ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH HANOVER United States
The manual measurement of snow density through sample collection and liquid water content by calorimetry can be cumbersome and time consuming, while electronic methods are considerably faster. Field and laboratory experiments were conducted to compare several techniques for measuring snow density and moisture content. Two methods for the measurement of snow moisture were used in both field and laboratory settings the Denoth meter capacitance plate and the Toikka Oy Snow Fork microwave resonance technique. Snow density was measured using three techniques a direct sample measurement rectangular snow scoop snow fork and, in the lab setting, the Bruker Sky-Scan 1173 Micro CT - X-ray scanner using image analysis techniques. Results show that the snow fork densities are generally reliable in dry snow but become inaccurate low in wet snow. Density from direct sampling was on average 0.037 gcc greater than the snow fork density. Densities measured by the Micro-CT were inaccurate once the snow began to melt, primarily due to sample collection and processing technique. For moisture measurements, we found the Snow Fork to be a reliable tool for measuring the moisture content and density of snow. The Denoth moisture values are on average 0.054 by volume higher than the snow fork moisture. All Denoths tested, report similar moisture values, which was encouraging as these devices are over 20 years old and there is no other source for calibration.