Oriented purple membranes produce the transient photoelectric signal when irradiated by a pulsed light. This photoelectric signal contains three main components(each called B1, B2, and B3) with different lifetimes ranging from picosecond to millisecond. B1 and B2 are the internal vectorial components since the reflection of the inner charge change of the membrane. Therefore, the direction of B1 and B2 depends on the orientation of purple membrane in the film. However, B3 is not the vectorial components because the direction of B3 does not depend on the orientation of purple membrane in the film but depends on the pH of the film modified electrode in electrolyte solution.