An intermediate check shall be carried our by placing in the smoke chamber a screen representing a gas whose known light-absorption coefficient k, measured as described in item 3.5.1, is between 1.6 m-1 and 1.8 m-1.
Opravi se vmesni kontrolni pregled, tako da se v dimno komoro postavi filter, ki predstavlja plin, katerega znani absorpcijski koeficient k, izmerjen, kakor je navedeno v točki 3.5.1, je med 1,6 m-1 in 1,8 m-1.