Verbesserung bezüglich der Spülzuverlässigkeit eines Urinals

This invention relates to a method for maintaining the reliable operation of a sensor detecting a need for flushing a urinal (10). According to the invention, urine stone and/or other such dirt adhered over the area of the flushing-need detecting sensor within the liquid basin of the urinal (10) is removed by means of a vibrator operating over this particular area. In a preferred case, the sensor comprises for example a piezoelectric crystal. In one embodiment of the invention, the sensor is adapted to vibrate by means of a piezoelectric crystal. In a second preferred embodiment, said piezoelectric crystal is set in the immediate vicinity of the sensor, thereby removing the dirt.