Design and development of a low-cost non-intrusive passive acoustic sensor

Abstract

In this paper, we report on the development and performance study of a low-cost non-intrusive passive acoustic sensor (NIPAS), suitable for gas flow rate measurement and monitoring in pipelines and other similar applications. Detailed information on the design considerations, development, construction, and assembly of the sensor and its unit are also provided in this paper. The complete NIPAS unit is made up of two sensor heads fixed at the test section of a designed flow loop to receive the acoustic emission signals generated from the varying gas flow rate and processed by a control unit for data collection and analysis. The electronic unit was enclosed in a Perspex casing for easy interfacing and protection. Observations on the performance of the developed NIPAS are presented as a voltage-time signal and analyzed in both time and frequency domains. Calibration of the NIPAS was done using suitable statistical features, which are the mean, standard deviation, and coefficient of variation of the signals. Results obtained indicate that the developed NIPAS unit shows proof of concept and it is suitable for measuring and monitoring gas flow rates in pipes.