www.Siargo.com
MF4700
User
Manual
27
|
P a g e
8.
Technical
notes
for
the
product
performance
8.1
Measurement
principle
The
products
utilize
the
Company’s
proprietary
micro
‐
machined
(MEMS)
calorimetric
sensing
and
data
process
technology.
A
thermal
signal
generator
with
a
pair
of
sensing
elements
at
the
up
and
downstream
of
the
microheater
is
precisely
manufactured
and
separated
at
predefined
micrometer
distances
on
a
chip
surface
with
excellent
thermal
isolation.
When
a
fluid
is
flowing
through
the
sensing
chip,
the
fluid
carries
the
thermal
signal
downstream.
The
sensing
elements
register
the
temperature
differences,
further
correlated
to
the
fluid
mass
flow
rate
via
the
calibration
process.
The
calorimetric
sensing
approach
offers
a
large
dynamic
range
with
a
better
performance
against
the
environmental
parameter
alternations.
Please
refer
to
the
company's
US
patents
and
other
publications
made
available
to
the
public
for
additional
information.
8.2
Precautions
for
the
best
performance
of
the
product
8.2.1.
Comparison
with
a
third
party
reference
meter
It
is
very
common
that
a
user
may
compare
the
data
from
the
product
with
a
third
‐
party
reference
meter,
and
in
many
cases,
there
could
be
some
discrepancies.
When
performing
such
a
comparison,
please
note
that
the
reference
meter
should
have
a
better
‐
specified
accuracy
(about
1/3
of
the
product),
and
pay
special
attention
to
the
differences
in
the
reading
accuracy
and
full
‐
scale
accuracy.
A
full
scale
accuracy
=
reading
accuracy
x
(full
scale
flow
rate/
set
point
(current)
flow
rate)
Another
key
point
to
compare
the
different
flow
meter
is
that
as
long
as
the
fluidic
flow
is
a
continuous
flow
without
pulsation,
then
the
fluidic
dynamic
will
have
the
system
following
the
Bernoulli
equation:
Figure
8.1.
Measurement
approach
illustration.
