Abstract: A method of controlling interelectrode distance when a short occurs between an anode and the cathode metal pad of an electrolytic cell. Anode current data is provided by sampling anode current at a relatively high frequency, and noting any substantial instantaneous increase in current by observing the data over a period of time. Estimates of instantaneous losses in current efficiency over a base period of time due to the shorting are then made. Current efficiency losses are reduced by repositioning the anode via a command from a cell control computer to anode positioning means or by manual adjustment of the anodes in the cell.

Abstract: A method and apparatus are disclosed for monitoring parameters of a film or coating by directing a beam of optical radiation at a film supported on a metal substrate at an angle to the film so as to plane polarize any radiation transmitted through the film, reflecting a portion of the radiation from the interface between the film and substrate, transmitting the radiation through a polarizing medium before and/or after it has been transmitted through the film to block any component of radiation other than that which is or will be transmitted through the film, and transducing the radiation reflected from the interface to provide an output signal which is a function of a parameter of the film.

Abstract: A method and apparatus are disclosed for simultaneously determining thickness and uniformity of a supported film which is at least partially translucent by directing a beam of radiation at the film at an angle thereto, reflecting a portion of the radiation from the interface of the film and substrate back through the film, splitting a portion of the reflected radiation into a first beam portion which is monitored to determine uniformity of film thickness, and a second beam portion which is chopped and split again into a reference beam and a thickness determining beam which are filtered and transduced so that the resulting signals can be compared to determine film thickness.