Device and method for measuring the level of liquid in a container

A method of operating a filling level measuring device for measuring a filling level in a liquid gas bottle through a wall thereof via an ultrasound, which includes an ultrasonic measuring head, a controller, and a fastening device, the method comprising:

• fastening the filling level measuring device to the liquid gas bottle such that the ultrasonic measuring head is pressed against the wall of the liquid gas bottle,
• wherein a sampling rate is used which is situation-dependent, and
• wherein the controller reduces the sampling rate or discontinues the measurements altogether if the controller detects no communication of the filling level measuring device with an external device.

A method of operating a filling level measuring device for measuring a filling level in a liquid gas bottle through a wall thereof via an ultrasound, which includes an ultrasonic measuring head, a controller, and a fastening device, the method comprising:

• fastening the filling level measuring device to the liquid gas bottle such that the ultrasonic measuring head is pressed against the wall of the liquid gas bottle,
• wherein a sampling rate is used which is situation-dependent, and
• wherein the controller detects a low filling level, the controller proceeds from an evaluation of a first echo of the ultrasonic waves generated to an evaluation of a second or third echo of the ultrasonic waves.

A method of operating a filling level measuring device for measuring a filling level in a liquid gas bottle through a wall thereof via an ultrasound, which includes an ultrasonic measuring head, a controller, and a fastening device, the method comprising:

• fastening the filling level measuring device to the liquid gas bottle such that the ultrasonic measuring head is pressed against the wall of the liquid gas bottle,
• wherein a sampling rate is used which is situation-dependent, and
• wherein when the filling height is low, the transmitting power of the ultrasonic measuring head is reduced.