This standard describes the essential features and operating characteristics of reference ballasts for high-intensity-discharge and low-pressure sodium lamps to operate on 60-Hz sinusoidal ballast systems. The items specified are those that have been found necessary to ensure accurate and reproducible results when either lamps or ballasts are being tested. The specific values of rated input voltage and impedance needed for each site of lamp are listed in the appropriate American National Standards for high-intensity-discharge and low-pressure sodium lamps, ANSI C78.1300 series, ANSI C78.40-1985, Specifications for mercury lamps, or ANSI C78.41-1981, Specifications for low-pressure sodium lamps. For convenience, a list of reference ballast impedances and rated input voltages that were in effect at the time this standard was approved is included in annex A.