DC recording of the human corneofundal potential

The limitation of an AC technique for the amplification and display of the indirectly recorded human corneofundal potential (CFP)is discussed. A Mingograph M34 with EMT 12 B preamplifiers (Siemens) has been tested with regard to a DC recording of the CFP. With the same purpose the electrical characteristics of two electrode types--a Kaiser lead alloy electrode and a Beckman silver-silver chloride cupped electrode--were examined and a suitable preparation of the skin contact area indicated. Finally the base line stability was evaluated and a comparative study of AC and DC recordings of the CFP presented and subjected to statistical anaylsis.