Date of Award
Open Access Master's Report
Master of Science in Mechanical Engineering (MS)
Administrative Home Department
Department of Mechanical Engineering-Engineering Mechanics
Committee Member 1
Committee Member 2
The theory of sound intensity measurement using the two-microphone method was first developed in the late 1970s. Even though the measurements were limited by the technology of the time, the theory was straight-forward and considerable attention was given to improving precision during testing or post-processing. With the development of modern equipment, however, the focus shifted to the apparatus. The commercial intensity probes available today have microphones that are already phase-matched. This eliminates the need for correction during or post-testing as a majority of the errors are minimized before any data is even collected. Although such intensity probes facilitate taking precise measurements, they have a major drawback – cost. Additionally, not only are phase-matched microphones expensive to manufacture but they are also hard to replace.
This report explores an intensity measurement technique that enables the use of current, inexpensive equipment along with a custom LabVIEW code. Phase and amplitudes are corrected using dedicated, handheld calibrators. The phase calibrator and the intensity probe are manufactured using in-house rapid prototyping to bring down the cost. Custom LabVIEW code is developed that calculates sound intensity while dealing with phase mismatch between the two relatively inexpensive microphones. Furthermore, the custom intensity probe is compared with a commercially available probe and the measurement readings are discussed.
Gundre, Karan, "Comparative Study and Design of Economical Sound Intensity Probe", Open Access Master's Report, Michigan Technological University, 2019.