Abstract: An indicator sheet for an autoclave test pack wherein a pair of porous masses (10) are held in close superimposed relationship by means of a clamp (13) with the indicator sheet (12) sandwiched between them. The indicator sheet (12) has printed thereon a pattern of markings (14) formed from one or more substances which are adapted under steam sterilizing conditions to provide an indication of the presence of air and/or excessive moisture such that each is evident and individually identifiable.

Abstract: A device for testing the efficiency of autoclaves of the type used in hospitals for steam sterilizing porous loads such as surgical dressings, and particularly for detecting the presence of air in such a system, comprising first and second porous masses (10, 11) of a substantially man-made material such as spun bonded polypropylene, superimposed so as to sandwich therebetween an indicator sheet (12) and a pair of porous and absorbent sheets (12a). This assembly is held firmly together within a perforated stainless steel box (13) having a closable lid (14). For the test the whole device is placed in a steam sterilizer under normal working conditions. Subsequently, the test device is removed and the indicator sheet (12) inspected, any color variation across the sheet providing an indication of incomplete sterilizing conditions.