See
also  Laminar
Flow Elements -
Technology
for the Precise Measurement of Gas FlowLinearity
Unlike
conventional methods where one finds a quadratic
relationship between the differential pressure
and the flow rate, the LFE produces a low
differential pressure that is linearly
proportional to the flow rate. This is due to a
system of minute parallel capillary passages
inside the LFE.
Large operating
range
The linear
relationship between the flow meter and the
volumetric flow measured makes a large flow range
possible. One still obtains valid results for
less than a hundredth of the full scale
differential pressure.
Insensitive to
pulsations
Even for a
pulsating flow reliable measurement is obtained.
Small pressure
loss
The maximum
differential pressure through an LFE is typically
20 mbar (2000 Pascal). This pressure loss is
negligable in a typical system. Where the
pressure loss is significant, LFEs can be
employed with a maximum differential pressure of
1 mbar.
Very Short
Reaction Time
Laminar Flow
Elements react on changes of the flow virtually
without delay. This characteristic does favourite
the LFEs for automated installations.
High Precision
Laminar Flow
Elements with appropriate calibration and sensors
are perfectly suited for measurement with highest
precision demands, which come close to national
and international reference standards.
See also Precision of Flow
Measurement using
Laminar
Flow Elements
Suited for
nearly any flow rate
More than fifty
different LFEs are available in a wide range of
types and sizes. So one can cover any flow range
beginning at a flow of 5 cubic centimetres per
minute required for leak testing up to 4000 cubic
metres per hour for a fan or a blower.
Calibration
LFEs are factory
calibrated and can be delivered in a complete
ready-to-use system including the sensors.
Data processing
and evaluation
The processing
of the sensor data and evaluation of the flow
rate is carried out by the S320 Controller. This
high-performance controller is freely
programmable in a high-level language close to
Pascal. It has been designed using the latest
technologies.
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