A Preliminary Experiment of Standard Measurement of Liquid Water Content of Snow by Buoyancy Difference Method with Phase Change

Abstract

The method of standard measurement of liquid water content of snow by the buoyancy difference method with phase change has been investigated experimentally.The method, based on the measurement of the difference in buoyancy between ice and water in a suitable liquid, is thought to be employed at either of the following two processes : 1) Freezing process : The first weighing of an appropriate amount of wet snow as the sample is made in the liquid at 0°C. This liquid is lower density than ice and is insoluble against water. Then, the sample is cooled to freeze its water portion. After the freezing, the second weighing is carried out in the same way as the first.The difference in weight between the first and the second (equal to the difference in buoyancy) indicates the amount of water in the sample.2) Melting process : The first weighing is carried out under the same conditions as those of the freezing process. Then, the sample is warmed to melt its ice portion. After the melting, the second weighing is done in the same way as the first. The difference in weight between the first and the second indicates the amount of ice in the sample.In this paper, it is shown that the melting process is more suitable for application of the method than the freezing process, because in the latter the air is separated as bubbles in the freezing water portion.This experiment is carried out with four compornents as follows : 1) Weighing system : Spring balance, accuracy ± 0.4 mg.2) Temperature control system : Peltier cooler and PID controller, temperature regulation ± 0.015°C.3) Liquid : Kerosene, density 0.820 g/cm3.4) Sample : Distilled water, about 4 g.