I use them and the noise they make is why some still refer to bite alarms as buzzers. There are no single bleeps, peeps, pips or any of that warbling that goes on with the Delkims. I'm sure the buzzer from the Heron's sounder box would be well at home in the servant quarters of a mansion house.
A vane anemometer thus combines a propeller and a tail on the same axis to obtain accurate and precise wind speed and direction measurements from the same instrument. The speed of the fan is measured by a rev counter and converted to a windspeed by an electronic chip.
What is Wind Direction ? Wind direction is the direction from which the wind is blowing; the direction from which the air is moving. It is not the direction the wind is blowing toward. Wind direction is measured with reference to 360 degrees on the compass (true North), and expressed to the nearest degree, going in a clockwise direction, or to any one of the 16 points on a compass (N, S, SE, WSE, etc...).