Silver-silver chloride plunge electrode needles and chloriding monitor (bioelectric signal recording application)

A plunge electrode is made from a hypodermic needle with one side cut open and multiple electrodes exposed from tip to base. A method for constructing chlorided silver electrode plunge needles is explained, and problems associated with electrode chloriding are pointed out. The small surface area of these electrodes makes empirical methods of chloriding difficult to use. A monitor for the testing and chloriding of a twelve-electrode plunge needle was constructed. This system continuously measures the impedance of the electrodes during chloriding.