Abstract
Some method of regulation is necessery to maintain day-to-day control of developing and fixing and to keep the variations between various processing units to a minimum. I studied in relation to a degree of exhaustion of the developer, the charactristic curve by using the sensitometric strips and electric signal as variation of current against to the constant voltage. As the result, a degree of exhaustion of the developer had a settled margin of safety for sensitivity. The sensitivity dropped hastily just below the allowable settled margin. The sensitivity dropped hastily just below the allowable settled margin. The variation of sensitivity correspond with the electric signal. It is possible to control the developer automatically with the electric signal.
