Table 1.10 Dielectric Constants of Solids in the Temperature Range 17–22°C (From [1].
Used with permission.)
© 2000 by CRC PRESS LLC
Whitaker, Jerry C. “International Standards and Constants”
The Resource Handbook of Electronics.
Ed. Jerry C. Whitaker
Boca Raton: CRC Press LLC, ©2001
© 2001 by CRC PRESS LLC
Chapter
2
International Standards and
Constants
2.1 Introduction
Standardization usually starts within a company as a way to reduce costs associated
with parts stocking, design drawings, training, and retraining of personnel. The next
level might be a cooperative agreement between firms making similar equipment to
use standardized dimensions, parts, and components. Competition, trade secrets, and
the NIH factor (not invented here) often generate an atmosphere that prevents such an
understanding. Enter the professional engineering society, which promises a forum
for discussion between users and engineers while downplaying the commercial and
business aspects.
2.2 The History of Modern Standards
In 1836, the U.S. Congress authorized the Office of Weights and Measures (OWM)
for the primary purpose of ensuring uniformity in custom house dealings. The Trea-
sury Department was charged with its operation. As advancements in science and
technology fueled the industrial revolution, it was apparent that standardization of
hardware and test methods was necessary to promote commercial development and to
compete successfully with the rest of the world. The industrial revolution in the 1830s
introduced the need for interchangeable parts and hardware. Economical manufacture
of transportation equipment, tools, weapons, and other machinery was possible only
with mechanical standardization.
By the late 1800s professional organizations of mechanical, electrical, chemical,
and other engineers were founded with this aim in mind. The Institute of Electrical En-
gineers developed standards between 1890 and 1910 based on the practices of the ma-
jor electrical manufacturers of the time. Such activities were not within the purview of
the OWM, so there was no government involvement during this period. It took the pres-
sures of war production in 1918 to cause the formation of the American Engineering
© 2001 by CRC PRESS LLC
Standards Committee (AESC) to coordinate the activities of various industry and engi-
neering societies. This group became the American Standards Association (ASA) in
1928.
Parallel developments would occur worldwide. The International Bureau of
Weights and Measures was founded in 1875, the International Electrotechnical Com-
mission (IEC) in 1904, and the International Federation of Standardizing Bodies (ISA)
in 1926. Following World War II (1946) this group was reorganized as the International
Standards Organization (ISO) comprised of the ASA and the standardizing bodies of
25 other countries. Present participation is approximately 55 countries and 145 techni-
cal committees. The stated mission of the ISO is to facilitate the internationalization
and unification of industrial standards.
The International Telecommunications Union (ITU) was founded in 1865 for the
purpose of coordinating and interfacing telegraphic communications worldwide. To-
day, its member countries develop regulations and voluntary recommendations, and
provide coordination of telecommunications development. A sub-group, the Interna-
tional Radio Consultative Committee (CCIR) (which no longer exists under this name),
is concerned with certain transmission standards and the compatible use of the fre-
quency spectrum, including geostationary satellite orbit assignments. Standardized
transmission formats to allow interchange of communications over national bound-
aries are the purview of this committee. Because these standards involve international
treaties, negotiations are channeled through the U.S. State Department.
2.2.1 American National Standards Institute (ANSI)
ANSI coordinates policies to promote procedures, guidelines, and the consistency of
standards development. Due process procedures ensure that participation is open to
all persons who are materially affected by the activities without domination by a par-
ticular group. Written procedures are available to ensure that consistent methods are
used for standards developments and appeals. Today, there are more than 1000 mem-
bers who support the U.S. voluntary standardization system as members of the ANSI
federation. This support keeps the Institute financially sound and the system free of
government control.
The functions of ANSI include: (1) serving as a clearinghouse on standards devel-
opment and supplying standards-related publications and information, and (2) the fol-
lowing business development issues:
• Provides national and international standards information necessary to market
products worldwide.
• Offers American National Standards that assist companies in reducing operating
and purchasing costs, thereby assuring product quality and safety.
• Offers an opportunity to voice opinion through representation on numerous tech-
nical advisory groups, councils, and boards.
• Furnishes national and international recognition of standards for credibility and
force in domestic commerce and world trade.
