Abstract
A reflectometer was manufactured by the use of cheap materials such as solar cells, an electric bulb, a drawing paper, a sheet of acrylic resin, and a pipe of polyvinyl chloride resin. The capability of it was similar to that of the commercially available reflectometer. This was used to the determination of black-and-white ratio in figure, the estimation of line width, thd measurement of the starch-iodine reaction rate, and the determination of carbon dioxide reacted with a BTB testpaper. A favorable result was obtained to use it as teaching materials in each case.
