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.
To measure wind speed and direction, a meteorologist uses an anemometer. One type of anemometer is a horizontal windmill; it has small plastic cups affixed to metal arms on a pivot that spins in response to the wind. A separate vane indicates the wind direction.