This standard describes the procedures to be followed and the precautions to be observed in obtaining uniform and reproducible measurements of the electrical characteristics of fluorescent lamps under standard conditions when operated on alternating current (ac) circuits. These methods are applicable both to lamps having hot cathodes - switch-start (preheat-start)@ rapid-start (continuously heated cathodes)@ or instant-start-and to lamps of the cold-cathode variety. The electrical characteristics usually measured are lamp current@ lamp voltage@ and lamp power. In the case of rapid-start lamps@ the power measurements may include both the arc watts1 and the cathode watts. Total lamp power is the sum of arc watts and cathode watts. The methods noted in this standard apply to fluorescent lamps operated at common power-line frequencies (50 and 60 Hz) or high frequency.