Rainfall intensity sensor
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsBernard Vonnegut, Terry E. Battalino
Life of this patent
Estimating the term…
Abstract
An instrument having a logarithmic response is provided which continuously easures rates of rainfall over a range of from 0.3 to 350 mm/hr by determining the electrical power required to evaporate the water as it arrives on an exposed sensor. The sensor determines the flux of rain or cloud water arriving on its surface and consists essentially of a porous, water absorbent, dielectric material held between two metallic electrodes across which a fixed electrical potential is maintained. The water is evaporated by electrical heating as it arrives on the surface, and the amount of power required is a measure of the mass flux of water to the collecting surface.
Claims21
A direct-reading mass flux precipitation gauge that can be used to measure the liquid water content of clouds as well as rates of rainfall and snowfall comprising:
- a sensor having a projected exposure area made of a porous, water absorbent, dielectric material in layer form which becomes electrically conductive when wet;
- a metallic electrode on each of the opposed surfaces of said porous layer holding said layer therebetween;
- means for maintaining a fixed electrical potential across said electrodes so that water or snow arriving on the exposed area of said porous layer is rapidly absorbed by said porous layer, substantially reducing the electrical resistance at the points of absorption and causing an electrical surge that heats the wet portion of the porous layer and evaporates the water;
- means for determining the amount of power required to evaporate the incident precipitation and thereby measure the mass flux of precipitation to the porous layer;
- and
- means for deploying said sensor in the atmosphere.
A precipitation intensity sensor comprising:
- a cylindrical metal body open at one end and a cap made of dielectric material closing said open end;
- a porous water-absorbent dielectric material covering the external cylindrical surface of said body;
- a highly conductive external electrode in strip form contacting and uniformly spaced about said external dielectric covering;
- an electrical heating element mounted within said body and means connected to said heating element for heating the interior thereof to maintain body temperature substantially at a desired differential above ambient temperature, said body and said external electrode electrically coupled by precipitation absorbed by said dielectric material;
- and
- means for deploying said body in the atmosphere.
Dependencies are inferred from the claim text.