Just a few short words about the difference between EMF and MF
Magnetic fields
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Magnetic fields arise from current flows and will vary with the power consumtion.
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Magnetic fields exist as soon as a device is switched on and current flows.
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The field strength will decrease with distance from the source.
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The strength of a magnetic field is measured in amperes per meter (A/m). Most EMF investigators use flux density (in microtesla (µT) or millitesla (mT) instead.
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Most materials do not shield magnetic fields.
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The Earth's magnetic field is an example of a natural accuring magnetic field.
Electric fields
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Electric fields arise from the voltage itself.
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Electric fields stay constant.
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An electric field can be present even when a device is switched off. for example a table lamp plugged in but turned off will still have a electric field.
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The field strength will decrease with distance from the source.
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Their strength is measured in Volts per metre (V/m)
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Most building materials and trees shield electric fields to some extent.
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The local build-up of electrical charges in the atmosphere associated with thunderstorms is an example of natural accuring electric fields.