Abstract: An oscillatory anemometer for simultaneously indicating wind speed and direction employs a main member free to rotate under the influence of aerodynamic forces about a first axis and a fin mounted near the downwind end of the main member for pivotal movement about a parallel axis betwen two stable positions. The fin swings between the stable positions forcing the main member through inertial overshoot into oscillation about a mean alignment with the wind direction. The frequency of main member oscillation is linearly proportional to wind speed.

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.

Abstract: A two-way fluid flow metering pump for accurately measuring the rate of f of a liquid is disclosed. A section of a cylindrical shaft is disposed in a bearing made of metal or a fairly rigid nondeformable plastic. An indentation or notch is made in a shaft section passing an inlet and outlet in the bearing, and liquid is transported by the indentation or notch from the inlet to the outlet, or vice versa, depending upon the direction of shaft rotation. A rubber or soft plastic seal inserted in an opening in the bearing remote from the inlet and outlet deforms and conforms to the shaft indentation at each rotation so that the liquid is not transported past the seal.