Comparison Display

CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 250 Hz

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2) expressed in
dB re 1 V/Pa

Click on the graph below to get a closer view

Red diamonds: participants in CCAUV.A-K3
Green triangles: participants in COOMET.AUV.A-K3
Blue squares: participants in EUROMET.AUV.A-K3
Orange circle: participant in APMP.AUV.A-K3.1
Pink squares: participants in APMP.AUV.A-K3

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 1000 Hz

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2) expressed in
dB re 1 V/Pa

Click on the graph below to get a closer view

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 31.5 Hz to 31.5 kHz

Graphs of equivalence are provided for frequencies 250 Hz and 1000 Hz only

Frequency 250 Hz: Click on the graph below to get a closer view

FREQUENCY : 1000 Hz : Click on the graph below to get a closer view

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 250 Hz

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2)

Black: participants in CCAUV.A-K3
Green: participants in COOMET.AUV.A-K3
Blue: participants in EUROMET.AUV.A-K3
Orange: participant in APMP.AUV.A-K3.1
Pink: participants in APMP.AUV.A-K3


Lab i	D_i	U_i
	/ dB	/ dB
CENAM	0.014	0.052
NMIA	0.004	0.035
DPLA	-0.004	0.025
GUM	-0.016	0.045
INMETRO	0.001	0.040
KRISS	0.008	0.026
LNE	0.016	0.026
NIM	-0.009	0.045
NIST	-0.001	0.035
NMIJ	-0.016	0.082
NPL	-0.006	0.026
NRC	-0.006	0.035
PTB	0.004	0.035
UME	0.007	0.073
VNIIFTRI	-0.016	0.035
NPLI	0.015	0.073
GUM*	-0.010	0.049
DNDI "Systema"*	-0.040	0.067
VNIIFTRI*	0.052	0.039
INM(RO)*	0.018	0.044

* indicates participants in COOMET.AUV.A-K3
The pair-wise degrees of equivalence obtained inside EUROMET.AUV.A-K3 are available by clicking here.
The pair-wise degrees of equivalence obtained inside APMP.AUV.A-K3 are available in Table 11d, page 41 of the APMP.AUV.A-K3 Final Report.

These results are presented under A4 printable format in Summary Results (PDF file).

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 1000 Hz

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2)

Black: participants in CCAUV.A-K3
Green: participants in COOMET.AUV.A-K3
Blue: participants in EUROMET.AUV.A-K3
Orange: participant in APMP.AUV.A-K3.1
Pink: participants in APMP.AUV.A-K3


Lab i	D_i	U_i
	/ dB	/ dB
CENAM	0.013	0.052
NMIA	0.002	0.035
DPLA	-0.004	0.025
GUM	-0.017	0.045
INMETRO	0.000	0.040
KRISS	0.008	0.026
LNE	0.013	0.027
NIM	-0.010	0.045
NIST	-0.004	0.035
NMIJ	-0.027	0.082
NPL	0.003	0.026
NRC	-0.008	0.035
PTB	0.003	0.035
UME	0.006	0.073
VNIIFTRI	-0.013	0.035
NPLI	0.005	0.073
GUM*	-0.004	0.049
DNDI "Systema"*	-0.034	0.058
VNIIFTRI*	0.050	0.039
INM(RO)*	0.018	0.044

These results are presented under A4 printable format in Summary Results (PDF file).

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3, and APMP.AUV.A-K3.1

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 31.5 Hz to 31.5 kHz

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2) expressed in
dB re 1 V/Pa

In green : participants in COOMET.AUV.A-K3
In blue : participants in EUROMET.AUV.A-K3
In orange : participant in APMP.AUV.A-K3.1

Results are presented under A4 printable format in Summary Results (PDF file).

Graphs of equivalence for 250 Hz and 1000 Hz are also extended with APMP.AUV.A-K3 results.

Pair-wise degrees of equivalence are computed for frequencies 250 Hz and 1000 Hz only, for participants in CCAUV.A-K3, EUROMET.AUV.A-K3 and COOMET.AUV.A-K3.

