The invention comprises a diaper sensor device (1) comprising at least two sensor units (3) each comprising at least a temperature sensor (4) and a humidity sensor (5)； optionally a positional sensor (11)； a microcontroller (2) communicating with the sensors and comprising a transmitter (7) for transmitting data from the sensors； a power unit (6) supplying power to the sensors, the microcontroller (2) and the transmitter (7)； a flexible watertight casing (13), housing the sensors, the transmitter (7), and the power unit (6), and fastening means for fastening the diaper sensor device (1) on the outside of the diaper (12). Furthermore the invention comprises a method and a system for determining the existence and class of human excreta in a diaper.The invention com prises a diaper sensor device (1) comprising at least two sensor units (3) each comprising at least a temperature sensor (4) and a humidity sensor (5)； optionally a positional sensor (11)； a microcontroller(2) communicating with the sensors and comprising a transmitter (7) for transmitting data from the sensors； a power unit (6) supplying power to the sensors, the microcontroller (2) and the transmitter (7)； aflexible watertight casing (13), housing the sensors, the transmitter (7), and the power unit (6), and fastening means for fastening the diaper sensor device (1) on the outside of the diaper (12). Furthermore the invention comprises a method and a system for determining the existence and class of human excreta in a diaper.
