers,

and others engaged in scientific and technical work.

National Standard Reference Data Series—Provides quantitative data on the physical and chemical properties of

materials, compiled from the world's literature and critically evaluated. Developed under a world-wide program co- ordinated by NBS. Program under authority of National

Standard Data Act (Public Law 90-396).

NOTE: At present the principal publication outlet for these data is the Journal of Physical and Chemical Reference Data (JPCRD) published quarterly for NBS by the American Chemical Society (ACS) and the American Institute of

Physics (AIP). Subscriptions, reprints, and supplements

available from ACS, 1155 Sixteenth St. N.W., Wash., D.C.

20056.

Building Science Series—Disseminates technical information developed at the Bureau on building materials, components,

systems, and whole structures. The series presents research

results, test methods, and performance criteria related to the

structural and environmental functions and the durability and safety characteristics of building elements and systems. Technical Notes—Studies or reports which are complete in themselves but restrictive in their treatment of a subject.

Analogous to monographs but not so comprehensive in scope or definitive in treatment of the subject area. Often

serve as a vehicle for final reports of work performed at NBS under the sponsorship of other government agencies.

Voluntary Product Standards—Developed under procedures

published by the Department of Commerce in Part 10, Title 15, of the Code of Federal Regulations. The purpose

of the standards is to establish nationally recognized require- ments for products, and to provide all concerned interests with a basis for common understanding of the characteristics of the products. NBS administers this program as a supple- ment to the activities of the private sector standardizing

organizations.

Consumer Information Series—Practical information, based on NBS research and experience, covering areas of interest

to the consumer. Easily understandable language and

illustrations provide useful background knowledge for shopping in today's technological marketplace.

Order above NBS publications from: Superintendent of Documents, Government Printing Office, Washington, D.C.

20402. Order following NBS publications—NBSIR's and FIPS from

the National Technical Information Services, Springfield, Va. 22161.

Federal Information Processing Standards Publications (FIPS PUB)—Publications in this series collectively constitute the Federal Information Processing Standards Register.

Register serves as the official source of information in the Federal Government regarding standards issued by NBS

pursuant to the Federal Property and Administrative Services Act of 1949 as amended, Public Law 89-306 (79 Stat. 1127), and as implemented by Executive Order 11717

(38 FR 12315, dated May 11, 1973) and Part 6 of Title 15 CFR (Code of Federal Regulations).

NBS Interagency Reports (NBSIR)—A special series of

interim or final reports on work performed by NBS for outside sponsors (both government and non-government).

In general, initial distribution is handled by the sponsor;

public distribution is by the National Technical Information

Services (Springfield, Va. 22161) in paper copy or microfiche form.

BIBLIOGRAPHIC SUBSCRIPTION SERVICES

The following current-awareness and literature-survey bibli- ographies are issued periodically by the Bureau:

Cryogenic Data Center Current Awareness Service. A litera- ture survey issued biweekly. Annual subscription: Domestic, $25.00; Foreign, $30.00.

Liquefied Natural Gas. A literature survey issued quarterly.

Annual subscription: $20.00.

Superconducting Devices and Materials. A literature survey

issued quarterly. Annual subscription: $30.00. Send subscription orders and remittances for the preceding bibliographic

services to National Bureau of Standards, Cryogenic Data

Center (275.02) Boulder, Colorado 80302.
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