This standard specifies the energy efficiency limits, energy-saving evaluation values, and test methods for double ended fluorescent lamps (hereinafter referred to as double ended fluorescent lamps) for general lighting. This standard applies to the following two types of lamps: preheating cathode lamps that work on AC power supply circuits with starters and can work on high-frequency circuits, and preheating cathode lamps that work on high-frequency circuits. The following normative references are essential for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest version (including all modification orders) applies to this document. GB/T 10682 Performance Requirements for Double ended Fluorescent Lamps GB 18774 Safety Requirements for Double ended Fluorescent Lamps 3 Terms and Definitions As defined in GB/T 10682 and the following terms and definitions apply to this document. 3.1 Initial Luminous Efficiency for Double capped Fluorescent Lamps The ratio of the measured initial luminous flux to power of a double capped fluorescent lamp under standard test conditions, in lumens per watt (lm/W). 3.2 Minimum allowable values of energy efficiency for double capped fluorescent lamps The minimum allowable values of energy efficiency for double capped fluorescent lamps under standard testing conditions. 3.3 Evaluation values of energy conservation for double capped fluorescent lamps The minimum standard value that the initial optical effect of energy-saving double capped fluorescent lamps can achieve under the standard testing conditions