Filter
Top Products
Section 4: Safety Guidelines and Warranty Information
4A: Safety 107
one wave per second. One kilohertz (kHz) equals one thousand waves per
second, one megahertz (MHz) equals one million waves per second, and
one gigahertz (GHz) equals one billion waves per second.
RF energy includes waves with frequencies ranging from about 3000
waves per second (3 kHz) to 300 billion waves per second (300 GHz).
Microwaves are a subset of radio waves that have frequencies ranging
from around 300 million waves per second (300 MHz) to three billion
waves per second (3 GHz).
2. How is radio frequency energy used?
Probably the most important use of RF energy is for
telecommunications. Radio and TV broadcasting, wireless phones,
pagers, cordless phones, police and fire department radios, point-to-point
links and satellite communications all rely on RF energy.
Other uses of RF energy include microwave ovens, radar, industrial
heaters and sealers, and medical treatments. RF energy, especially at
microwave frequencies, can heat water. Since most food has a high water
content, microwaves can cook food quickly. Radar relies on RF energy to
track cars and airplanes as well as for military applications. Industrial
heaters and sealers use RF energy to mold plastic materials, glue wood
products, seal leather items such as shoes and pocketbooks, and process
food. Medical uses of RF energy include pacemaker monitoring and
programming.
3. How is radio frequency radiation measured?
RF waves and RF fields have both electrical and magnetic components. It
is often convenient to express the strength of the RF field in terms of each
component. For example, the unit "volts per meter" (V/m) is used to
measure the electric field strength, and the unit "amperes per meter" (A/
m) is used to express the magnetic field strength. Another common way
to characterize an RF field is by means of the power density. Power
density is defined as power per unit area. For example, power density can
be expressed in terms of milliwatts (one thousandth of a watt) per square
centimeter (mW/cm2 or microwatts (one millionth of a watt) per square
centimeter (µW/cm2).
The quantity used to measure how much RF energy is actually absorbed
by the body is called the Specific Absorption Rate or SAR. The SAR is a
Sprint FM OUG NO BROWSER CTIA-3a.book Page 107 Wednesday, October 9, 2002 1:42 PM