O
PERATION
M
ANUAL
P
ROMO
®
2000
P
ALAS
®
G
MB
H,
M
ARCH
2010,
V
ERSION
V001032010
23
5.3
Error
identification
of
optical
measuring
devices
The
absolute
fault
f
abs
of
a
measuring
device
results,
if
one
subtracts
the
value
(desired
value)
X
s
from
the
displayed
or
indicated
value
(actual
value)
X
i
and
takes
the
absolute
value
of
this
difference:
f
abs
=
|
X
i
‐
X
s
|
•
The
relative
fault
f
rel
results
from
dividing
the
absolute
fault
through
the
reference
value
X
bw
:
f
rel
=
f
abs
/
X
bw
•
When
indicating
the
relative
error,
the
reference
value
is
to
be
indicated
as
well.
As
reference
values
can
be
selected
e.g.
the
final
value
of
the
measuring
range,
the
measur
‐
ing
range
and/or
interval
width
or
„the
correct
“value.
•
To
determine
the
Q
0
distribution,
the
particle
number
up
to
class
x
i
is
added
and
to
be
divided
through
the
total
of
all
measured
particles
(see
tables
on
the
next
page,
column
Q
0
).
n
Q
0(xi)
=
n
i
/n
ges
i
=
1
Please
note
that
the
so
achieved
Q
0
(x
i
)
value
has
to
be
applied
at
the
upper
limit
of
the
class.
5.4
Advantages
of
counting
measuring
procedures
•
Always
high
resolution,
e.g.
128
channels
over
the
measuring
range,
as
characterization
and
number
determination
are
carried
out
directly.
•
Therefore,
monodisperse
particles
can
be
measured.
•
Therefore,
also
multimodal
particle
size
distributions
with
narrow
total
distributions
e.g.
<
1
µm
can
be
measured.
•
Quick
measuring
procedure.
•
Display
of
time
run.
•
Identifies
also
single
big
particles.
•
Particular
advantages
of
counting
procedures
with
optical
measuring
volume
limit.
‐
In
‐
situ
‐
measurement
possible:
•
in
chemically
aggressive
media
•
in
high
temperatures
•
under
high
pressures
•
in
high
concentrations