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CGPM 2003

CCAUV report

President: Dr. Joaquín Valdés (CIPM)

Executive Secretary: Dr. P. Allisy-Roberts (BIPM)

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CCAUV first meeting July 1999

CCAUV second meeting October 2001

CCAUV third meeting October 200228 delegates, 5 observers and 1 guest

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CCAUV

Summary of Comparison Status

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AcousticsCCAUV Key RMO Key RMO Suplement

A-K1 Published APMP K1 Planned SIM Measurements complete

A-K2 Planned COOMET K1 In progress

A-K3 In Progress EUROMET K1 Draft B

A-K4 Planned EUROMET K2, K3 Planned

W-K1 Draft A SIM K1 Draft B

SIM K1 (old) approved

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Ultrasound

CCAUV Key RMO KeyU-K1 Published EUROMET K1 Planned

U-K2 In progress EUROMET K2 Planned

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Vibration

CCAUV Key RMO Key

V-K1 Published APMP K1 Approved (linked results to be published)EUROMET K1 (old) approved

EUROMET K1 In progress

SIM K1 Draft A

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Estimation of the uncertainties.

Stability of the objects circulated.

Reference standard microphonesinvolved.

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Classification of Services in AUV

Document CCAUV 02 - 05

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Future Needs for Metrology in AUV

Report prepared by NPL (UK), PTB (Germany), IEN (Italy)

and the President of CCAUV

Document CCAUV 02 - 33

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AUV and Nanotechnology

Need to develop ever smaller transducers

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Achieving vibrational quantum limits with nanomembranes

New standards with acoustical or thermal phonons?

PHONON EMISSION ONE BY ONEPHONON EMISSION ONE BY ONE

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Schematic diagram of micromachined stereocilia mounted on a membrane, with piezoresistive strain sensors to measure deflection due to microflows (W. Tang).

Array of micromachined stereocilia.

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In the CCAUV section of the BIPM websitethere are documents of restricted access.

Most of them will be now be open for free access.

There is also an extense list of publications related to AUV.

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The unit one,

the neper and the bel

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Logic A (current logic)

– The ratio of two quantities of the same kind is a new quantity.

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Logic B• Division of one quantity by other of the same

kind merely express the number of times one quantity fits into the other.

• This number may be just called a coefficient, a factor or a ratio, but not a new quantity.

• No need to assign SI units to numbers!

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Logic A or Logic B?

It is a matter of choice

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PROBLEMS associated with Logic A

• CONFUSIONbetween levels, reference levels and the underlying quantities and SI units

• CONFUSION through special names

• CONFUSION through the use of the special name decibel with different power and field quantities such as dB(mW), dB(W), dB(0.775V), dB(V), dB(mA), dB(V/m), dB(W/m2), dB(W/4kHz), dB(W/K), dB(W/m2kHz), dB(kHz), dB(Pa), dB(Pa/V), dB(mV/Pa) and dB(K-1)

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The best recommendation should be to use more the accepted SI units underlying such ratios or levels as bel or neper