The sanitary appliance comprising a receptacle provided with a flow surface and further comprising at least one sensor for sensing flow of urine (a physiological solution) located at a distance from the flow surface of the receptacle, characterised in that the sensor comprises a resonance circuit. Urine flow may be identified at the flow surface in that: (1) a first voltage is provided to a resonance circuit to be modified into a second voltage; (2) the second voltage is sensed and (3) the second voltage is compared with a reference value for identification of urine flow. Furthermore a dirt layer with a thickness at the flow surface may be identified. |