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• Provides a path to influence and comment on the development of standards in the
international arena.
Prospective standards must be submitted by an ANSI accredited standards devel-
oper. There are three methods which may be used:
• Accredited organization method. This approach is most often used by associa-
tions and societies having an interest in developing standards. Participation is
open to all interested parties as well as members of the association or society. The
standards developer must fashion its own operating procedures, which must meet
the general requirements of the ANSI procedures.
• Accredited standards committee method. Standing committees of directly and
materially affected interests develop documents and establish consensus in sup-
port of the document. This method is most often used when a standard affects a
broad range of diverse interests or where multiple associations or societies with
similar interests exist. These committees are administered by a secretariat, an or-
ganization that assumes the responsibility for providing compliance with the per-
tinent operating procedures. The committee can develop its own operating proce-
dures consistent with ANSI requirements, or it can adopt standard ANSI proce-
dures.
• Accredited canvass method. This approach is used by smaller trade associations
or societies that have documented current industry practices and desire that these
standards be recognized nationally. Generally, these developers are responsible
for less than five standards. The developer identifies those who are directly and
materially affected by the activity in question and conducts a letter ballot canvass
of those interests to determine consensus. Developers must use standard ANSI
procedures.
Note that all methods must fulfill the basic requirements of public review, voting,
consideration, and disposition of all views and objections, and an appeals mechanism.
The introduction of new technologies or changes in the direction of industry groups
or engineering societies may require a mediating body to assign responsibility for a de-
veloping standard to the proper group. The Joint Committee for Intersociety Coordina-
tion (JCIC) operates under ANSI to fulfill this need.
2.2.2 Professional Society Engineering Committees
The engineering groups that collate and coordinate activities that are eventually pre-
sented to standardization bodies encourage participation from all concerned parties.
Meetings are often scheduled in connection with technical conferences to promote
greater participation. Other necessary meetings are usually scheduled in geographical
locations of the greatest activity in the field. There are no charges or dues to be a
member or to attend the meetings. An interest in these activities can still be served by
reading the reports from these groups in the appropriate professional journals. These
© 2001 by CRC PRESS LLC
wheels may seem to grind exceedingly slowly at times, but the adoption of standards
that may have to endure for 50 years or more should not be taken lightly.
2.3 References
1. Whitaker, Jerry C. (ed.), The Electronics Handbook, CRC Press, Boca Raton, FL,
1996.
2.4 Bibliography
Whitaker, Jerry C., and K. Blair Benson (eds.), Standard Handbook of Video and Tele-
vision Engineering, McGraw-Hill, New York, NY, 2000.
2.5 Tabular Data
Table 2.1 Common Standard Units
Name Symbol Quantity
ampere A electric current
ampere per meter A/m magnetic field strength
2
ampere per square meter A/m current density
becquerel Bg activity (of a radionuclide)
candela cd luminous intensity
coulomb C electric charge
coulomb per kilogram C/kg exposure (x and gamma rays)
2
coulomb per sq. meter C/m electric flux density
3
cubic meter m volume
3
cubic meter per kilogram m /kg specific volume
degree Celsius °C Celsius temperature
farad F capacitance
farad per meter F/m permittivity
henry H inductance
henry per meter H/m permeability
hertz Hz frequency
joule J energy, work, quantity of heat
3
joule per cubic meter J/m energy density
joule per kelvin J/K heat capacity
joule per kilogram K J/(kg•K) specific heat capacity
joule per mole J/mol molar energy
kelvin K thermodynamic temperature
