International Workshop — SMW 08 IN SITU MONITORING

International Workshop - SMW 08 IN SITU MONITORING OF MONUMENTAL SURFACES Florence, 27 -29 October 2008 28 th 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 paola. calicchia@idac. rm. cnr. it SMW 08 28 th October Page 1 P. Calicchia

ACEADD: portable device for NDT of fresco detachments based on the ACOUSTIC ENERGY ABSORPTION evaluation üBACK REFLECTION SETTING üsource S and receiver M in COAXIAL CONFIGURATION and NORMAL INCIDENCE GEOMETRY üworking distance from the surface is about 0, 5 m ümeasure of the abs. coeff. by the determination of the transfer function a(w) = 1 - |HS(w)|2 üDIRECT EXTRAPOLATION of the surface impulse response h. S(t) by means of Cepstrum algorithm signal processing üwide band SINE WAVE SWEEP 100 Hz ÷ 15 k. Hz üit provides 2 D and 3 D ACOUSTIC ABSORPTION MAPS and ROUGHNESS MAPS for the LOCALIZATION and CHARACTERIZATION of detachments. (G. B. Cannelli, P. Calicchia, US Patent US 6728661 27, European Patent EP 1190243 B 1") (2) (1) (3) (4) ACEADD – ACOUSTIC ENERGY ABSORPTION DIAGNOSTIC DEVICE 28 th October Page 2 SMW 08 P. Calicchia

MEASURING THE ACOUSTIC ENERGY ABSORPTION COEFFICIENT a(w) DETERMINATION OF ACOUSTIC PROPERTIES AND PERFORMANCE OF MATERIALS CHARACTERIZATION AND CERTIFICATION OF MATERIALS, STRUCTURES AND SURFACES EMPLOYMENT OF BOTH LABORATORY AND IN SITU METHODOLOGIES ROAD PAVEMENTS & NOISE BARRIERS ABSORBENT PANELS & STRUCTURES ABSORBENT MATERIALS (polyurethane foam, wool, wood, many porous or fibrous materials) 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” THE ACOUSTIC ABSORPTION COEFFICIENT 28 th October Page 3 SMW 08 P. Calicchia

REFLECTION COEFFICIENT AT NORMAL INCIDENCE R= Z 2 – Z 1 Z 2 + Z 1 2 Z 2 >> Z 1 R=1 Z=rc A DETACHMENT IS LIKE A VIBRATING DISK OR MEMBRANE WITH AN ENCLOSED VOLUME OF AIR BEHIND ARRICCIO INTONACHINO SUPPORT AND BEHAVES LIKE AN ACOUSTIC ABSORBER ACEADD – ACOUSTIC ENERGY ABSORPTION DIAGNOSTIC DEVICE 28 th October Page 4 SMW 08 P. Calicchia

Copyright © Andrew Marsh, UWA, 1999. The School of Architecture and Fine Arts The University of Western Australia Porous Absorbers Membrane Absorbers Perforated Panel Absorbers Cavity Absorbers SOUND ABSORPTION IN MATERIALS AND STRUCTURES 28 th October Page 5 SMW 08 P. Calicchia

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 ACEADD – THE MEASURING PROCEDURE 28 th October Page 6 5 - THE CONTROL OF THE SCAN UNIT SMW 08 P. Calicchia

6 – THE MOTION CONTROL AND THE ACQUISITION (… is it time consuming? LAB INSTR. : 120 pts in 1 h, 600 pts in 5 h covering 96 cm x 76 cm with 4 cm 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, Tamb, RH% 8 - THE MAX REFLECTION REFERENCE POINT (or standard reference material calibration) ACEADD – THE MEASURING PROCEDURE 28 th October Page 7 SMW 08 P. Calicchia

Vasari House, Florence 60% 40% 9 - DATA ANALYSES (different analyses available) The ACEADD provides the restaurateur artists with objective data, supporting the following actions: ü DIAGNOSIS of the degree of deterioration of mural paintings; ü EVALUATION OF CONSOLIDATION WORKS based on purposely defined criteria; üMONITORING of detachments by means of periodic exams. ACEADD – THE MEASURING PROCEDURE 28 th October Page 8 SMW 08 P. Calicchia

CONSERVATION ENTERPRISE & ORGANIZATION Scientific Research CULTURAL HERITAGE MANAGEMENT ORGANIZATION -Industrial Research - Engineering (prototypes) ENGINEERING & DISTRIBUTION DIAGNOSTICS SERVICES ENTERPRISE RESEARCH ORGANIZATIONS TT ACTIONS Page 9 INSTITUTES & EDUCATION ORGANIZATION ACEADD INDUSTRIAL PROTOTYPE ACEADD – RESEARCH & DEVELOPMENT PLAN 28 th October Transfer to Market SMW 08 P. Calicchia

METHODOLOGICAL AND TECHNOLOGICAL ADVANCEMENTS NON LINEAR ACOUSTIC SOURCE DIRECTIVE SOUND SOURCE STANDARDIZATION OF THE METHODOLOGY AND DEVICE CALIBRATION ADVANCED SOLUTIONS FOR ENERGY GENERATION AND ENERGY HARVESTING ADVANCED SOLUTIONS FOR DATA STORAGE AND DATA TRANSFER ADVANCED SOLUTIONS (WIRELESS TECHNOLOGIES) FOR MINIMUM SIZE DEVICE MODELLING OF REAL DETACHMENTS RESPONSE OF CONSOLIDANTS INNOVATIVE SOLUTIONS FOR ALTERNATIVE CONFIGURATION (xi, yi) 80% 60% 30% (xi, yi, hi, ti, Hi(w), di, … , imgi, Tamb, RH%) ACEADD – RESEARCH & DEVELOPMENT PLAN 28 th October Page 10 SMW 08 P. Calicchia