MIL-E-23919A, MILITARY SPECIFICATION: ELECTRODES, REFERENCE, CIRCULAR, CORROSION PREVENTIVE, (FLUSH TYPE): SILVER-SILVER CHLORIDE (18 APR 1983) [S/S BY MIL-DTL-23919B]., This specification covers the requirements for circular silver-silver chloride flush type reference electrode used in impressed current cathodic protection systems. The reference electrode provides the control signal to the impressed current system and may be used to monitor the system operation. It includes features of design and fabrication of these electrodes, including alternate components.