kilogram kg mass
3
kilogram per cubic meter kg/m density, mass density
lumen lm luminous flux
lux lx luminance
© 2001 by CRC PRESS LLC
Table 2.1 Common Standard Units (continued)
Name Symbol Quantity
meter m length
meter per second m/s speed, velocity
2
meter per second sq. m/s acceleration
mole mol amount of substance
newton N force
newton per meter N/m surface tension
ohm Ω electrical resistance
pascal Pa pressure, stress
pascal second Pa•s dynamic viscosity
radian rad plane angle
radian per second rad/s angular velocity
2
radian per second squared rad/s angular acceleration
second s time
siemens S electrical conductance
2
square meter m area
steradian sr solid angle
tesla T magnetic flux density
volt V electrical potential
volt per meter V/m electric field strength
watt W power, radiant flux
watt per meter kelvin W/(m•K) thermal conductivity
2
watt per square meter W/m heat (power) flux density
weber Wb magnetic flux
Table 2.2 Standard Prefixes
Multiple Prefix Symbol
18
10 exa E
15
10 peta P
12
10 tera T
9
10 giga G
6
10 mega M
3
10 kilo k
2
10 hecto h
10 deka da
-1
10 deci d
-2
10 centi c
-3
10 milli m
-6
10 micro µ
-9
10 nano n
-12
10 pico p
-15
10 femto f
-18
10 atto a
© 2001 by CRC PRESS LLC
Table 2.3 Common Standard Units for Electrical Work
Unit Symbol
centimeter cm
3
cubic centimeter cm
3
cubic meter per second m /s
gigahertz GHz
gram g
kilohertz kHz
kilohm kΩ
kilojoule kJ
kilometer km
kilovolt kV
kilovoltampere kVA
kilowatt kW
megahertz MHz
megavolt MV
megawatt MW
megohm MΩ
microampere µA
microfarad µF
microgram µg
microhenry µH
microsecond µs
microwatt µW
milliampere mA
milligram mg
millihenry mH
millimeter mm
millisecond ms
millivolt mV
milliwatt mW
nanoampere nA
nanofarad nF
nanometer nm
nanosecond ns
nanowatt nW
picoampere pA
picofarad pF
picosecond ps
picowatt pW
© 2001 by CRC PRESS LLC
© 2001 by CRC PRESS LLC
Table 2.4 Names and Symbols for the SI Base Units (From [1]. Used Used with permission.)
© 2001 by CRC PRESS LLC
Table 2.5 Units in Use Together with the SI (These units are not part of the SI, but it is recognized that
they will continue to be used in appropriate contexts. From [1]. Used with permission.)
© 2001 by CRC PRESS LLC
Table 2.6 Derived Units with Special Names and Symbols (From [1]. Used with permission.)
© 2001 by CRC PRESS LLC
Table 2.7 The Greek Alphabet (From [1]. Used with permission.)
Table 2.8 Constants (From [1]. Used with permission.)
© 2001 by CRC PRESS LLC
Whitaker, Jerry C. “Electromagnetic Spectrum”
The Resource Handbook of Electronics.
Ed. Jerry C. Whitaker
Boca Raton: CRC Press LLC, ©2001
© 2001 by CRC PRESS LLC
Chapter
3
Electromagnetic Spectrum
3.1 Introduction
The usable spectrum of electromagnetic-radiation frequencies extends over a range
from below 100 Hz for power distribution to 1020 for the shortest X-rays. The lower
frequencies are used primarily for terrestrial broadcasting and communications. The
higher frequencies include visible and near-visible infrared and ultraviolet light, and
X-rays.
3.1.1 Operating Frequency Bands
The standard frequency band designations are listed in Tables 3.1 and 3.2. Alternate
and more detailed subdivision of the VHF, UHF, SHF, and EHF bands are given in Ta-
bles 3.3 and 3.4.
Low-End Spectrum Frequencies (1 to 1000 Hz)
Electric power is transmitted by wire but not by radiation at 50 and 60 Hz, and in
some limited areas, at 25 Hz. Aircraft use 400-Hz power in order to reduce the weight
of iron in generators and transformers. The restricted bandwidth that would be avail-
able for communication channels is generally inadequate for voice or data transmis-
sion, although some use has been made of communication over power distribution cir-
cuits using modulated carrier frequencies.
Low-End Radio Frequencies (1000 to 100 kHz)
These low frequencies are used for very long distance radio-telegraphic communica-
tion where extreme reliability is required and where high-power and long antennas
can be erected. The primary bands of interest for radio communications are given in
Table 3.5.
© 2001 by CRC PRESS LLC
Table 3.1 Standardized Frequency Bands (From [1]. Used with permission.)
Table 3.2 Standardized Frequency Bands at 1GHz and Above (From [1]. Used with per-
mission.)
