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Part of the Confusion is the Vast Difference Between Standards
Notice that when you are reading RADIO/MICROWAVE measurements and comparing them
to the various standards you want to follow, you will need to double check to make sure the
units it is expressed in. Sometimes the units of the allowable safety standard and the
biological standard are so vastly different that we need to change the units of scale so that we
do not use an entire page of paper including the zeros. So, watch for switches from meters
squared to centimeters squared, watts and milliwatts. Example: 10 W/m
2
= 1mW/cm
2
, or,
0.1 W/m
2
= 0.01mW/cm
2
.
Why we Measure in Power Density units and not Field Strength units?
In today’s world, Power flux density is the measurement by which a wide variety of existing
safety standards are defined. With regards to
today’s
conventional EMF safety standards this
refers to the amount of power required to produce a tissue heating effect in the body.
An important distinction of radio/microwave meters is that they most often do not measure
field strength (the level of EMF exposure, which relates to how strong an effect it is capable of
exerting on biological systems, such as voltage-gated cell membranes), rather they measure
power density of the field (tissue heating effects).
It is anticipated that in the future, the standard will be changed to field strength (measured
in volts per meter) since that will relate to a wider range of biological effects than merely
heating. Meantime, conversion charts, which you will find in Part IV, enable us to convert
from p
ower density to field strength in order to understand EMF’s effect on us from either
perspective.