CCAUV.A-K3

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Information & contact
Participants

Metrology area, Sub-field	Acoustics, Ultrasound, Vibration, Acoustics
Description	Comparison of laboratory standard microphone calibrations
Time of measurements	2003
Status	Approved for equivalence

Final Reports of the comparisons	Metrologia, 2006, 43, Tech. Suppl., 09001 Metrologia, 2007, 44, Tech. Suppl., 09005
Measurand	Sound pressure
Parameters	Frequency: 31.5 Hz to 31.5 kHz
Transfer device	Four LS2P microphones

Comparison type	Key Comparison
Consultative Committee	CCAUV (Consultative Committee for Acoustics, Ultrasound and Vibration)
Conducted by	CCAUV (Consultative Committee for Acoustics, Ultrasound and Vibration)
Comments	PTB acting as COOMET member CCAUV.A-K3 results published on 09 June 2006, and completed with the bilateral extension DPLA-NPLI on 07 September 2007 COOMET.AUV.A-K3, EUROMET.AUV.A-K3, APMP.AUV.A-K3.1 and APMP.AUV.A-K3 results are linked to those of CCAUV.A-K3 Laboratory standard microphones LS2P
Pilot institute	CENAM Centro Nacional de Metrologia Mexico
Contact person	S. Echeverria-Gomez +52 442 11 0550
Additional	K. Rasmussen, Danish Fundamental Metrology A/S V. Cutanda Henriquez, Centro Nacional de Metrologia

Pilot laboratory
CENAM	Centro Nacional de Metrologia, Mexico, SIM

GUM	Glowny Urzad Miar, Central Office of Measures, Poland, EURAMET

INMETRO

Instituto Nacional de Metrologia, Qualidade e Tecnologia, Brazil, SIM

KRISS

Korea Research Institute of Standards and Science, Korea, Republic of, APMP

LNE	Laboratoire national de métrologie et d'essais, France, EURAMET

NIM	National Institute of Metrology, China, APMP

NIST	National Institute of Standards and Technology, United States, SIM

NMIA	National Measurement Institute, Australia, Australia, APMP

NMIJ AIST

National Metrology Institute of Japan, Japan, APMP

NPL	National Physical Laboratory, United Kingdom, EURAMET

NPLI	CSIR National Physical Laboratory of India, India, APMP

NRC	National Research Council, Canada, SIM

PTB	Physikalisch-Technische Bundesanstalt, Germany, EURAMET

UME	TÜBITAK Ulusal Metroloji Enstitüsü, Türkiye, EURAMET

VNIIFTRI

Institute of Physical Technical and Radiotechnical Measurements, Rosstandart, Russian Federation, COOMET

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

Key comparison CCAUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 250 kHz

For each microphone, the key comparison reference value, x_R, and its associated standard uncertainty, u_R, are computed as explained in sections 4.2 and 5.1 of the CCAUV.A-K3 Final Report (unit is dB re 1 V/Pa).

The degree of equivalence of laboratory i with respect to the reference value is given by a pair of terms expressed in dB re 1 V/Pa:
D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in sections 4.3 and 5.2 of the CCAUV.A-K3 Final Report, and in the Final Report of the bilateral comparison DPLA-NPLI.

The degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij and U_ij, its expanded uncertainty (k = 2), both expressed in dB re 1 V/Pa. The computation of these two terms is explained in section 5.3 of the CCAUV.A-K3 Final Report, and in the Final Report of the bilateral comparison DPLA-NPLI.

Linking COOMET.AUV.A-K3 to CCAUV.A-K3

DPLA provides the link between key comparisons CCAUV.A-K3 and COOMET.AUV.A-K3. The linkage process is described in section 5 of the COOMET.AUV.A-K3 Final Report.

The degree of equivalence of laboratory i participant in COOMET.AUV.A-K3 with respect to the key comparison reference value is given by a pair of terms expressed in dB re 1 V/Pa: D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in section 5 of the COOMET.AUV.A-K3 Final Report.

