presenting calculated, estimated or simulated results and comparing them
against contested SAR thermal specifications, all AegisGuard™ Radiation
Shield tests were conducted by three independent laboratories measuring
the actual radiation frequencies with AegisGuard™ Radiation Shields installed,
and presented the result for each test in decibels (dB), which is the
global standard unit of measurement used to determine the
absolute ratio, or comparison, of voltage, power, gain, loss, and
frequency signal levels.
In 1998, globally
accepted test procedures developed by the American Society of Test and
Measurement (ASTM D4935-99) were used, and custom shields were also made
for radio modems to test the shielding effectiveness frequencies up to 2.6
GHz, which was higher than
any wireless phone available at the time. The same procedures were used to
test AegisGuard™ Wired Headset, (Life) Series and XP Radiation Shields at frequencies up to 2.6 GHz.
design phase of AegisGuard™ Life Series and XP Radiation Shields, it was
understood that ASTM
D4935-99 procedures could not be used for testing shielding effectiveness above 2.6 GHz. because
they were not designed to do so. A procedure that might have been used was
a military test standard (MIL-STD-285), but it was designed for testing large enclosures and
its use has declined since 1997.
On June 25,
1956, the United States Department of Defense (DoD) approved the use of
attenuation testing measurement standards and procedures designated as
MIL-STD-285 for the electromagnetic shielding of building entrances, doors
and large electronic equipment access panels. DoD formally discontinued
using this standard
on October 24, 1997 after the responsibility for developing and maintaining a
new standard was given to the IEEE. MIL-STD-285, however, continues to be
used by many testing laboratories.
frequency range of the new standard, designated IEEE-STD-299, is suitable
for testing AegisGuard™ L Series and XP Radiation Shields, the procedures were not
designed for testing products where the minimum dimension of any side of
an enclosure is less than 2 meters (78 inches).
Procedures for higher frequencies were developed in-house to
measure the shielding effectiveness of
Series and XP Radiation
Shields with the same type of test equipment used by
electronic product manufacturers, including wireless phones manufacturers and
carriers, and the same procedures were used to test
AegisGuard™ L Series Radiation
Shields. The results using these procedures are also presented in dB,
which is the same measurement used by manufacturers and carriers for
testing, and the
shielding effectiveness exceeds the requirements specified by MIL-STD-285, IEEE 299
and Human RF exposure limits as set forth in FCC OET Bulletin 65.
here for additional information about these