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.
The WM-4 measures wind speed, wind direction, temperature, relative humidity and compass direction, and calculates wind gust, dew point, wet bulb and dry bulb temperature, Delta T, wind chill and heat index.