Garg, N. and Surendran, P. and Dhanya, M. P. and Chandran, A. T. and Asif, M. and Singh, M (2019) Measurement Uncertainty in Microphone Free-Field Comparison Calibrations. Mapan, 24 (3 (SI)). 357-369. ISSN 0970-3950
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Abstract
The present study demonstrates the use of a transportable anechoic chamber for conducting microphone free-field calibrations with lowest levels of uncertainty. A dedicated transportable anechoic chamber (make SPEKTRA, Germany) of internal volume of 2 m(3) completely lined with wedge-shaped absorbers is utilized for free-field calibrations in the frequency range of 125 Hz-20 kHz using the substitution method as per the IEC 61094-8 standard. The study has identified the usable working space inside a free-field chamber using the inverse-square pressure law, and the deviations from the inverse-square law of the free-field chamber are quantified. The measurement uncertainty of +/- 0.36-0.52 dB (k = 2, 95% confidence level) is evaluated in the frequency range of 125 Hz-20 kHz and is validated in a bilateral comparison. The application of Monte Carlo simulation approach in the evaluation of measurement uncertainty in microphone free-field calibrations is also demonstrated.
| Item Type: | Article |
|---|---|
| Additional Information: | Copyright for this article belongs to M/s Springer Verlag |
| Subjects: | Instruments/ Instrumentation Applied Physics/Condensed Matter |
| Divisions: | UNSPECIFIED |
| Depositing User: | Mr. Yogesh Joshi |
| Date Deposited: | 19 Aug 2026 11:25 |
| Last Modified: | 19 Aug 2026 11:25 |
| URI: | https://npl.csircentral.net/id/eprint/4308 |
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