katsetatava liiteseadisega talitleva lambi madalaimale hädaolukorras pärast normaaltoite tõrget võimalikult tekkivale ja seejärel hädatalitluse tunnuskestuseni püsivale pingele vastava valgusvoo ja võrdlusliiteseadise kaudu toidetava sama lambitunnuspingele ja tunnussagedusele vastava valgusvoo suhe, ratio of the luminous flux of the lamp, operated with ballast under test, at the lowest voltage which canoccur during emergency mode, after failure of the normal supply and continuously to the end of rated duration of operation, to the luminous flux of the same lamp operated with the appropriate reference ballast supplied at its rated voltage andfrequency