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Sonic Anemometer
A
sonic anemometer consists of a sensitive apparatus mounted on a shaft
and consists of six ultrasonic transducers arranged in three pairs. The
axes of the transducers are all oriented at 45 ° from the vertical
direction and their projections on a horizontal form between them an
angle of 120 °.
Each
pair of transducers act alternately as transmitter and receiver,
sending in both verses of high-frequency ultrasonic pulses. Every
millisecond the anemometer sends an ultrasonic pulse and this pulse is
sent alternately in the two directions of three axes. The sampling frequency of the anemometer is 100Hz.
The way used in our measures providing for the acquisition of the velocity components U, V, W calibrated (m / s). In
this manner are stored the values of these quantities are fixed and
calibrated, taking into account the effect of the structure and
transducers. Also the transit time is calculated by the speed of sound.
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