A sterilization test pack may include a shell defining an indicator compartment having a volume; a channel extending between a compartment opening and an exterior opening, the channel being in fluid communication with the indicator compartment through the compartment opening and surrounding atmosphere being in fluid communication with the channel through the exterior opening such that the indicator compartment is in fluid communication with the surrounding atmosphere through the channel, the channel having a length measured between the compartment opening and the exterior opening and a hydraulic radius along the length; and an indicator disposed in the indicator compartment, where a ratio of the compartment volume to the channel hydraulic radius may range from 1000 cm2 to 8000 cm2.