flame-exposure test, smoke-density time curve

[marijka]

Добрый день,

Контекст: Воздушные фильтры, пожаробезопасность, стандарт UL 900

"A Class 2 air filter unit shall not produce flame or extensive (25 or more) sparks which are sustained beyond the discharge end of the test duct when subjected to the flame-exposure test and shall not cause the development of an area of more than 9 2 in. (58 cm2) as measured below the smoke-density time curve".

Все по отдельности понимаю, вместе собрать не могу ...
Основные трудности: "sustained beyond the discharge end of the test duct"
и "development of an area of more than 9 2 in. (58 cm2) as measured below the smoke-density time curvе"

Спасибо