Linking EUROMET.AUV.A-K3 to CCAUV.A-K3

DPLA provides the link between key comparisons CCAUV.A-K3 and EUROMET.AUV.A-K3. The linkage process is described in section 6 of the EUROMET.AUV.A-K3 Final Report.

The degree of equivalence of laboratory i participant in EUROMET.AUV.A-K3 with respect to the key comparison reference value is given by a pair of terms expressed in dB re 1 V/Pa: D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in section 6 of the EUROMET.AUV.A-K3 Final Report.

The degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij and U_ij, its expanded uncertainty (k = 2), both expressed in dB re 1 V/Pa.
The computation of these two terms is explained in section 7 of the EUROMET.AUV.A-K3 Final Report when both of the laboratories are participants in EUROMET.AUV.A-K3.

The matrix of equivalence computed from CCAUV.A-K3 and COOMET.AUV.A-K3 is expanded with pair-wise degrees of equivalence obtained inside EUROMET.AUV.A-K3.

Linking APMP.AUV.A-K3.1 to CCAUV.A-K3

KRISS provides the link between key comparisons CCAUV.A-K3 and APMP.AUV.A-K3.1. The linkage process is described in section 8 of the APMP.AUV.A-K3.1 Final Report.

The degree of equivalence of KIM-LIPI participant in APMP.AUV.A-K3.1 with respect to the key comparison reference value is given by a pair of terms expressed in dB re 1 V/Pa: D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in section 8 of the APMP.AUV.A-K3.1 Final Report.

No pair-wise degrees of equivalence between KIM-LIPI and other participants in CCAUV.A-K3 have been computed.

Linking APMP.AUV.A-K3 to CCAUV.A-K3

NMIJ, KRISS, NIM, and NMIA provide the link between key comparisons CCAUV.A-K3 and APMP.AUV.A-K3. The linkage process is described in section 6 of the APMP.AUV.A-K3 Final Report.

The degree of equivalence of laboratory i participant in APMP.AUV.A-K3 with respect to the key comparison reference value is given by a pair of terms expressed in dB re 1 V/Pa: D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in section 6 of the APMP.AUV.A-K3 Final Report.

The degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij and U_ij, its expanded uncertainty (k = 2), both expressed in dB re 1 V/Pa.
The computation of these two terms is explained in section 7 of the APMP.AUV.A-K3 Final Report when both of the laboratories are participants in APMP.AUV.A-K3, and the numerical values can be found from Table 11a to 11p in the APMP.AUV.A-K3 Final Report.

This makes it possible to extend the graphs of equivalence of the participants in CCAUV.A-K3 with the participants in APMP.AUV.A-K3 for frequency 250 Hz.

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

Key comparison CCAUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 1000 Hz

Linking COOMET.AUV.A-K3 to CCAUV.A-K3

DPLA provides the link between key comparisons CCAUV.A-K3 and COOMET.AUV.A-K3. The linkage process is described in section 5 of the COOMET.AUV.A-K3 Final Report.

Linking EUROMET.AUV.A-K3 to CCAUV.A-K3

DPLA provides the link between key comparisons CCAUV.A-K3 and EUROMET.AUV.A-K3. The linkage process is described in section 6 of the EUROMET.AUV.A-K3 Final Report.

Linking APMP.AUV.A-K3.1 to CCAUV.A-K3

KRISS provides the link between key comparisons CCAUV.A-K3 and APMP.AUV.A-K3.1. The linkage process is described in section 8 of the APMP.AUV.A-K3.1 Final Report.

No pair-wise degrees of equivalence between KIM-LIPI and other participants in CCAUV.A-K3 have been computed.

Linking APMP.AUV.A-K3 to CCAUV.A-K3

NMIJ, KRISS, NIM, and NMIA provide the link between key comparisons CCAUV.A-K3 and APMP.AUV.A-K3. The linkage process is described in section 6 of the APMP.AUV.A-K3 Final Report.

The degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij and U_ij, its expanded uncertainty (k = 2), both expressed in dB re 1 V/Pa.
The computation of these two terms is explained in section 7 of the APMP.AUV.A-K3 Final Report when both of the laboratories are participants in APMP.AUV.A-K3, and the numerical values can be found from Table 11a to 11p in the APMP.AUV.A-K3 Final Report.

This makes it possible to extend the graphs of equivalence of the participants in CCAUV.A-K3 with the participants in APMP.AUV.A-K3 for frequency 1000 Hz.

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3, and APMP.AUV.A-K3.1

Key comparison CCAUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 31.5 Hz to 31.5 kHz

For each microphone and for each frequency, the key comparison reference value, x_R, and its associated standard uncertainty, u_R, are computed as explained in sections 4.2 and 5.1 of the CCAUV.A-K3 Final Report (unit is dB re 1 V/Pa).

At a given frequency, the degree of equivalence of laboratory i with respect to the reference value is given by a pair of terms expressed in dB re 1 V/Pa:
D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in sections 4.3 and 5.2 of the CCAUV.A-K3 Final Report, and in the Final Report of the bilateral comparison DPLA-NPLI.

Graphs of equivalence are given for frequencies 250 Hz and 1000 Hz only.

At a given frequency, the degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij and U_ij, its expanded uncertainty (k = 2), both expressed in dB re 1 V/Pa. The computation of these two terms is explained in section 5.3 of the CCAUV.A-K3 Final Report, and in the Final Report of the bilateral comparison DPLA-NPLI.
The full matrices of equivalence are computed for frequencies 250 Hz and 1000 Hz.

Linking COOMET.AUV.A-K3 to CCAUV.A-K3

DPLA provides the link between key comparisons CCAUV.A-K3 and COOMET.AUV.A-K3. The linkage process is described in section 5 of the COOMET.AUV.A-K3 Final Report.

At a given frequency, the degree of equivalence of laboratory i participant in COOMET.AUV.A-K3 with respect to the key comparison reference value is given by a pair of terms expressed in dB re 1 V/Pa:
D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in section 5 of the COOMET.AUV.A-K3 Final Report.

Full graphs of equivalence are given for frequencies 250 Hz and 1000 Hz only.

At a given frequency, the degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij and U_ij, its expanded uncertainty (k = 2), both expressed in dB re 1 V/Pa.
The computation of these two terms is explained in section 5 of the COOMET.AUV.A-K3 Final Report when one or two laboratories participate in COOMET.AUV.A-K3.

The full matrices of equivalence are computed for frequency 250 Hz and 1000 Hz only.

Linking EUROMET.AUV.A-K3 to CCAUV.A-K3

DPLA provides the link between key comparisons CCAUV.A-K3 and EUROMET.AUV.A-K3. The linkage process is described in section 6 of the EUROMET.AUV.A-K3 Final Report.

At a given frequency, the degree of equivalence of laboratory i participant in EUROMET.AUV.A-K3 with respect to the key comparison reference value is given by a pair of terms expressed in dB re 1 V/Pa:
D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in section 6 of the EUROMET.AUV.A-K3 Final Report.

Full graphs of equivalence are given for frequencies 250 Hz and 1000 Hz only.

At a given frequency, the degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij and U_ij, its expanded uncertainty (k = 2), both expressed in dB re 1 V/Pa.
The computation of these two terms is explained in section 7 of the EUROMET.AUV.A-K3 Final Report when both of the laboratories are participants in EUROMET.AUV.A-K3.

The matrices of equivalence computed from CCAUV.A-K3 and COOMET.AUV.A-K3 for frequencies 250 Hz and 1000 Hz are expanded with pair-wise degrees of equivalence obtained inside EUROMET.AUV.A-K3.

