Nokia Lumia 920 Manual page 61

possibility that the test measurement may be less than or
greater than the actual RF emitted by the phone. This
difference between the RF test measurement and actual
RF emission is because test measurements are limited by
instrument accuracy, because test measurement and
actual use environments are different, and other variable
factors. This inherent variability is known as
"measurement uncertainty." When FCC conducts post-
grant testing of a cell phone, FCC takes into account any
measurement uncertainty to determine whether
regulatory action is appropriate. This approach ensures
that when FCC takes regulatory action, it will have a sound,
defensible scientific basis.
FDA scientific staff reviewed the methodology used by
FCC to measure cell phone RF, and agreed it is an
acceptable approach, given our current understanding of
the risks presented by cellular phone RF emissions. RF
emissions from cellular phones have not been shown to
present a risk of injury to the user when the measured SAR
is less than the safety limits set by FCC (an SAR of 1.6 w/
kg). Even in a case where the maximum measurement
uncertainty permitted by current measurement
standards was added to the maximum permissible SAR,
the resulting SAR value would be well below any level
known to produce an acute effect. Consequently, FCC's
approach with measurement uncertainty will not result in
consumers being exposed to any known risk from the RF
emitted by cellular telephones.
FDA will continue to monitor studies and literature reports
concerning acute effects of cell phone RF, and concerning
chronic effects of long-term exposure to cellular
telephone RF (that is, the risks from using a cell phone for
many years). If new information leads FDA to believe that
a change to FCC's measurement policy may be
appropriate, FDA will contact FCC and both agencies will
work together to develop a mutually-acceptable
approach.
Updated July 29, 2003
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