User's Manual

Safety
19
= +E
tot1
2
E
tot2
2
E
toti
2
E
totn
2
+ +E
totN
In the specific case of broadcasting plants for sound and television broadcasting, the fol-
lowing recurrent characteristics can be found:
a. the source is not isotropic, so the ERP should be calculated in the direction of the evalua-
tion point
b. in the case in which the worst case of exposure is concerned, it can be applied the
expression 2 in which the maximum transmitted ERP power is considered, regardless
of the direction, ignoring the radiation characteristics of the antenna system in the hori-
zontal and vertical plane
c. the polarization of the field is almost always vertical in the case of systems for sound
broadcasting, while it can be vertical, horizontal or mixed in the case of television broad-
casting. In all cases, the decomposition of the power transmitted in the various polariza-
tion components and the subsequent recombination by means of formula 3 allows,
firstly, to disregard the polarization of the field and to directly apply the expression 2
d. in the case of multiple sources, the total expression
4.
The following table gives an indication of the first approximation of the field value as a func-
tion of the power (in W) transmitted by the source and distance (in meters); the values
shown (all in V/m) represent the worst case (see point)