Linking APMP.AUV.A-K3.1 to CCAUV.A-K3

FREQUENCY : 31.5 Hz to 25 kHz

KRISS provides the link between key comparisons CCAUV.A-K3 and APMP.AUV.A-K3.1. The linkage process is described in section 8 of the APMP.AUV.A-K3.1 Final Report.

At a given frequency the degree of equivalence of KIM-LIPI participant in APMP.AUV.A-K3.1 with respect to the key comparison reference value is given by a pair of terms expressed in dB re 1 V/Pa: D_i and U_i, its expanded uncertainty (k = 2). The degrees of equivalence are computed as explained in section 8 of the APMP.AUV.A-K3.1 Final Report

Full graphs of equivalence are given for frequencies 250 Hz and 1000 Hz only.

No pair-wise degrees of equivalence between KIM-LIPI and other participants in CCAUV.A-K3 have been computed.

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

Key comparison CCAUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 250 Hz

x_i : result of measurements carried out by laboratory i (unit is dB re 1 V/Pa)
Results from LNE, NIM and INMETRO have been corrected for nominal frequencies as described in section 3.2 of the Final Report.

u_i : combined standard uncertainty of x_i

Microphone: 1395456

Lab i x_i
/ dB 2u_i/ dB

CENAM -38.43 0.06

DPLA -38.459 0.03

GUM -38.46 0.05

KRISS -38.441 0.03

LNE -38.436 0.030

NIST -38.454 0.04

NMIJ -38.47 0.09

NPL -38.46 0.03

PTB -38.45 0.04

Microphone: 1627783

Lab i x_i
/ dB 2u_i/ dB

CENAM -38.76 0.06

DPLA -38.771 0.03

GUM -38.79 0.05

KRISS -38.760 0.03

LNE -38.750 0.030

NIST -38.765 0.04

NMIJ -38.78 0.09

NPL -38.77 0.03

PTB -38.76 0.04

Microphone: 1124046

Lab i	x_i / dB	2u_i/ dB

CENAM	-38.076	0.06
NMIA	-38.10	0.04
DPLA	-38.103	0.03
INMETRO	-38.103	0.045
NIM	-38.112	0.05
NRC	-38.109	0.04
UME	-38.098	0.08
VNIIFTRI	-38.12	0.04
DPLA*	-38.114	0.03
NPLI*	-38.100	0.10

Microphone: 1395455

Lab i	x_i / dB	2u_i/ dB

CENAM	-38.404	0.06
NMIA	-38.40	0.04
DPLA	-38.409	0.03
INMETRO	-38.404	0.045
NIM	-38.414	0.05
NRC	-38.411	0.04
UME	-38.397	0.08
VNIIFTRI	-38.42	0.04
DPLA*	-38.403

0.03

NPLI*

-38.380

0.10

*participants in the bilateral comparison DPLA-NPLI, conducted as an extension of key comparison CCAUV.A-K3

Key comparison COOMET.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 250 Hz

x_i-COO : result of measurements carried out by laboratory i participant in the key comparison COOMET.AUV.A-K3; unit is dB re 1 V/Pa

u_i-COO : combined standard uncertainty of x_i-COO

A sudden change in sensitivity of microphone 1503926 occured during the comparison.

Microphone: 1503926 (before change in sensitivity)

Lab i
x_i-COO
/ dB 2u_i-COO/ dB

DPLA -38.918 0.03

GUM -38.920 0.05

DNDI "Systema" -38.950 0.07

Microphone: 1503926 (after change in sensitivity)

