Airflow Control with Airflow Measurement
Airflow control with integral flow measurement is used when pressure independence is necessary for the air handling system. Waddell offers several airflow measurement technologies, including Differential pressure, Thermal Mass Flow, & orifice.
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Differential pressure measures the
velocity (dynamic) pressure of the airflow.
This is a very common & accurate method of measuring airflow. -
Thermal Mass Flow sensing relates the heat
convected to the air stream to the velocity
of the air stream passing the sensor. Since
there is no relationship to velocity pressure, the velocity reading of the air is independent of density of the air. -
The orifice method measures the pressure
drop across an orifice, which is in proportion
to the airflow through the orifice. This method is often used for contaminated or corrosive air.
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Airflow Control with Airflow Measurement Products
Overview of Flow Stations (805)
Bulletin 805 is an excellent overview
of the WPD with various Air Flow
Measurement Technologies.
WPD with Differential Pressure Station (861-b)
The WPD & the 861 differential pressure
airflow station is economical & precise
method of measuring & controlling
the airflow.
WPD with Averaging Flow Stations (863/820)
Often small duct systems are complex
& velocity rates are not uniform.
The 863 flow averaging station is ideal
for this application.
WPD with Orifice Flow Station (865)
The time proven WPD & the 865
orifice airflow station is an accurate
non complex device where accurate
flow control & non-clogging flow
measurement is required.
WPD with Mass Flow Station (868)
The WPD is suitable for a very wide
range of flow rates. The combination
with the 868 thermal flow measurement,
airflow control ranges from a maximum
flow to close to 100 fpm. Normal
up & downstream duct connections.