Abstract: A water content detecting device for any type of diaper such as a cloth made reusable diaper, a paper made disposable diaper, or the like includes a sensing unit for sensing the degree of wetness of the diaper and an informing unit for transmitting the information representing the degree of wetness to a nursing person at a remote place. The sensing unit is detachably interposed in the diaper to be detected. The sensing unit is composed of a water impermeable upper sheet, a water permeable lower sheet, and a pair of metal layers placed between the upper sheet and the lower sheet and extending in the longitudinal direction of the sheets in parallel. One of the metal layers is covered with an electrical insulating layer. The informing unit is connected to the sensing unit through a pair of leads, and composed of a water content detecting circuit for detecting the change of electrostatic capacitance between the two metal layers of the sensing unit, a wave form shaping circuit, and an oscillating circuit.

Abstract: Water content sensing and informing system for the disposable diaper composed of a water permeable inner sheet, a water absorber and a water impermeable outer sheet, comprises a water content sensing means consisting of a water impermeable sheet, and a first and second metal layers, the first metal layer being formed on one side surface of the water impermeable sheet, and the second metal layer being formed on the other side surface of the sheet and an informing means, electrically connected to the above two metal layers, for informing that the water content in the diaper exceeds a specific level in response to the change of the electric conductivity between the first metal layer and the second metal layer.

Abstract: Water content sensing and informing system for a disposable diaper consisting of water permeable inner sheet, water absorber, and water impermeable outer sheet, comprises at least one pair of metal layers, one surface of one layer being covered with an electric insulating layer, formed between the water impermeable outer sheet and the water absorber, a detector for detecting water content absorbed in the diaper, and an informing mechanism for informing the detected result. The pair of metal layers is isolated with constant distance to each other and extended in the longitudinal direction of the diaper. The pair of metal layers is formed in a thin layer by a lamination or vacuum evaporation of a metal leaf. The informing mechanism is selected from a visual, auditory, remote informing device using an oscillator and receiver, or combination of these.