Lab i
x_i-COO
/ dB 2u_i-COO/ dB

DPLA -38.851 0.03

VNIIFTRI -38.812 0.04

INM(RO) -38.843 0.046

Microphone: 1503933

Lab i x_i-COO
/ dB 2u_{i -COO}/ dB

DPLA -38.960 0.03

GUM -38.97 0.05

DNDI "Systema" -39.00 0.07

VNIIFTRI -38.882 0.04

INM(RO) -38.938 0.046

Microphone: 1526170

Lab i x_i-COO
/ dB 2u_i-COO/ dB

DPLA -38.855 0.03

VNIIFTRI -38.807 0.04

INM(RO) -38.820 0.046

Key comparison EUROMET.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 250 Hz

x_i-EUR : result of measurements carried out by laboratory i participant in the key comparison EUROMET.AUV.A-K3; unit is dB re 1 V/Pa

u_i-EUR : combined standard uncertainty of x_i-EUR

Microphone: 1395456

Lab i x_i-EUR
/ dB 2u_i-EUR/ dB

DPLA -38.450 0.03

INRIM -38.430 0.05

BEV -38.434 0.02

CMI -38.480 0.06

METAS -38.430 0.036

CEM -38.449 0.04

MIKES -38.431 0.0259

SP -38.429 0.05

Microphone: 1627783

Lab i x_i-EUR
/ dB 2u_i-EUR/ dB

DPLA -38.767 0.03

INRIM -38.740 0.05

BEV -38.763 0.02

CMI -38.810 0.06

METAS -38.743 0.036

CEM -38.782 0.04

MIKES -38.760 0.0258

SP -38.744 0.05

Lab i
Date of measurement

DPLA 15 Oct 03

INRIM 05 Nov 03

BEV 20 Nov 03

CMI 03 Dec 03

METAS 15 Jan 04

CEM 01 Mar 04

MIKES 29 Mar 04

SP 28 Apr 04

CMI, METAS, and CEM data were corrected for frequency realignment to nominal frequencies.
SP and MIKES data were corrected for microphone 1395456 sensitivity drift.

Key comparison APMP.AUV.A-K3.1

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 250 Hz

x_i-APMP(K3.1) : result of measurements carried out by laboratory i participant in the key comparison APMP.AUV.A-K3.1; unit is dB re 1 V/Pa

U_i_-APMP(K3.1) : expanded uncertainty (k = 2) of x_i-APMP(K3.1)

Microphone: 2341431

Lab i
x_i_-APMP(K3.1)/ dB
U_i_-APMP(K3.1)/ dB

KRISS -38.74 0.04

KIM-LIPI -38.75 0.06

Key comparison APMP.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P

FREQUENCY : 250 Hz

x_i_-APMP(K3): result of measurements carried out by laboratory i participant in the key comparison APMP.AUV.A-K3; unit is dB re 1 V/Pa
U_i_-APMP(K3) : expanded uncertainty (k = 2) of x_i_-APMP(K3)

Microphone: 1763688

The measurement results reported by the participants can be found in Table 2a and 3 of the APMP.AUV.A-K3 Final Report.

Microphone: 2341431

The measurement results reported by the participants can be found in Table 2b and 3 of the APMP.AUV.A-K3 Final Report.

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3,
APMP.AUV.A-K3.1, and APMP.AUV.A-K3

Key comparison CCAUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 1000 Hz

u_i : combined standard uncertainty of x_i

Microphone: 1395456

Lab i x_i
/ dB 2u_i/ dB

CENAM -38.46 0.06

DPLA -38.489 0.03

GUM -38.49 0.05

KRISS -38.471 0.03

LNE -38.468 0.031

NIST -38.488 0.04

NMIJ -38.51 0.09

NPL -38.48 0.03

PTB -38.48 0.04

Microphone: 1627783

Lab i x_i
/ dB 2u_i/ dB

CENAM -38.77 0.06

DPLA -38.780 0.03

GUM -38.80 0.05

KRISS -38.769 0.03

LNE -38.762 0.031

NIST -38.777 0.04

NMIJ -38.80 0.09

NPL -38.77 0.03

PTB -38.77 0.04

Microphone: 1124046

Lab i	x_i / dB	2u_i/ dB

CENAM	-38.082	0.06
NMIA	-38.11	0.04
DPLA	-38.107	0.03
INMETRO	-38.108	0.045
NIM	-38.118	0.05
NRC	-38.116	0.04
UME	-38.104	0.08
VNIIFTRI	-38.12	0.04
DPLA*

