Abstract: A gear pump includes at least a first and a second rotatable element, wherein the first rotatable element has a toothing system which interacts with a toothing system of the second rotatable element. The gear pump further includes a housing in which the first and/or the second rotatable element are at least partially arranged, and at least one transmitter, which is arranged on the housing, for exciting acoustic waves in the housing. At least one receiver is arranged on the housing, for receiving the acoustic waves which are excited in the housing. Information about properties of the gear pump and/or of a pumping medium can be determined by evaluating a signal which is generated by the receiver when the acoustic waves are received.

Abstract: The invention relates to a toothing arrangement, having at least one first element (11) which has a toothing (111), and having at least one second element (12) which interacts with the first element (11). According to the invention, at least one receiver (3) is provided which is arranged on the first or on the second element (11, 12) and which serves for receiving acoustic waves (SAW) which are incited in the first and/or second element (11, 12), wherein information regarding characteristics of the toothing arrangement (1) can be determined through evaluation of a signal which is generated by the receiver (3) upon receipt of the acoustic waves (SAW).