Abstract
An integrating actinometer for ultraviolet radiation was constructed. It is operated by a 100 V A.C. power supply. The principle of operation is charging up the photo-electric current due to the incidient radiant energy in a condenser and then discharging and forming an impulse to operate a relay counter.
Experiments on the linearity of the response, errors due to power supply fluctuations and the absolute sensitivity, were carried out. The general performance has been very satisfactory. Above all, the stability against the fluctuations of power supply is the essential merit of this instrument.