-38.116

0.03

NPLI*

-38.110

0.10

Microphone: 1395455

Lab i	x_i / dB	2u_i/ dB

CENAM	-38.415	0.06
NMIA	-38.41	0.04
DPLA	-38.419	0.03
INMETRO	-38.415	0.045
NIM	-38.426	0.05
NRC	-38.423	0.04
UME	-38.408	0.08
VNIIFTRI	-38.43	0.04
DPLA*	-38.412	0.03
NPLI*	-38.400	0.10

*participants in the bilateral comparison DPLA-NPLI, conducted as an extension of key comparison CCAUV.A-K3

Key comparison COOMET.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 1000 Hz

x_i-COO : result of measurements carried out by laboratory i participant in the key comparison COOMET.AUV.A-K3; unit is dB re 1 V/Pa

u_i-COO : combined standard uncertainty of x_i-COO

A sudden change in sensitivity of microphone 1503926 occured during the comparison.

Microphone: 1503926 (before change in sensitivity)

Lab i
x_i-COO
/ dB 2u_i-COO/ dB

DPLA -38.925 0.03

GUM -38.920 0.05

DNDI "Systema" -38.950 0.06

Microphone: 1503926 (after change in sensitivity)

Lab i
x_i-COO
/ dB 2u_i-COO/ dB

DPLA -38.860 0.03

VNIIFTRI -38.823 0.04

INM(RO) -38.851 0.046

Microphone: 1503933

Lab i x_i-COO
/ dB 2u_i-COO/ dB

DPLA -38.964 0.03

GUM -38.97 0.05

DNDI "Systema" -39.00 0.06

VNIIFTRI -38.887 0.04

INM(RO) -38.941 0.046

Microphone: 1526170

Lab i x_i-COO
/ dB 2u_i-COO/ dB

DPLA -38.865 0.03

VNIIFTRI -38.819 0.04

INM(RO) -38.832 0.046

Key comparison EUROMET.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 1000 Hz

x_i-EUR : result of measurements carried out by laboratory i participant in the key comparison EUROMET.AUV.A-K3; unit is dB re 1 V/Pa

u_i-EUR : combined standard uncertainty of x_i-EUR

Microphone: 1395456

Lab i x_i-EUR
/ dB 2u_i-EUR/ dB

DPLA -38.482 0.03

INRIM -38.470 0.05

BEV -38.466 0.02

CMI -38.510 0.06

METAS -38.468 0.036

CEM -38.482 0.04

MIKES -38.463 0.03

SP -38.459 0.05

Microphone: 1627783

Lab i x_i-EUR
/ dB 2u_i-EUR/ dB

DPLA -38.775 0.03

INRIM -38.760 0.05

BEV -38.772 0.02

CMI -38.810 0.06

METAS -38.759 0.036

CEM -38.792 0.04

MIKES -38.769 0.03

SP -38.751 0.05

Lab i
Date of measurement

DPLA 15 Oct 03

INRIM 05 Nov 03

BEV 20 Nov 03

CMI 03 Dec 03

METAS 15 Jan 04

CEM 01 Mar 04

MIKES 29 Mar 04

SP 28 Apr 04

CMI, METAS, and CEM data were corrected for frequency realignment to nominal frequencies.
SP and MIKES data were corrected for microphone 1395456 sensitivity drift.

Key comparison APMP.AUV.A-K3.1

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 1000 Hz

x_i-APMP(K3.1) : result of measurements carried out by laboratory i participant in the key comparison APMP.AUV.A-K3.1; unit is dB re 1 V/Pa

U_i_-APMP(K3.1) : expanded uncertainty (k = 2) of x_i-APMP(K3.1)

Microphone: 2341431

Lab i
x_i_-APMP(K3.1)/ dB
U_i_-APMP(K3.1)/ dB

KRISS -38.73 0.04

KIM-LIPI -38.75 0.06

Key comparison APMP.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P

FREQUENCY : 1000 Hz

Microphone: 1763688

The measurement results reported by the participants can be found in Table 2a and 3 of the APMP.AUV.A-K3 Final Report.

