Use of electrical soil-moisture units in mountain soils

TitleUse of electrical soil-moisture units in mountain soils
Publication TypeConference Proceedings
Year of Conference1955
AuthorsHorton, J. S.
Conference Name23rd Annual Western Snow Conference
Series TitleProceedings of the 23rd Annual Western Snow Conference
Date PublishedApril 1955
PublisherWestern Snow Conference
Conference LocationPortland, Oregon
KeywordsColman units, Soil moisture measurements

A procedure for measuring soil moisture at several depths in a mountain soil mantle using fiberglass, monel metal units (Colman Units) is presented. These units have a thermister (temperature element) encased in the monel metal case. Three wire leads are brought to the surface through a pipe to prevent rodent damage. The meter is an alternating current design circuit to measure impedance In milli-amps, thus averting a direct resistance reading that would be contaminated by soil salts or acids. The milli-amps readings are converted to Ohms by a calibration chart furnished with each meter. The process of calibrating the units to soil moisture by field and laboratory procedures is discussed. Calibration curves are exhibited. A discussion of results is included in the text of the paper.