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. 27 . accurately without having to rush through the procedure of determining the mass and dimensions. Another indicator for the consistency of the data is the ambient fog temperature. More difficulties persist at colder temperatures where possible unknown microphysical mechanism can account for some of the problems including the development of complicated shapes and polycrystalline crystals below -150C. However, most of the dilemmas resulting from the colder temperatures are technical. One source of technical problems is icing on some important parts of the supercooled cloud tunnel, which occurs more readily on colder surfaces. The affected parts include the honeycombs, where icing within the straws hinders the flow, and the hot wire anemometer, where ice tends to cover the sensor. Another effect, the higher liquid water content at colder temperatures, enhances the icing and increases the supply of fog droplets impacting onto the sensor of the anemometer. A phenomenon that is most prevalent at temperatures below -lOOC and the beginning of the growth period is the uncertainty of the proper starting time and is a result of both the seeding technique for nucleating ice in the supercooled fog and the competition between crystals for available water vapor. At the time of introduction into the suspension chamber, the crystals have already a nonzero radius that contradicts the theoretically assumed initial condition that the particles have no radius at the start of the growth period. Although attempts were made to avoid this contradiction, competition for available moisture among the crystals further complicates the determination of the proper starting time by slowing the diffusion process by some indeterminate factor. This effect becomes somewhat serious duing the initial stages of growth in the suspension tunnel since the seeding method . . . . . . . . .