Example:
Radiated
Emission
Measuremen
ts
The
pro cedure
used
to
make
radiated
emission
measuremen
ts
dep ends
on
the
nature
of
the
test
site.
If
y
ou
make
measuremen
ts
in
a
semi-anec
hoic
enclosure
or
at
a
remote
site
where
ambien
t
signals
are
b elow
the
limits,
y
ou
may
use
a
quic
k-lo
ok/full-span
pro cedure
similar
to
the
pro cedure
used
to
make
conducted
measuremen
ts.
If,
on
the
other
hand,
y
ou
make
measuremen
ts
at
an
op en
site
where
n
umerous
ambien
t
signals
are
ab o
v
e
the
limits,
then
y
ou
m
ust
use
one
of
these
t
w
o
pro cedures:
Make
preliminary
measuremen
ts
in
a
shielded
enclosure
where
ambien
t
signals
are
not
presen
t.
F
requencies
at
whic
h
emissions
are
noted
are
then
rec
hec
k
ed
at
an
op en
site.
(F
or
CISPR
measuremen
ts,
a
shielded
enclosure
can
b e
used
to
lo
cate
emissions,
but
not
to
measure
emission
amplitudes.)
or
Select
a
relativ ely
narrow
span
(for
example,
1
MHz)
then
tune
the
cen
ter
frequency
,
k
eeping
track
of
emissions
as
they
are
observ
ed.
The
relativ ely
narrow
span
is
required
in
order
to
distinguish
b et
w
een
ambien
t
and
signals
from
the
EUT.
A
t
op en
sites,
ambien
t
signals
m
ust
b e
distinguished
from
signals
emitted
b
y
the
EUT.
Compile
a
list
of
ambien
t
signals
that
are
alwa
ys
or
almost
alwa
ys
presen
t
in
a
given
en
vironmen
t.
This
allo
ws
some
signals
to
b e
recognized
as
ambien
ts
based
solely
on
the
frequency
of
observ
ation.
Sounds
pro duced
b
y
emissions
from
a
particular
EUT
may
b e
unique
and
recognizable.
Similarly
,
ambien
t
signals
can
often
b e
iden
tied
b
y
sound
alone.
F
or
this
reason,
a
sp eak
er
is
built
in
to
the
quasi-p eak
adapter.
HP
8572A
EMI
Receiv
er
User's
Guide
Making
Typical
Measurements
4-29
