
O
PERATION
M
ANUAL
P
ROMO
®
2000
P
ALAS
®
G
MB
H,
M
ARCH
2010,
V
ERSION
V001032010
20
5
Ensuring
correct
test
conditions
In
case
of
disadvantegeous
test
conditions,
the
measuring
result,
i.e.
the
determined
particle
size
distribution
of
the
single
measurements,
can
considerably
differ
from
the
actual
existing
values
in
the
aerosol
flow.
Therefore,
please
pay
attention
to:
Representative
sample
taking
Isokinetic
sampling
Minimal
particle
losses
through
the
aerosol
transport
No
coincidence
error
Please
note:
Palas®
regularly
offers
training
courses
about
these
topics.
As
a
basic
principle,
the
Promo®
system
can
only
measure
and
display
data
it
has
been
registred
in
its
optical
measuring
volume.
That
means,
the
aerosol
sampling
flow
should
be
lead
there
as
straight
as
possible.
Therefore,
please
pay
attention
to:
‐
short
tubes
for
the
aerosol
‐
if
possible,
metal
tubes,
in
no
case
longer
plastic
tubes
(high
particle
separation
due
to
elec
‐
trostatic
charging)
‐
vertical
aerosol
guiding,
as
bigger
particles
(>
5
µm)
sediment
respectively
the
aerosol
sepe
‐
rates
As
basic
principle
of
all
counting
scattered
light
measuring
technologies,
just
one
single
particle
may
be
in
the
optically
limited
measuring
volume
of
the
sensor
at
the
same
time.
This
due
to
the
fact,
that
the
scattered
light
of
the
single
particle
is
being
evaluated
for
the
determination
of
the
particle
size.
If
more
than
one
particles
are
in
the
measuring
volume
at
the
same
time,
these
particles
are
measured
as
one,
i.e.
the
particle
is
being
measured
too
big
and
the
number
to
small.
To
measure
correctly,
one
has
to
dilute.
The
Palas®
dilution
systems
have
proven
themselves
in
practice
at
the
market.
If
requested,
they
can
be
heated
and
be
used
in
overpressure
and
under
‐
pressure.
If
a
measurement
has
been
done
correctly
with
a
dilution,
this
measurement
supplies
a
finer
par
‐
ticle
size
distribution
and
a
higher
particle
concentration
as
result,
compared
to
a
measurement
in
coincidence.
A
separation
efficiency
that
was
measured
in
coincidence
is
always
worse
compared
to
one
being
measured
under
correct
conditions.
The
advices
given
here
are
surely
not
sufficient
to
ensure
a
correct
measurement
in
any
case.
In
case
of
particular
problems,
please
contact
Palas®
directly.
5.1
Measurement
errors