Non-Destructive Evaluation in the Preservation Toolbox

by Mary F. StriegelNational Center for

Preservation Technology and Training

Cultural heritage is deteriorating from natural and manmade causes.

NCPTT was created to develop or transfer new technologies to the world of historic preservation.

Without nondestructive testing of Cultural Heritage, appropriate treatments cannot be made.

New advances in NDT hold the promise of new ways to study and conserve our cultural heritage.

What is Cultural Heritage?

KellyMullaney, “Cultural Exhibits during Hispanic Heritage Family Day,” October 21, 2008, online image, flickr.

Architectural buildings and structures. . .

Archeological sites and collections. . .

Art or historical collections. . .

Parks, gardens and other landscapes can all be considered cultural heritage.

Cultural resources are subjected to many agents of deterioration.

Natural decay goes unchecked from lack of understanding of chemical/physical properties.

Well-meaning but inappropriate maintenance leads to loss of materials.

Natural disasters have devastating effects on cultural resources.

Manmade destruction results from lack of understanding or appreciation of resources.

Nondestructive testing methods can help to understand the physical aspects of cultural heritage.

Eddy Current Testing

Eddy current testing provides a way to study gilded surfaces

Infrared Thermography

Infrared Thermography is used to monitor the consolidation of voids and delamination on stone artifacts in real time.

Evaluation of Infrared Thermography for Monitoring the Consolidation of Voids and Delamination on Stone Artifacts in Real Time, 2002 PTT Grant, Nelson Atkins Museum

Infrared Thermography is used to identify presence of termites in St. Alphonsus Church, New Orleans.

Laser speckle interferometry

The Getty Conservation InstituteHerculaneum Projecthttp://www.getty.edu/conservation/science/herculaneum/index.htmlAccessed 3/12/2009

Laser Speckle Interferometry detects stucco detachment in wall paintings.

The Getty Conservation InstituteHerculaneum Projecthttp://www.getty.edu/conservation/science/herculaneum/index.htmlAccessed 3/12/2009

The method follows the injection of grout as a corrective treatment.

Nondestructive testing methods provide a way to look at the chemical nature of cultural heritage.

NMR (nuclear magnetic resonance) MOUSE

NMR MOUSE can help follow

deterioration of pigments in paintings.

Portable XRF

Copper Artifacts from the Gahagan Site,Northwestern State University of LA

pXRF is used to determine provenance of metal objects.

The technique can be used to study chemical changes after treatments.

A new portable XRD/XRF instrument has been built for the study of works of art.

PORTABLE XRD/XRF INSTRUMENTATION FOR THE STUDY OF WORKS OF ART

G. Chiari, P. Sarrazin, M. Gailhanou

This technique allows for both elemental and mineral phase identification.

Nondestructive evaluation can help us image cultural heritage in new ways.

Reflectance & Transmittance Imagingat the Library of CongressFenella France & Michael Toth

Acoustic Microscopy

Scanning acoustic microscopy (SAM) relies on the propagation of sound waves to create images of materials.

Non-Destructive Imaging of Worn-Off Hallmarks and Engraving from Metal Objects of Art Using Scanning Acoustic Microscopy, 2000 PTT Grant, Nelson Atkins Museum

SAM is used to identify worn hallmarks on silver objects.

Non-Destructive Imaging of Worn-Off Hallmarks and Engraving from Metal Objects of Art Using Scanning Acoustic Microscopy, 2000 PTT Grant, Nelson Atkins Museum

3D Laser Imaging

High Definition Documentation of Archeology, 2006 PTT Grant, CyArk

3D laser imaging has been used to document the Statue of Liberty.

Reflectance Transformation Imaging

CHI Imaging, chersonsos_018_P7213802,” February 19, 2009, online image, Flickr.www.c-h-i.org

RTI is used to study Rock Art sites.

CHI Imaging, “_MG_0360,” December 17, 2008, online image, Flickr,www.c-h-i.org

CHI Imaging, “full_goat_digital_image,” December 17, 2008, online image, Flickr, www.c-h-i.org

Cultural Heritage Imaging of Coa Rock Art Site

It has also been used to evaluate mosaics in Herculaneum.

The Getty Conservation InstituteHerculaneum Projecthttp://www.getty.edu/conservation/science/herculaneum/index.htmlAccessed 3/12/2009

The nondestructive evaluation industry must be engaged in preservation to find new ways to save our cultural heritage.

Without a technical framework for treatment decision making, conservators and preservationists are left to trial and error.

Nondestructive testing offers new tools to save cultural heritage.