Abstract: There are disclosed a method and an apparatus for the measurement of the ice content of snow. Ice content is directly related to the quality of the snow. The method comprises the steps of measuring the weight of ice in the sample by:(1) placing a sample of the snow to be measured in a sample chamber;(2) heating said sample chamber and measuring the heat supplied while measuring its temperature; and(3) calculating the weight of the ice in the sample from the measurements in step (2),and then dividing the weight of the ice in the sample by the total weight of the sample to obtain a value for the snow quality. There is also provided an apparatus for carrying out the described method. The apparatus includes an insulated sample chamber including provision for heating and temperature sensing. The sample chamber is detachably connected to a microprocessor based instrument which controls the heating of the chamber and calculates the ice content from the heat supplied and temperature measurements.

Abstract: A method and an apparatus for controlling the concentration of oxygen and pH of a medium during a bioreaction process in a vessel. The method and apparatus are particularly adapted to a fermentation process. A dissolved oxygen sensor generates a signal corresponding to the pH of the medium and a dissolved oxygen sensor generates a signal corresponding to the dissolved oxygen in the medium. A valve mechanism selectively applies air, N.sub.2, O.sub.2 and CO.sub.2 to the medium. A controller produces a control signal for controlling the operation of the valve means so that a substantially fixed volume of gas consisting of one or more of air, CO.sub.2, N.sub.2 and O.sub.2 are added to the fermenting medium during a period of time. The controller determines in response to the dissolved oxygen and pH signals, the amount of CO.sub.2, O.sub.2 and/or N.sub.2 required to effect dissolved oxygen and pH correction. The controller further adjusts these determined values to compensate for the displacement of the CO.sub.