New Measurement Service for Determining Pressure Sensitivity of Type LS2aP Microphones by the Reciprocity Method

Published

October 1, 2011

Author(s)

Randall P. Wagner, Victor Nedzelnitsky, Steven E. Fick

Abstract

A new NIST measurement service has been developed for determining the pressure sensitivities of American National Standards Institute and International Electrotechnical Commission type LS2aP laboratory standard microphones over the frequency range 31.5 Hz to 20 000 Hz. At most frequencies common to the new service and the old service, the values of the expanded uncertainties of the new service are one-half the corresponding values of the old service, or better. The new service uses an improved version of the system employed by NIST in the Consultative Committee for Acoustics, Ultrasound, and Vibration (CCAUV) key comparison CCAUV.A-K3. Measurements are performed using a long and a short air-filled plane-wave coupler. For each frequency in the range 31.5 Hz to 2000 Hz, the reported sensitivity level is the average of data from both couplers. For each frequency above 2000 Hz, the reported sensitivity level is determined with data from the short coupler only. For proof test data in the frequency range 31.5 Hz to 2000 Hz, the average absolute differences between data from the long and the short couplers are much smaller than the expanded uncertainties.

Citation

Journal of Research (NIST JRES) -

Volume

116

Issue

5

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

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Keywords

acoustic measurements, acoustical calibration, calibration of microphones, electroacoustics, laboratory standard microphone, measuring microphone, microphone calibration, microphone pressure calibration, microphone reciprocity calibration, pressure reciprocity calibration of microphones, reciprocity calibration, standard microphones

Citation

Wagner, R. , Nedzelnitsky, V. and Fick, S. (2011), New Measurement Service for Determining Pressure Sensitivity of Type LS2aP Microphones by the Reciprocity Method, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908243 (Accessed November 21, 2024)