No surface in the world is completely smooth. Every surface has at least a bare minimum roughness. Roughness plays an important role in determining how an object interacts with its environment. Rough surfaces wear quickly and have a higher frictional coefficient. Roughness is useful for gripping (by hand) purpose as well as for adhesion. Indeed, a completely smooth surface will not promote adhesion, meaning that coatings cannot be applied. Similarly, a smooth surface is difficult to grip. A controlled surface roughness is usually preferred.

Surface roughness measurement involves manual comparison of the roughness of a given surface with that of a standard surface. The comparators can be of a contact type with a diamond stylus or optical type. Values available include average of deviations from mean line (Ra) and maximum peak to valley height (Rz).

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.

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.

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.

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.

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.

In-situ metallography is used to determine degradation of components under weather, temperature, pressure and corrosive atmospheres. This technique enables real-time component condition monitoring and health assessments.

In-situ Metallography and replication is used for microstructural analysis while examining large components that cannot be easily moved or when destructive sample preparation is difficult or not permissible. The testing allows quick on-site evaluation of a component’s metallurgical and heat treatment condition and assists investigators in carrying out a remaining life assessment study or a failure analysis project.

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.

In-situ metallography is used to determine degradation of components under weather, temperature, pressure and corrosive atmospheres. This technique enables real-time component condition monitoring and health assessments.

Grain sizes can be measured by means of Ultrasonic Testing. Sound waves are reflected off the various grain boundaries. Depending upon the number and size of grains, the reflections and diffractions of the sound waves can be measured, thereby giving an indication of the number and size of grains present in the material. Grain size is then calculated as per various standards.

Metals have a natural tendency to go back to the least-energy state. For most metals, this happens to be in the form of the ore in which they are usually extracted. As a result, the metals tend to form into oxides, which are the most stable state with the least energy. Commonly known as rust or patination, the thickness of the oxide layer determines various properties, including propagation or restriction of further corrosion and loss in thickness.

Oxide layer thickness measurement utilises ultrasonic waves to determine the thickness. Ultrasonic signals are traversed through the layer, whereby they come in contact with the base metal eventually. Upon contact, they are reflected back, which are then received and analysed. Determination of this thickness enables calculation of the depth till which the artefact needs to be cleaned so as to remove the scale, but not damage the original metal underneath.

Different locations around the world have different types of soils. The properties of each type of soil is dependent upon its constituent elements. These elements give the soil its unique properties, which further determine the use for that particular type of soil. For e.g. soil properties for agriculture, brick firing and other such operations would vary from each other.

Any item lying in the ground for many years ends up picking some materials, and by extension properties, of the soil. This is especially true in the case of stone tools and lithics found in different types of soil. A layer of patination would form on an otherwise unpatinated sample. This layer would determine the properties, and in itself would be dependent upon the type of soil that the item is found in.

Each colour found in the world, whether natural or artificial, has its own signature parameter. Various scales can be used, such as R,G,B; L*,a*,b* and so on. Under each different scale, every unique colour has its own dedicated parameter value. For example, under the RGB scale, Green has a parameter of 0,255,0 or white has a parameter of 255,255,255.

Determination of the actual colour can be useful in determining the original colour that was used. It can also be used to determine whether a new colour being applied matches with the original one. This is especially useful while conducting conservation of paintings, frescos and other items where originality of colour is essential.

Quite often, large areas need to be surveyed in short periods of time. These could include for studies of the land, structure, rock formations etc. Likewise, inspections of various items located at heights may be required. In such cases, physically climbing to the said height may be tiresome and dangerous.

Aerial inspection by drones, or Unmanned Aerial Vehicles (UAV) can be effectively used for quick scanning of large, inaccessible or dangerous areas, saving time and effort. The scans can be seen live on various screens. The data can be saved, transferred and analysed as required.