a first test unit the breakable seal between the incubation chamber and the test chamber of a second test unit can be pierced and a second detection assay performed this cycle can be repeated until such time as a positive result is reported or all detection units through which the fluid specimens passed have been used or a period of time has elapsed without positive detection that suggests that no target organism existed in any of the fluid specimens in a second embodiment a single monitoring device can be used in a detection assay for one fluid or swab specimen after which the detection units used in that determination are disposed and new detection units are moved into place to detect microorganisms in a distinct specimen in this manner the detection device reduces or eliminates the occurrence of false positives or false negatives via the ability to repeat detection tests at a given location because each monitoring device contains a plurality of detection units each monitoring device can also be used to assay distinct fluid specimens after any detection unit within a monitoring device has been inoculated and assayed separate detection units can be inoculated with fresh fluid specimens derived from air liquid or swab samples in one embodiment the plurality of detection units may each be directed towards the detection of a specific pathogen different from the pathogens detected by the other units in the plurality in this way the plurality may be used to detect the presence or absence of several different microorganisms at one location in another embodiment the plurality of detection units may all be directed towards the same pathogen e g anthrax in this way the plurality may be used to detect the presence or absence of one pathogen at.