What are Electric and Magnetic Fields? April 6, 2007Posted by healthyself in Blogroll, Definitions, Earth, Electrical Components, Electrical Pulses, Electrical Surges, Electrical Wiring, electromagnetic, Electromagnetic Field, Electromagnetic Radiation, Electromagnetic waves, EMF's, EMR, Environment, Frequencies, High Frequencies, high voltage transmission lines, Hz, LF, Light, light beam, Low Frequencies, Magnetic, MCS, MF, MHz, Microwave exposure, Pulsed Radiation, Pulses, Radar, Radians, radiation, Radio Frequency Radiation, Radio Waves, Resonant Frequency, Safe Levels, Transducer, transmission, UHF, VDT, VLF, W/Kg, W/m2, watts, Wave Front, Waves.
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High Frequency Electromagnetic Fields April 5, 2007Posted by healthyself in Amplified Signals, Amplitude, Antennas, Blogroll, Cable, Cell Masts, Cell phone industry, Cell phone safety, Cell Phones, Computer Rooms, Cordless Phones, Definitions, Digital, Distribution, Electrical Components, Electrical Pulses, Electrical Wiring, Electromagnetic Communications, Electromagnetic Field, Electromagnetic Interference, Electromagnetic pollution, Electromagnetic Radiation, Electromagnetic Spectrum, Electromagnetic waves, Electrosensitivity, Electrosmog, ELF, Emergency Medicine, EMF Research, EMF's, EMR, Energy, Environment, Epidemiology, Exposure, Frequencies, GHz, Government's role, HF, High Frequencies, high voltage transmission lines, Homes, HOuseholds, HRD, Human Resources, Hz, Infrared, Interdisciplinary, Landline, Laptops, Legal Issues, Lifestyle, Low Frequencies, MCS, MF, MHz, Microwave exposure, Mitigation, mobile telephones, Oscillate, Pulsed Radiation, Pulses, Radar, radiation, Radio Frequency Radiation, Radio Waves, Radios, Research Needed, Resonant Frequency, Risk of Disease, Sound, Speakerphones, Telecommunications, Telephony, Transducer, Transfer, transmission, UHF, VDT, VLF, W/Kg, W/m2, watts, Wave Front, Waves, Who is Affected?, WiFi, Wired, Wired Phone, Wireless, Wireless Phones, Workplace, X-Rays.
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“Mobile telephones, television and radio transmitters and radar produce RF fields. These fields are used to transmit information over long distances and form the basis of telecommunications as well as radio and television broadcasting all over the world. Microwaves are RF fields at high frequencies in the GHz range. In microwaves ovens, we use them to quickly heat food.””At radio frequencies, electric and magnetic fields are closely interrelated and we typically measure their levels as power densities in watts per square metre (W/m2).”
- The electromagnetic spectrum encompasses both natural and human-made sources of electromagnetic fields.
- Frequency and wavelength characterise an electromagnetic field. In an electromagnetic wave, these two characteristics are directly related to each other: the higher the frequency the shorter the wavelength.
- Ionizing radiation such as X-ray and gamma-rays consists of photons which carry sufficient energy to break molecular bonds. Photons of electromagnetic waves at power and radio frequencies have much lower energy that do not have this ability.
- Electric fields exist whenever charge is present and are measured in volts per metre (V/m). Magnetic fields arise from current flow. Their flux densities are measured in microtesla (µT) or millitesla (mT).
- At radio and microwave frequencies, electric and magnetic fields are considered together as the two components of an electromagnetic wave. Power density, measured in watts per square metre (W/m2), describes the intensity of these fields.
- Low frequency and high frequency electromagnetic waves affect the human body in different ways.
- Electrical power supplies and appliances are the most common sources of low frequency electric and magnetic fields in our living environment. Everyday sources of radiofrequency electromagnetic fields are telecommunications, broadcasting antennas and microwave ovens.”
What are Electromagnetic Fields? October 31, 2006Posted by healthyself in Definitions, Electromagnetic Communications, Electromagnetic Field, Electromagnetic pollution, Electromagnetic Radiation, Electrosmog, Frequencies.
What are ELF electromagnetic fields generated by power lines, wiring and appliances?
“All electric flows have an associated electric field and magnetic field. Both electric and magnetic fields are essentially ‘invisible lines of force’, each associated with a different characteristic of electricity. An electric field is the force created by the attraction and repulsion of electric charges (the cause of electric flow), and is measured in volts per meter (V/m). A magnetic field is a force created as a consequence of the movement of the charges (flow of electricity). The magnitude (intensity) of a magnetic field is usually measured in tesla (T) or sometimes in gauss (G). The intensity of both electric and magnetic fields decreases with distance from the field source. Electric fields are more easily shielded or blocked than magnetic fields.
Both electric and magnetic fields can vary in time. Whereas, direct current (DC) fields have a steady direction, flow rate and strength, alternating current (AC) fields change direction, flow rate and strength over time with a certain frequency.
Most electricity carried in powerlines, wiring and appliances is alternating current (AC). Worldwide, alternating current (AC) moves back and forth (cycles) either 50 or 60 times per second (the latter predominantly in US), that is, at a frequency of 50Hz and 60Hz respectively. Such electromagnetic fields are classified as Extremely Low Frequency (ELF) fields, as their frequency is within the range of 3 to 3000 Hz.”
“Electromagnetic fields produced by sources other than electricity, such as cellular phone antennas, have higher frequencies and are therefore not classified as Extremely Low Frequency (ELF) fields…”
Oscillation and Velocity October 22, 2006Posted by healthyself in 1 Hz, Blogroll, Definitions, Electrical Components, Electrical Pulses, electromagnetic, Electromagnetic Field, Electromagnetic Radiation, Electromagnetic waves, EMF Research, EMF's, Frequencies, Oscillate, Pulsed Radiation, Pulses, radiation, Waves.
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“Electromagnetic radiation results from oscillations of components of electric and magnetic fields. In the simplest cases, these oscillations occur with definite frequency (the unit of frequency measurement is 1 Hertz (Hz), which is one oscillation per second). Arising in some point (under the action of the radiation source), electromagnetic radiation travels with the velocity that is equal to the velocity of the light, and this velocity is equal for all frequencies. Another quantity, wavelength, is often used for the description of electromagnetic radiation (this quantity is similar to the distance between two neighbor crests of waves spreading on a water surface, which appear after dropping a stone on the surface). Because the product of the wavelength and frequency must equal the velocity of light, the greater the wave frequency, the less its wavelength.”