Heritage Conservation
Art & Culture
Art and culture plays an important role in society. It enables understanding of the history of the society, which in-turn enables learnings about the life and its richness. Art and culture includes various items including, but not limited to:
- Statues
- Idols
- Structures
- Temples
- Churches
- Papyruses
- Manuscripts
- Paintings
- Artefacts
- Murals
Different methods of NDE can be effectively used in the fields of Art and Culture for various applications. The information obtained through the results of NDE can be used to formulate plans for conservation and preservation of such artefacts.
Anthropological Sciences
Anthropological sciences include fields of science related to humans and other living organisms. Non- Destructive Examination can be effectively used in the fields of Anthropology and its related disciplines.
The various fields and disciplines of anthropological sciences where NDE can be effectively used are:
- Anthropology
- Geology
- Archaeology
- Archaeozoology
- Geomorphology
- Palaeontology
- Palynogy
- Palaeobotany
- Numismatics
The list above is not exhaustive and additional sciences and disciplines may also be possible.
Different existing NDE methods can be effectively used for inspection and examination in the various disciplines. These include:
Computerized / Digital Radiography (CR/DR)
Computerized (CR) and Digital (DR) are modern types of Radiographic Testing. CR makes the use of a Phosphor Imaging Plate to obtain a digital image. CR uses a cassette based system like conventional film radiography, and can be considered to be a bridge between conventional film radiography and digital radiography. Certain advantages include low initial investment and the availability of various sizes enabling flexibility.
DR uses a Digital X-ray detector to automatically acquire images and transfer them to a computer for viewing. It is capable of fixed or mobile use. Certain advantages include faster image capture, better quality images and high volume capacity.
Both CR and DR can be used for determination of internal structures of various artefacts.
Typical Applications
Determination of internal structure and analysis of construction method of idols, statues, paintings, artefacts and other items.
Computerized Tomography (CT)
Computerized Tomography is similar to Computerized Radiography. More popularly known as CT Scan, Tomography is utilized to obtain 2D and 3D images of small and minute objects such as pollen grains, flowers, leaves, textile threads and so on. The ability of x-ray to penetrate through varying densities allows CT inspection results to provide non-destructive physical characterization of internal features and structures of a part or component.
Typical Applications
Determination of internal structure and analysis of construction method of idols, statues, paintings, artefacts and other items.
Infrared Thermography (IR):
Infrared Thermography involves determination of heat signatures of various objects, especially those that are exposed to weather conditions. IR uses a temperature gun to indicate surface temperatures. A range of temperatures over the surface can be detected. Heat areas are segregated by means of a colour palette where areas of different temperatures are indicated by different colours.
Typical Applications
Determination of heat signatures and internal flaws in artefacts, paintings, statues, idols and other items.
Remote Visual Inspection (RVI)
Remote Visual Inspection involves inspection of inaccessible and dangerous areas remotely. It involves the use of borescopes, videoscopes and Wireless Fidelity. RVI makes the inspection of inaccessible areas possible, especially where access is restricted due to space constraints.
Typical Applications
Inspection of inaccessible areas such as tunnels, gorges, burrows, small openings and holes. It also involves inspection of areas that are inaccessible due to inherent dangers or space restrictions.
Coating Thickness Measurement
Various coatings can be applied on to objects to protect them from the effects of the environment. The thickness of the various coatings reduces over time. The thickness determines the life of the coating, which in-turn determines the protection it would afford the item in question. Coating thicknesses can be measured using the eddy current or the ultrasonic testing methods as per the case.
Typical Applications
Measurement of thickness of various coatings on different substrates.
Thickness Gauging
Corrosion and wear of items causes their thicknesses to reduce. Reduction of thicknesses to below a certain value would make the item too thin and eventually fail. Thickness gauging is involves measuring the actual thickness of metallic items to determine their current condition and remaining life.
Typical Applications
Measurement of actual thickness of metallic items to determine their current condition and remaining life.
X-Ray Fluorescence Spectrometry (XRF)
X-Ray Fluorescence Spectroscopy (XRF) is Positive Material Identification (PMI) Technique. PMI is useful in determining the constituents of any item, without causing any damage or loss of utility of the item.
Based on the principle that individual atoms, when excited by an external energy source, emit X-ray photons of different characteristic wavelengths. Analysis of the intensity and actual wavelengths of these photons provides information regarding the composition and individual concentration of various elements in the item tested.
Typical Applications
Determination of constitution of materials in soils, fossils, rocks, stones, idols, statues and other items.
Infrared Thermography (IR):
Infrared Thermography involves determination of heat signatures of various objects, especially those that are exposed to weather conditions. IR uses a temperature gun to indicate surface temperatures. A range of temperatures over the surface can be detected. Heat areas are segregated by means of a colour palette where areas of different temperatures are indicated by different colours.
Typical Applications
To determine temperatures and heat signatures of various items.
Surface Hardness Testing
Hardness Testing involves measurement of surface hardness of a component. Surface hardness is the resistance to surface penetration. Hardness of a component depends upon the material composition, process it has undergone and heat cycles it has been subjected to. There are very few material limitations for hardness testing.
Hardness Testing can be carried out to measure any of the six hardness values – Brinell, Rockwell, Vickers, Knoop, Mohs and Shore. In case any value is not detected by the equipment, the values can be converted to any other value using set formulae. Hardness testing is of two basic types – Ultrasonic, where use is made of ultrasonic (sound) signals to determine the surface hardness, which leaves no mark on the sample being tested, and Rebound, where use is made of a small steel ball to impact against the surface being tested, which may leave a small (micron diameter and depth) indentation on the sample being tested.
Typical Applications
Surface hardness measurement of stone, rock, metal, bone, fossils and all similar samples.
Corrosion Mapping
Corrosion of metals is a serious problems that causes loss of material and permanent damage to an item. Corrosion mapping is used to determine the loss in metal in percentage values. It provides a reading based on how much percentage of the original thickness/ dimension is remaining, in the form of a coloured image graph.
Typical Applications
Determination of loss of thickness in percentage values for ferromagnetic materials. Used to determine how much longer the item could last based on its current condition.