BS EN 50475:2008 – Basic standard for the calculation and the measurement of human exposure to electromagnetic fields from broadcasting service transmitters in the HF bands (3 MHz – 30 MHz)

1 Scope
This standard applies to short wave broadcast transmitters and installations operating in the frequency range 3 MHz to 30 MHz.
The objective of the standard is to specify, for such a frequency band, basic information allowing the definition of a method for assessment of compliance related to human exposure to radio frequency electromagnetic fields.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 5041 3, Basic standard on measurement and calculation procedures for human exposure to electric, magnetic and electromagnetic fields (0 Hz – 300 GHz)
EN 5501 6 series, Specification for radio disturbance and immunity measuring apparatus and methods (CISPR 1 6 series)
ENV 1 3005:1 999, Guide to the expression of uncertainty in measurement
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
action values
the magnitude of directly measurable parameters, provided in terms of electric field strength (E),magnetic field strength (H), magnetic flux density (B) and power density (S), at which one or more of the specified measures in 2004/40/EC [2] must be undertaken. Compliance with these values will ensure compliance with the relevant exposure limit values of 2004/40/EC [2]
3.2
antenna
device that serves as a transducer between a guided wave (e.g. coaxial cable) and a free space wave,or vice versa
3.3
basic restriction
restrictions on exposure to time-varying electric, magnetic, and electromagnetic fields that are based directly on established health effects as given in 1 999/51 9/EC [1 ]
3.4
broadcasting service
radio communication service in which the transmissions are intended for direct reception by the general public. This service may include sound transmissions, television transmissions or other typesof transmission
3.5
compliance distance
minimum distance from the antenna to a point of investigation where field level is deemed to be compliant to the limits
3.6
compliance boundary
surface around the antenna outside of which all field levels are deemed to be compliant to the limits
3.7
contact current (IC)
contact current between a person and an object exposed to the field, is expressed in amperes (A).
A conductive object in an electric field can be charged by the field
3.8
current density (J)
current density is defined as the current flowing through a unit cross section perpendicular to its direction in a volume conductor such as the human body or part of it, expressed in amperes per square meter (A/m²)
3.9
electric field strength (E)
magnitude of a field vector at a point that represents the force (F) on a positive small charge (q) divided by the charge
BS EN 50475:2008 – Basic standard for the calculation and the measurement of human exposure to electromagnetic fields from broadcasting service transmitters in the HF bands (3 MHz – 30 MHz)