Abstract
We measured the permeability of 60 different oilpaper. For the measurement of permeability of visible ray, we used the Matsuda's permeability meter; for insolation energy, the Robitzsch pyrheliograph and for ultra-violet rays the ultra-violet ray meter of C. M. O. type. The result of measurement is shown as the table No. 1 C (A is permeability of visible ray, B is that of insolation energy, C is that of ultra-violet ray).
The permeability of visible ray depend upon quantity of oil which is applied for the paper, and thickness of paper chiefly; and sort of oil and manufacturing method have not big effect upon them.
The permeability of insolation energy (P) depend upon the altitude of sun (h). P=a+bh There are highly correlation between permeability of visible ray (x) and that of insolation energy (y).
γ=+0.776 (P<0.05) y=1.536x-63.2
We can regard x as the approximate value of permeability, but y is only one example of measurement and is not the approximate value. Therefore correlation between x and y is not so high. But when we measure the approximate value of insolation permeability, correlation between x and y become more high, and we can surmise insolation permeability of the oil-paper from the measurement value of the permeability meter briefly.
The permeability of ultra-violet ray is very small as compared with that of visible ray and insolation energy. The value, which are recorded table No. 1 (C), are only one example of measurement and are not the approximate value of true permeability.
