Anemometer

Author:  Max Knobel ET AL
Source:  US Patent 2,316,255
Doc ID:  1941008
Year of Publication:  1941
Abstract:  
This invention relates to anemometers and more particularly to anemometers capable of measuring or comparing air-flow at low velocities. In attempting to measure air-flow in refridgerators, it was found that the anemometers on the market were inoperative or unreliable at such low air velocities. The manufacturers of anemometers made no pretension that their product would measure an air-flow of less than 10 ft. per minute. It is an object of our invention to provide a sensitive anemometer which is capable of satisfactorily measuring air-flow at rates below the limits at which the present anemometers are operative.