Vaisala WXT536, Руководство пользователя

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Chapter 3 ______________________________________________________ Functional Description
VAISALA_______________________________________________________________________ 29
CHAPTER 3
FUNCTIONAL DESCRIPTION
This chapter describes the functions of the WXT530 series transmitters.
Wind Measurement Principle
The transmitters use Vaisala WINDCAP sensor technology for wind
measurement.
The wind sensor has an array of three equally spaced ultrasonic
transducers on a horizontal plane. The unit determines wind speed and
wind directions by measuring the time it takes the ultrasound to travel
from one transducer to the other two.
The wind sensor measures the transit time (in both directions) along the
three paths established by the array of transducers. The transit time
depends on the wind speed along the ultrasonic path. For zero wind
speed, both the forward and reverse transit times are the same. With
wind along the sound path, the up-wind direction transit time increases
and the down-wind transit time decreases.
WXT536 WXT535 WXT534 WXT533 WXT532 WXT531
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