It is pointed out that either effective voltage or any other conventional method is not satisfactory to measure the exposure time of capacitor-discharge-type X-ray apparatus. The measurement of unsharpness of the image of an adequate moving phantom is recommended in order to know the exposure time. This article discusses a moving phantom which may be used in routine chest radiography and shows the data which have been obtained by the moving phantom method.
Results obtained by measuring with Geiger's calculating tube the distribution of scattered radiation in a room for a deep therapy are reported and the protection to be furnished in such a room is discussed.
How the sensitivity of intensifying screens is influenced by voltege is investigated with various kinds of screens and the voltage index of the condenser apparatus. Difference in density between high-sensitive and low sensitive screens, and its relation to voltage are examined.
Hoping for a wider use of an electric condenser apparatus, an improvement has been made of the connection of lines. The apparatus makes possible serial penetrations or indirect roentgenography at any desired time by means of pushing a button while viewing fluorescopic images. While it is easy with an all-wave rectifier apparatus to make a change to viewing-radiography, a condenser appiratus seems to be fit only for ordinary radiography, viewing being carried on by a half-wave rectifier for charging. Therefore, the method presented here would be of special significance.