DYACON
®
, Inc
Theory of Operation
Sensors
Wind Direction Sensing
The wind direction uses a non-contact magnetic sensor. Unlike potentiometer systems, the sensor
has no dead spots or wear components.
Wind direction is sampled every 50 ms. A 20 sample running average is calculated in about 1 s
and updated every 50 ms.
Wind Speed Sensing
The anemometer uses two magnets, 180° opposite at the perimeter of the anemometer hub. A reed
switch is used to detect rotation.
A 4-sample running average of the switch time is used for wind speed. Measurement response is a
function of wind speed. At 2.5 m/s, the wind speed response is about 1 s.
The wind speed value is updated with each switch closure or half turn of the anemometer.
A deceleration algorithm is used to ensure the running average is accurate as the wind speed
approaches zero.
Architecture
A range of low power strategies are employed in WSD-1 to ensure optimal low power while
providing reliable and accurate measurements across the full environmental range.
A low power microcontroller is central to WSD-1 performance. The microcontroller manages the
rotation sensor and reed switch timing, scaling and applying calibration values as required. The
microcontroller also manages the Modbus protocol and other internal functions, such as
EEPROM interface and bootloader functions.
The microcontroller utilizes low-power strategies, leveraging multiple low power modes and
optimized code execution.
Mi-Met WSD-1 Manual
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