Its purpose is to check the degree of steam penetration in the case of hollow objects and the efficacy of the air removal system. The test uses a Teflon tube open at one end only (length 1.5 m, internal diameter 2 mm), ending with a Teflon capsule, containing a chemical process indicator. EN 13060 requires for purposes of approval the employment of this apparatus to test cycles for sterilizing hollow load A (for example B cycles). The test is positive if the chemical indicator changes colour in line with the information given by the producer