A sensor system for detecting a property of or within an absorbent article comprising a front 101 and back, a garment-facing layer 150, a first transmitter and a first and second sensor 131. The first and second sensor have a first and third status respectively and are capable of changing to a second and fourth status respectively. The first transmitter is capable of sensing a change in status of the first and second sensor. The first transmitter is programmed to send a signal to check the status of the first sensor non-continuously and this transmitter is programmed to send a signal to check the status of the second sensor only once the first sensor has the second status. Wherein the first and or second sensor are capable of sensing an aspect of the absorbent article associated with insults of bodily exudates namely a colour change through the garment facing layer.
