Abstract: A method is disclosed which permits evaluation of soil moisture utilizing remote sensing. Spectral measurements at a plurality of different wavelengths are taken with respect to sample soils and the bidirectional reflectance factor (BRF) measurements produced are submitted to regression analysis for development therefrom of predictable equations calculated for orderly relationships. Soil of unknown reflective and unknown soil moisture tension is thereafter analyzed for bidirectional reflectance and the resulting data utilized to determine the soil moisture tension of the soil as well as providing a prediction as to the bidirectional reflectance of the soil at other moisture tensions.

Abstract: A method for measuring with a flexible dipstick the nonvisible level of liquid nitrogen in a container. The dipstick, made of a solid plastic strip having a flat cross-section and a dark color on which is printed a visible scale, is inserted into the liquid nitrogen-containing container for a short time. The dipstick is then rapidly waved in the air to permit frost to form on the cold portion that was immersed in the liquid nitrogen. The dipstick has a relatively high width-to-thickness ratio to provide waveability and flexibility for quickly forming the frost line and for permitting compact storage when not in use.