Abstract: The invention relates to a method for rendering ultrasonic signals audible that is characterized in that the temporal dynamic range of the ultrasonic signal is maintained. The amplitude profile of the ultrasonic signal picked up in the time domain remains unaltered. The frequency shift from the ultrasonic range to the audible range is possible up to a factor of 32 using the present invention.

Abstract: The invention relates to a gas bubble sensing device (1) for sensing gas bubbles in a liquid. In order to provide a reliable detection of inadmissible gas bubbles at minimum cost and required installation space, the invention provides that the gas bubble sensing device (1) comprises two ultrasonic emitters (2, 3), which are both connected to one ultrasonic signal generator (10) in a signal transmitting manner. A gas bubble sensing device senses gas bubbles in a liquid. The gas bubble sensing device comprises two ultrasonic emitters, which are both connected to one ultrasonic signal generator in a signal transmitting manner. Further, the gas bubble sensing device comprises two control devices that are each connected to one of the signal processing devices in a signal transmitting manner, wherein one of the control devices comprises an output port, at which it provides a synchronization signal during operation.

Abstract: The invention relates to a device for the contactless flow measurement of fluids in flexible tubes.