Medium-Frequency Radio (20 kHz to 2 MHz)
The low-frequency portion of the band is used for around-the-clock communication
services over moderately long distances and where adequate power is available to
overcome the high level of atmospheric noise. The upper portion is used for AM ra-
dio, although the strong and quite variable sky wave occurring during the night results
in substandard quality and severe fading at times. The greatest use is for AM broad-
casting, in addition to fixed and mobile service, LORAN ship and aircraft navigation,
and amateur radio communication.
High-Frequency Radio (2 to 30 MHz)
This band provides reliable medium-range coverage during daylight and, when the
transmission path is in total darkness, worldwide long-distance service, although the
© 2001 by CRC PRESS LLC
Table 3.3 Detailed Subdivision of the UHF, SHF, and EHF Bands (From [1]. Used with
permission.)
Table 3.4 Subdivision of the VHF, UHF, SHF Lower Part of the EHF Band (From [1].
Used with permission.)
reliability and signal quality of the latter is dependent to a large degree upon iono-
spheric conditions and related long-term variations in sun-spot activity affecting
sky-wave propagation. The primary applications include broadcasting, fixed and mo-
bile services, telemetering, and amateur transmissions.
© 2001 by CRC PRESS LLC
Table 3.5 Radio Frequency Bands (From [1]. Used with permission.)
Very High and Ultrahigh Frequencies (30 MHz to 3 GHz)
VHF and UHF bands, because of the greater channel bandwidth possible, can provide
transmission of a large amount of information, either as television detail or data com-
munication. Furthermore, the shorter wavelengths permit the use of highly directional
parabolic or multielement antennas. Reliable long-distance communication is pro-
vided using high-power tropospheric scatter techniques. The multitude of uses in-
clude, in addition to television, fixed and mobile communication services, amateur
radio, radio astronomy, satellite communication, telemetering, and radar.
Microwaves (3 to 300 GHz)
At these frequencies, many transmission characteristics are similar to those used for
shorter optical waves, which limit the distances covered to line of sight. Typical uses
include television relay, satellite, radar, and wide-band information services. (See Ta-
bles 3.6 and 3.7.)
Infrared, Visible, and Ultraviolet Light
The portion of the spectrum visible to the eye covers the gamut of transmitted colors
ranging from red, through yellow, green, cyan, and blue. It is bracketed by infrared on
the low-frequency side and ultraviolet (UV) on the high side. Infrared signals are used
in a variety of consumer and industrial equipments for remote controls and sensor cir-
cuits in security systems. The most common use of UV waves is for excitation of
phosphors to produce visible illumination.
X-Rays
Medical and biological examination techniques and industrial and security inspection
systems are the best-known applications of X-rays. X-rays in the higher-frequency
range are classified as hard X-rays or gamma rays. Exposure to X-rays for long peri-
ods can result in serious irreversible damage to living cells or organisms.
© 2001 by CRC PRESS LLC
Table 3.6 Applications in the Microwave Bands (From [1]. Used with permission.)
© 2001 by CRC PRESS LLC
Table 3.6 Applications in the Microwave Bands (continued)
3.2 Radio Wave Propagation
To visualize a radio wave, consider the image of a sine wave being traced across the
screen of an oscilloscope [2]. As the image is traced, it sweeps across the screen at a
specified rate, constantly changing amplitude and phase with relation to its starting
point at the left side of the screen. Consider the left side of the screen to be the an-
tenna, the horizontal axis to be distance instead of time, and the sweep speed to be the
speed of light, or at least very close to the speed of light, and the propagation of the ra-
dio wave is visualized. To be correct, the traveling, or propagating, radio wave is re-
ally a wavefront, as it comprises an electric field component and an orthogonal mag-
netic field component. The distance between wave crests is defined as the wavelength
and is calculated by,
c
λ= (3.1)
f
where:
λ = wavelength, m
c = the speed of light, approximately 2.998 × 10 m/s
8
f = frequency, Hz
At any point in space far away from the antenna, on the order of 10 wavelengths or 10
times the aperture of the antenna to avoid near-field effects, the electric and magnetic
fields will be orthogonal and remain constant in amplitude and phase in relation to any
other point in space. The polarization of the radio wave is defined by the polarization of
the electric field, horizontal if parallel to the Earth’s surface and vertical if perpendicu-
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