Development of an acoustic flowmeter for low flow rates

Abstract

The use of non-intrusive acoustic flow meters for residential applications has been little explored. This work presents the development of a non-intrusive acoustic instrument for low water flow rates measured at a PVC pipe knee. A chest piece of stethoscope with an electret microphone was used, and 10 collection cycles were performed, in a range of 16–488 L/h (lph). The results show that there is a quadratic relationship between the standard deviation of the acoustic signal and the water flow, and the existence of a transition region is predicted. Furthermore, there was an exponential relationship between the standard deviation of the detail coefficients of the Wavelet Transform and the energy of the approximation coefficients with the fluidic flow. Thus, as far as we know, this is the first time that a correlation between the acoustic noise generated by a low flow of water on a residential scale is presented. This approach represents a potential alternative for monitoring water consumption at specific points in a residence, which, in turn, enables the identification of user patterns and contributes to the management of the distribution of water resources in a given location.