1. International Workshop - SMW08
IN SITU MONITORING OF MONUMENTAL SURFACES
Florence, October 2008
28th October
Session 3
Geo-physical and mechanical properties
SURFACE CHARACTERIZATION OF FRESCOES
BY MEANS OF ACOUSTIC IMAGE DIAGNOSTICS
AND DIGITAL IMAGE PROCESSING
P. Calicchia, G. B. Cannelli, M. Poscolieri
CNR Institute of Acoustics “O. M. Corbino”, Rome
Paola Calicchia
28th October

2. ACEADD: portable device for NDT of fresco detachments based on the ACOUSTIC ENERGY ABSORPTION evaluation
BACK REFLECTION SETTING
source S and receiver M in COAXIAL CONFIGURATION and NORMAL INCIDENCE GEOMETRY
working distance from the surface is about 0,5m
measure of the abs. coeff. by the determination of the transfer function a(w) = 1 - |HS(w)|2
DIRECT EXTRAPOLATION of the surface impulse response hS(t) by means of Cepstrum algorithm signal processing
wide band SINE WAVE SWEEP 100Hz ÷ 15kHz
it provides 2D and 3D ACOUSTIC ABSORPTION MAPS and ROUGHNESS MAPS for the LOCALIZATION and CHARACTERIZATION of detachments.
(G. B. Cannelli, P. Calicchia, US Patent US , European Patent EP B1")
(1)
(2)
(3)
(4)
ACEADD – ACOUSTIC ENERGY ABSORPTION DIAGNOSTIC DEVICE
28th October

3. a(w) MEASURING THE ACOUSTIC ENERGY ABSORPTION COEFFICIENT
DETERMINATION OF ACOUSTIC PROPERTIES AND PERFORMANCE OF MATERIALS
CHARACTERIZATION AND CERTIFICATION OF MATERIALS, STRUCTURES AND SURFACES
EMPLOYMENT OF BOTH LABORATORY AND IN SITU METHODOLOGIES
INTERNATIONAL STANDARD METHODS
ISO 354:2003 “MEASUREMENT OF SOUND ABSORPTION IN A REVERBERATION ROOM”
ISO 13472:2002, “MEASUREMENT OF SOUND ABSORPTION PROPERTIES OF ROAD SURFACES IN SITU”
ROAD PAVEMENTS & NOISE BARRIERS
ABSORBENT MATERIALS
(polyurethane foam, wool, wood, many porous or fibrous materials)
ABSORBENT PANELS & STRUCTURES
ISO 13472: Part 1: Exended surface method
Part 2: Spot method for reflective surfaces, draft version
Part 3: Spot method for absorptive surfaces, draft version
THE ACOUSTIC ABSORPTION COEFFICIENT
28th October

4. Reflection coefficient at Normal incidence
Z2 – Z1
Z2 + Z1 2
Reflection coefficient
at Normal incidence
Z2 >> Z1
Z = r c
R = 1
ARRICCIO
SUPPORT
INTONACHINO
A detachment is like a vibrating disk or membrane with an enclosed volume of air behind
And behaves like an acoustic absorber
ACEADD – ACOUSTIC ENERGY ABSORPTION DIAGNOSTIC DEVICE
28th October

5. Perforated Panel Absorbers
Copyright © Andrew Marsh, UWA, 1999.
The School of Architecture and Fine Arts
The University of Western Australia
Porous Absorbers
Membrane Absorbers
Cavity Absorbers
Perforated Panel Absorbers
SOUND ABSORPTION IN MATERIALS AND STRUCTURES
28th October

6. ACEADD – THE MEASURING PROCEDURE
1 - THE PICTURE OF THE FRESCO
2 - THE DEFINITION OF THE ANALYSED AREA
3 - THE CHOISE OF THE SOME REFERENCE POINTS
4 - THE CHOISE OF THE WORKING DISTANCE
5 - THE CONTROL OF THE SCAN UNIT
ACEADD – THE MEASURING PROCEDURE
28th October
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7. ACEADD – THE MEASURING PROCEDURE
6 – THE MOTION CONTROL AND THE ACQUISITION
(… is it time consuming?
LAB INSTR.: 120 pts in 1h,
600 pts in 5h covering 96cm x 76cm with 4cm step)
7 - THE SIGNAL PROCESSING
CEPSTRUM ALGORITHM
(resolves the reflection peak from the direct signal even when they are superposed in the time history)
xi, yi, hi, ti, Hi(w), di, … , imgi, Ti, Tamb, RH%
8 - THE MAX REFLECTION REFERENCE POINT
(or standard reference material calibration)
ACEADD – THE MEASURING PROCEDURE
28th October
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8. ACEADD – THE MEASURING PROCEDURE
40%
60%
Vasari House, Florence
9 - DATA ANALYSES
(different analyses available)
The ACEADD provides the restaurateur artists with objective data, supporting the following actions:
DIAGNOSIS of the degree of deterioration of mural paintings;
EVALUATION OF CONSOLIDATION WORKS based on purposely defined criteria;
MONITORING of detachments by means of periodic exams.
ACEADD – THE MEASURING PROCEDURE
28th October

9. ACEADD INDUSTRIAL PROTOTYPE
CONSERVATION
ENTERPRISE & ORGANIZATION
ENGINEERING & DISTRIBUTION
DIAGNOSTICS SERVICES ENTERPRISE
CULTURAL HERITAGE
MANAGEMENT ORGANIZATION
INSTITUTES
& EDUCATION ORGANIZATION
Scientific Research
Industrial Research
Engineering (prototypes)
Transfer to Market
RESEARCH ORGANIZATIONS
PROCESS OF TECHNOLOGICAL TRANSFER
TRYING TO ACCESS INDUSTRIAL RESEARCH
TRYING TO COOPERATE WITH END USER & ENGENEERING ENTERPRISE
ACEADD INDUSTRIAL PROTOTYPE
TT ACTIONS
ACEADD – RESEARCH & DEVELOPMENT PLAN
28th October
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10. METHODOLOGICAL AND TECHNOLOGICAL ADVANCEMENTS
ADVANCED SOLUTIONS
FOR MINIMUM SIZE DEVICE
ADVANCED SOLUTIONS FOR
DATA STORAGE AND DATA TRANSFER
(WIRELESS TECHNOLOGIES)
FOR ENERGY GENERATION
AND ENERGY HARVESTING
NON LINEAR ACOUSTIC SOURCE
DIRECTIVE SOUND SOURCE
STANDARDIZATION
OF THE METHODOLOGY
AND DEVICE CALIBRATION
MODELLING OF REAL DETACHMENTS
RESPONSE OF CONSOLIDANTS
80%
60%
30%
(xi, yi, hi, ti, Hi(w), di, … , imgi, Ti, Tamb, RH%)
(xi, yi)
INNOVATIVE SOLUTIONS FOR ALTERNATIVE CONFIGURATION
ACEADD – RESEARCH & DEVELOPMENT PLAN
28th October
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