Microphone: 2341431

The measurement results reported by the participants can be found in Table 2b and 3 of the APMP.AUV.A-K3 Final Report.

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CCAUV.A-K3, COOMET.AUV.A-K3, EUROMET.AUV.A-K3, and APMP.AUV.A-K3.1

Key comparison CCAUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 31.5 Hz to 31.5 kHz

u_i : combined standard uncertainty of x_i

Click on the following links to access data obtained for the four transfer microphones from 31.5 Hz to 31.5 kHz:

Microphone 1395456
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Microphone 1627783
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Microphone 1124046
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Microphone 1395455
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Key comparison COOMET.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 31.5 Hz to 31.5 kHz

x_i-COO : result of measurements carried out by laboratory i participant in the key comparison COOMET.AUV.A-K3; unit is dB re 1 V/Pa

u_i-COO : combined standard uncertainty of x_i-COO

Click on the following links to access data obtained for the three transfer microphones from 31.5 Hz to 31.5 kHz:
(a sudden change in sensitivity of microphone 1503926 occured during the comparison)

Microphone 1503926 (before and after change in sensitivity)
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Microphone 1503933
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Microphone 1526170
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Key comparison EUROMET.AUV.A-K3

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 31.5 Hz to 31.5 kHz

x_i-EUR : result of measurements carried out by laboratory i participant in the key comparison EUROMET.AUV.A-K3; unit is dB re 1 V/Pa

u_i-EUR : combined standard uncertainty of x_i-EUR

CMI, METAS, and CEM data were corrected for frequency realignment to nominal frequencies.
SP and MIKES data were corrected for microphone 1395456 sensitivity drift.

Click on the following links to access data obtained for the two transfer microphones from 31.5 Hz to 31.5 kHz:

Microphone 1395456
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Microphone 1627783
Results from 31.5 Hz to 4000 Hz and results from 6300 Hz to 31500 Hz

Key comparison APMP.AUV.A-K3.1

MEASURAND : Pressure sensitivity level of laboratory standard microphone type LS2P
FREQUENCY : 31.5 Hz to 25 kHz

x_i-APMP(K3.1) : result of measurements carried out by laboratory i participant in the key comparison APMP.AUV.A-K3.1; unit is dB re 1 V/Pa

u_i-APMP(K3.1) : combined standard uncertainty of x_i-APMP(K3.1)

Click on the following link to access data obtained for the transfer microphone from 31.5 Hz to 25 kHz:

Microphone 2341431
Results from 31.5Hz to 25000 Hz

KCDB

CIPM MRA

CLASSIFICATION OF SERVICES

Lab i	x_i-COO / dB	2u_i-COO/ dB

DPLA	-38.918	0.03
GUM	-38.920	0.05
DNDI "Systema"	-38.950	0.07

Lab i	x_i-COO / dB	2u_{i -COO}/ dB

DPLA	-38.960	0.03
GUM	-38.97	0.05
DNDI "Systema"	-39.00	0.07
VNIIFTRI	-38.882	0.04
INM(RO)	-38.938	0.046

Lab i	x_i-EUR / dB	2u_i-EUR/ dB

DPLA	-38.450	0.03
INRIM	-38.430	0.05
BEV	-38.434	0.02
CMI	-38.480	0.06
METAS	-38.430	0.036
CEM	-38.449	0.04
MIKES	-38.431	0.0259
SP	-38.429	0.05

Lab i	Date of measurement

DPLA	15 Oct 03
INRIM	05 Nov 03
BEV	20 Nov 03
CMI	03 Dec 03
METAS	15 Jan 04
CEM	01 Mar 04
MIKES	29 Mar 04
SP	28 Apr 04

Lab i	x_i_-APMP(K3.1)/ dB	U_i_-APMP(K3.1)/ dB

KRISS	-38.74	0.04
KIM-LIPI	-38.75	0.06

Key and supplementary comparisons - Print out