Method for chemical detection

摘要

A method for detecting a target substance which includes collecting a substance sample; introducing the substance sample into a substance card having at least one reagent responsive to the presence of the target substance and having a light-transmissive chamber; inserting the substance card into a substance detector device having a photosensor and adapted to receive the substance card; mixing the substance sample with the reagents for a preselected mixing period, thus producing a measurand having a target substance reaction; streaming the measurand through the light-transmissive chamber and illuminating the measurand with a quantity of light for a selectable analysis period, an optical characteristic of the measurand can be measured with the photosensor; and selecting the target substance reaction as a positive reaction or a negative reaction, responsive to the optical characteristic. If the target substance reaction is a negative reaction, the device operator is signalled thereof. On the other hand, if the target substance reaction is the positive reaction, the streaming, illuminating, measuring, and selecting steps are repeated for a selectable number of repetitions. If the target substance reaction remains positive after exhausting the selectable number of repetitions, the device operator is signalled of the positive reaction.