INFORMATION SYSTEM, COMMUNICATION MODULE, WATER PURIFIER, AND STATE-QUANTITY DETECTION METHOD

摘要

This invention notifies a user of a handheld terminal when a state quantity for a device equipped with a state-quantity display apparatus has a prescribed value. Said state-quantity display apparatus generates an electrical signal corresponding to the aforementioned state quantity and performs display. This communication module is provided with the following: a detection unit that, on the basis of the aforementioned electrical signal, detects when the state quantity has the abovementioned prescribed value and outputs detection information indicating that fact; and a transmission unit that transmits a radio signal containing said detection information. The abovementioned handheld terminal receives said radio signal and presents presentation information pertaining to the abovementioned device on the basis of the detection information contained in the radio signal.