Selected Factors Affecting Uncertainty of All-Weather Microphones Research

• Autorzy: Wszołek G.
• Języki publikacji: EN

Abstrakty

EN

Testing of devices for acoustic measurements in a free-field are being performed at the stage of designing and type certification. Free-field tests are performed only in a few laboratories – mainly in National Metrology Institutes. These are: Danish Primary Laboratory of Acoustics (DPLA, Denmark), Physikalisch Technische Bundesanstalt in Braunschweig (PTB, Germany), National Physical Laboratory (NPL, United Kingdom) National Institute of Standards and Technology (NIST, United States of America). The Vibroacoustic Laboratory of the Department of Mechanics and Vibroacoustics, AGH is the only place in Poland where this type of tests is performed. This is calibration laboratory, which has an accreditation of Polish Centre for Accreditation (AP 022). Certain factors related to the determination of frequency and directivity responses of all-weather microphones, which have a significant influence on the uncertainty of the obtained results – are presented in the paper. The response values, given below, indicate the calibration accuracy. This accuracy is necessary since the aim of the measurements is to determine corrections and designing of the proper compensating filters, which will allow to eliminate any influence of devices on the acoustic field, the parameters of which are actually under testing. This is directly related to the uncertainty assessment of environmental measurements (e.g. to the accuracy of acoustic maps). The necessity of collaboration of laboratories performing such tests and the need of inter-laboratory comparisons is pointed out in the present paper. The unification of the method of testing and the assessment of the uncertainty of results seems to be necessary.

Słowa kluczowe

EN

all-weather microphones; free-field investigation; frequency responses; directional responses; interlaboratory comparisons

• Wydawca: Instytut Podstawowych Problemów Techniki PAN ; Komitet Akustyki PAN ; Polskie Towarzystwo Akustyczne
• Czasopismo: Archives of Acoustics
• Rocznik: 2009
• Tom: Vol. 34, No. 4
• Strony: 547--557
• Opis fizyczny: Bibliogr. 14 poz., fot., tab., wykr.

Twórcy

autor

Wszołek G.

• AGH University of Science and Technology Department of Mechanics and Vibroacoustics Al. Mickiewicza 30, 30-059 Kraków, Poland,

Bibliografia

• [1] IEC 61094: Measurement microphones - Part: 1, 2, 3, 4, 5, 6.
• [2] IEC 61672: Electroacoustics - Sound level meters, Part 1: Specifications, Part 2: Pattern evaluation tests, Part 3 Periodic test.
• [3] Wszołek G., All-weather Microphones [in Polish], XII Scientific Conference of Vibrotechnique ans Vibroacoustics, VII All-Poland Seminar Vibroacoustics in Technical Systems, WIBROTECH 2006, Kraków 28-29.09.2006, pp. 150-151, CD; Wszolek_G.pdf, 6 pages.
• [4] Wszołek G., Wszołek W., All-weather Microphones in Monitoring Systems [in Polish], Proceedings of XXXV Winter School of Vibroacoustic Hazards Control, pp. 195-200, Gliwice - Ustron 26.02-2.03.2007.
• [5] Wszołek G., Barwicz W., Comparative Calibrations of Measuring Microphones Performed in a Free Field, Archives of Acoustics, 32, 4 (Supplement), 305-312 (2007).
• [6] Wszołek G., Barwicz W., Bilateral comparison of the sound level meter calibration in the free-field, Proceedings of XXXVI Winter School of Vibroacoustic Hazards Control, pp. 177-181, Gliwice - Wisła 25-29.02.2008.
• [7] Wszołek G., Engel Z., Investigations of uncertainty of acoustical measuring instruments applied to noise control, Archives of Acoustics, 29, 2, 283-295 (2004).
• [8] Wszołek G., Barwicz W., Duminov S., Automatic Measuring System for Acoustical Devices Calibration in the Free-Field, Archives of Acoustics, 31, 4, 397-402 (2006).
• [9] Internet pages of Norsonic Company-www.norsonic.com.
• [10] Frederiksen E., Gramtorp J., Measurement of Microphone Free-Field corrections and Determination of their Uncertanities, 15th International Congress on Acoustics, 26-30 June, Trondheim, Norway 1995.
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• [12] Barrera-Figueroa S., An experimental study of free-field reciprocity calibration of condenser microphones, Proccedings of nternational Congress on Sound and Vibration, ICSV9, Orlando, July 2002, Paper ID 273.
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