4.3811.00.000_US-Anemometer-DSP_eng.doc
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1 Application
The
Ultrasonic Anemometer 2D
is used to detect the horizontal components of
wind velocity
and
wind direction
as well as the
virtual temperature
in 2 dimensions.
Due to the measuring principle the instrument is ideal for inertia-free measurement of gusts and
peak values.
The level of accuracy achieved when measuring the air temperature (virtual temperature)
surpasses that of classical methods, in which the temperature sensors are used with weather and
radiation protection, following correction of the influence of damp occurring with certain weather
situations.
Output of the measured values is digital. An RS485 in half duplex mode is available for serial
communication.
Serial output of the data is as a sliding mean.
The sensor arms are automatically heated if necessary with critical ambient temperatures. This also
ensures functionality with snowfall and sleet and minimises the risk of malfunctions due to icing-up.
The model No. 4.3811.00.000 has additional protection from mechanical stresses such as ice
fracture and attack by birds by means of metal encapsulated ultrasonic transformers.
These Operating Instructions relate to the device version 4.3811.00.000. They describe possible
applications and settings.
The
Ultrasonic Anemometer 2D
is factory-set
.
Identification for the factory setting is via the order
No. and "Factory Setting".
Order number and setting
see supplementary sheet "Factory Setting"
In addition, the default settings for device version 4.3811.00.000 are marked in "grey" in these
Operating Instructions.
2
Mode of Operation
The
Ultrasonic Anemometer 2D
consists of 4 ultrasonic transformers, in pairs of two facing each
other at a distance of 200 mm. The two resulting measurement paths are vertical to each other.
The transformers function both as acoustic transmitters and receivers.
The electronic control system is used to select the respective measurement path and its measuring
direction. When a measurement starts, a sequence of 4 individual measurements is performed in
all 4 directions of the measurement paths at maximum speed.
The measuring directions (sound propagation directions) rotate clockwise, first from south to north,
then from west to east, from north to south and finally from east to west.
The mean values are worked out from the 4 individual measurements of the path directions and
used to make further calculations..
