#$%^&*AU2016277610B220180719.pdf#####ABSTRACT A nebuliser cup for maintaining a safe level of liquid during nebulization, the cup 5 comprising a liquid level sensor comprising: a first element sensing liquid at or below a position corresponding to a filled liquid level in the nebuliser cup; a second element electrically isolated from the first element and located at a position corresponding to a filled liquid level in the nebuliser cup; and wherein when the cup is not filled with a liquid to the filled liquid level, the first element, the liquid and the second element do not 10 form an electrically coupled circuit; and when the cup is filled with a liquid to the filled liquid level, the first element, the liquid and the second element together form an electrically coupled circuit.