The 10 volt fixed frequency Josephson voltage standard at UME-Ulusal Metroloji Enstitusu

Selçik, S.; Akyel, B.; Gutmann, P.

doi:10.1109/cpem.1998.700053

Cited by 1 publication

(3 citation statements)

References 3 publications

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“…The global value result for the theoretical calculation of the measurement uncertainty related to audiometer calibration was within the expected range. This result is in very good agreement with the results presented by the Eletroacoustical Laboratory (LAETA/INMETRO, Brazil) [1] and the National Metrology Institute of Turkey [4]. The range of these uncertainty values was ±0.3 dB to ±0.6 dB.…”

Section: Introductionsupporting

confidence: 91%

“…The standard IEC 60645-1 (2001 edition) [4] establishes the U max for SPL at 125 Hz to 4 kHz as ±0.7 dB and over 4 kHz as ±1.2 dB.…”

Section: Discussionmentioning

confidence: 99%

“…In order to get accreditation from INMETRO it will be necessary to improve the calibration process such that it allows the expanded uncertainty to be equal to or lower than ±0.7 dB. In this way the laboratory will comply with the standard IEC 60645-1 [4]. Some of the uncertainty sources were discarded in this study.…”

Section: Discussionmentioning

confidence: 99%

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Uncertainty in audiometer calibration

2003

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The objective of this work is to present a metrology study necessary for the accreditation of audiometer calibration procedures at the National Brazilian Institute of Metrology Standardization and Industrial Quality-INMETRO. A model for the calculation of measurement uncertainty was developed. Metrological aspects relating to audiometer calibration, traceability and measurement uncertainty were quantified through comparison between results obtained at the Industrial Noise Laboratory-LARI of the Federal University of Santa Catarina-UFSC and the Laboratory of Electric/acoustics-LAETA of INMETRO. Similar metrological performance of the measurement system used in both laboratories was obtained, indicating that the interlaboratory results are compatible with the expected values. The uncertainty calculation was based on the documents: EA-4/02 Expression of the Uncertainty of Measurement in Calibration (European Co-operation for Accreditation 1999 EA-4/02 p 79) and Guide to the Expression of Uncertainty in Measurement (International Organization for Standardization 1993 1st edn, corrected and reprinted in 1995, Geneva, Switzerland). Some sources of uncertainty were calculated theoretically (uncertainty type B) and other sources were measured experimentally (uncertainty type A). The global value of uncertainty calculated for the sound pressure levels (SPLs) is similar to that given by other calibration institutions. The results of uncertainty related to measurements of SPL were compared with the maximum uncertainties U max given in the standard

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Section: Introductionsupporting

confidence: 91%

“…The standard IEC 60645-1 (2001 edition) [4] establishes the U max for SPL at 125 Hz to 4 kHz as ±0.7 dB and over 4 kHz as ±1.2 dB.…”

Section: Discussionmentioning

confidence: 99%