This Standard specifies the principal dimensions of lamp caps and requirements for lampholders for use on double-capped tubular lamps for voltages not exceeding 250 voltolts. Since the design of lampholders and fittings must provide for suitable entry of the lamp, it also includes requirements regarding the disposition of a combined pair of lampholders embodied on a fitting for such lamps, one or both of these lampholders having a movable contact.
