A device for measuring fluid flow speed, comprising: an acoustic resonance cavity through which a fluid can flow, the fluid having a temperature within an operating temperature range, the acoustic resonance cavity capable of supporting an acoustic standing wave, wherein the frequency of the acoustic standing wave varies with the temperature of the fluid over the operating temperature range, thereby defining an operating frequency range; at least two acoustic transducers, respectively for generating and detecting the acoustic standing wave, wherein a frequency response of said transducers varies over said operating frequency range; characterised in that it further comprises an electric network connected to each transducer, said electric network comprising at least one inductive and at least one capacitive component; wherein the at least one inductive and at least one capacitive component define, together with the connected transducer, a resonance behaviour in which signals in a part of the operating frequency range in which the transducer has a first sensitivity are preferentially amplified relative to signals in a part of the operating frequency range in which the transducer has a second sensitivity, wherein the first sensitivity is lower than the second sensitivity, so that variations in the amplitude of signals propagated through the acoustic resonance cavity, the two acoustic transducers and the connected electric networks across the operating frequency range are less than variations in amplitude of a signal propagated through only the acoustic resonance cavity and the two acoustic transducers. an acoustic resonance cavity through which a fluid can flow, the fluid having a temperature within an operating temperature range, the acoustic resonance cavity capable of supporting an acoustic standing wave, wherein the frequency of the acoustic standing wave varies with the temperature of the fluid over the operating temperature range, thereby defining an operating frequency range; at least two acoustic transducers, respectively for generating and detecting the acoustic standing wave, wherein a frequency response of said transducers varies over said operating frequency range; characterised in that it further comprises an electric network connected to each transducer, said electric network comprising at least one inductive and at least one capacitive component; wherein the at least one inductive and at least one capacitive component define, together with the connected transducer, a resonance behaviour in which signals in a part of the operating frequency range in which the transducer has a first sensitivity are preferentially amplified relative to signals in a part of the operating frequency range in which the transducer has a second sensitivity, wherein the first sensitivity is lower than the second sensitivity, so that variations in the amplitude of signals propagated through the acoustic resonance cavity, the two acoustic transducers and the connected electric networks across the operating frequency range are less than variations in amplitude of a signal propagated through only the acoustic resonance cavity and the two acoustic transducers. <EOS>