What is RF Radiation? – A Short Primer
In today’s connected world, almost everyone knows the term “RF”, but few know much about it. So, let’s take a quick dip into health physics for some essential knowledge.
Radiofrequency (RF) and microwave (MW) radiation are electromagnetic radiation in the frequency range 3 kilohertz (kHz) to 300 gigahertz (GHz). Usually MW radiation is considered a subset of RF radiation, although some treat RF and MW radiation as two spectral regions. Microwaves occupy the spectral region between 300 GHz and 300 MHz, while RF or radio waves include 300 MHz to 3 kHz.
RF/MW radiation are non-ionizing in that there is insufficient energy (less than 10 eV) to ionize biologically important atoms. The primary health effects of RF/MW energy are considered to be thermal. The absorption of RF/MW energy varies with frequency. Microwave frequencies produce a skin effect — you can literally sense your skin starting to feel warm. RF radiation may penetrate the body and be absorbed in deep body organs without the skin effect, which can warn an individual of danger. A great deal of research has not turned up significant non-thermal effects, but research continues. All the standards of western countries have, so far, based their exposure limits solely on preventing thermal problems.
Use of RF/MW radiation includes: Radio and TV broadcasting, WiFi, smartphones, cellular phones, processing and cooking of foods, heat sealers, vinyl welders, high frequency welders, induction heaters, flow solder machines, communications transmitters, radar transmitters, ion implant equipment, microwave drying equipment, sputtering equipment, glue curing, and power amplifiers used in EMC and metrology.
Maximum permissible exposure (MPE) levels are set in the US by standards bodies like the IEEE and ANSI, and enforced with respect to transmitting devices by the Federal Communications Commission, and for the workplace, OSHA. MPE’s are set to be quite conservative. The margin of safety for public exposure is 50 times less than any known hazards!
LBA offers an economical on-line certificate in RF Awareness that is widely used in the wireless workplace. You can access the training at https://www.lbagroup.com/associates/rftraining.php.