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Introduction Test Information Test Results


The Electromagnetic Radiation (EMR), Electromagnetic Field (EMF) and Radio Frequency (RF) radiation data available from multiple sources was thoroughly analyzed while developing and before testing the first commercially available AegisGuard™ products, AegisGuard™ Phone Radiation Shields (superseded by AegisGuard™ LS Radiation Shields in 2005).

It has always been known that radiation emitted by wireless products penetrate the body of the user when the products are in use. In recent years, it has also been confirmed that radiation penetration occurs when using wired products, and concerns expressed about the health effects at very low wireless product frequencies have been substantiated. The effects of the radiation and standards used to measure the effects upon the human body are still being debated by scientists, engineers and those in the medical profession.

It became evident early in the product development phase that SAR (Specific Absorption Rate) test procedures developed by the United States Air Force, and are used by regulatory agencies worldwide as the criteria for wireless product and network and safety phone safety,  were inadequate for determining if there were heath risks for a number of very important reasons (see SAR Overview for additional information).

  • SAR standards were not designed to measure cumulative effects upon the body and there has never been a study stating that wireless products meeting these standards are safe.
  • SAR standards are theoretically acceptable human body radiation absorption rate simulations that measure non-ionizing radiation temperatures (thermal), rather than actual near field radiation emissions measured in decibels (dB). The existing SAR standards were created by the United States Air Force after exposing a healthy 28 year old male to a sunny, hot, humid environment for 61 minutes, measuring his temperature rectally, and calculating estimated safe thermal thresholds for individual body organs. Decibel measurements are used for testing every other aspect of wireless communications as well as all AegisGuard™ products, and despite numerous studies confirming that cellular phone radiation far below the thermal level is harmful to human health, the SAR standard continues to be used. It is also very important to understand that none of the health effects attributed to non-ionizing radiation are thermally induced. 
  • For wireless phones, SAR tests measure thermal emissions primarily from the speaker when placed against the ear of a plastic model head for a brief amount of time, typically less than 15 minutes. The outside of the model's ear has a rubber disc so that a phone can be positioned against it and the thickness of the disc varies, which affects the test results. Almost all of a wireless phone's radiation is generated by the radio system (transmitter and receiver), which in newer phone models is located away from the earpiece near the display or keypad. This significantly affects SAR test results, particularly for full flip-style phones where the entire radio system is located in the lower half of the phone.
  • SAR test data presented by most personal radiation shielding product manufacturers do not include test time, multiple frequencies, test results above 1 GHz., or output power levels, all of which are important considerations. Of the few that provide this type of information, a close examination of the information provided reveals the frequencies tested were below 1 GHz., which is much lower than the frequency used by most wireless phones currently available, and the duration of the test, if presented at all, is 15 seconds or less. The duration of each product or environmental AegisGuard™ Radiation Shield test was at least 8 hours.

Rather than 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.

During the 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.

Although the 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 AegisGuard™ Life 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. Click here for additional information about these tests.


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