Abstract: A level sensor for providing an indication of liquid level in a container. The level sensor including an ultrasonic transducer for emitting an ultrasonic signal to the surface of the liquid and for detecting a return signal, reflected from the surface. A controller instructs the transducer to emit ultrasonic signals and receives an indication that a return signal has been detected. The controller including a timer for measuring the time period between emission of the ultrasonic signal and receipt of a return signal, the determined time period providing an indication of the liquid level. A radio transmitter receives an indication of the liquid level and transmits a radio liquid level signal to a remote output unit.