This invention relates generally to patient monitoring systems and more particularly concerns devices and systems used to monitor bed patients in hospital or other care-giving environments. In accordance with a first aspect of the instant invention, there is provided a wetness detector for use in patient monitoring situations and which is adjustable in its degree of sensitivity to wetness. It contains at least two conductive regions placed on a non-conductive base and which are preferably separated laterally by some distance. Isolated electrical leads are attached to each conductive region. Electrical current passes much more readily between the two conductive regions when an electrolytic solution such as urine is present within the switch, thereby making it possible for a separate electronic monitor to determine when wetness is detected.