1970 年 39 巻 2 号 p. 119-126
As a method of measuring the mass transfer rate dM/dt, the rate of change in the intensity of specularly reflected light dI/dt has been employed. In the case of frost deposits, the relation dM/dt=-KdI/dt (K: const.) is shown to hold particularly well. Experiments show that dM/dt is proportional to σ, Re1/2, n1/2 and ƒ(Tm), where σ is the supersaturation with respect to ice, Re. the Reynolds number, n the number of ice islands per unit area of mirror surface and ƒ(Tm) a function of mirror temperature. In addition, n is proportional to Re1/2, exp[ln2(Se)] and (ΔTm/Δt), where Se is the saturation ratio and (ΔTm/Δt) the cooling rate of the mirror surface. The optimum sensitivity for dew-point instrument must be set on the basis of these results.