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Remote Visual Inspection or Remote Digital Video Inspection, also known as RVI or RDVI, is a form of visual inspection which uses visual aids including video technology to allow an inspector to look at objects and materials from a distance because the objects are inaccessible or are in dangerous environments. [1] RVI is also a specialty branch of nondestructive testing (NDT).
Technologies include, but not limited to, rigid or flexible borescopes, videoscopes, fiberscopes, push cameras, pan/tilt/zoom cameras and robotic crawlers. Remote are commonly used where distance, angle of view and limited lighting may impair direct visual examination or where access is limited by time, financial constraints or atmospheric hazards.
RVI/RDVI is commonly used as a predictive maintenance or regularly scheduled maintenance tool to assess the "health" and operability of fixed and portable assets. RVI/RDVI enables greater inspection coverage, inspection repeatability and data comparison.
The "remote" portion of RVI/RDVI refers to the characterization of the operator not entering the inspection area due to physical size constraints or potential safety issues related to the inspection environment.
Typical applications for RVI include:
Nondestructive testing (NDT) is any of a wide group of analysis techniques used in science and technology industry to evaluate the properties of a material, component or system without causing damage. The terms nondestructive examination (NDE), nondestructive inspection (NDI), and nondestructive evaluation (NDE) are also commonly used to describe this technology. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting, and research. The six most frequently used NDT methods are eddy-current, magnetic-particle, liquid penetrant, radiographic, ultrasonic, and visual testing. NDT is commonly used in forensic engineering, mechanical engineering, petroleum engineering, electrical engineering, civil engineering, systems engineering, aeronautical engineering, medicine, and art. Innovations in the field of nondestructive testing have had a profound impact on medical imaging, including on echocardiography, medical ultrasonography, and digital radiography.
A remotely operated underwater vehicle (ROUV) or remotely operated vehicle (ROV) is a free-swimming submersible craft used to perform underwater observation, inspection and physical tasks such as valve operations, hydraulic functions and other general tasks within the subsea oil and gas industry, military, scientific and other applications. ROVs can also carry tooling packages for undertaking specific tasks such as pull-in and connection of flexible flowlines and umbilicals, and component replacement. They are often used to visit wrecks at great depths beyond the capacities of submersibles for research purposes, such as the Titanic, amongst others.
Telerobotics is the area of robotics concerned with the control of semi-autonomous robots from a distance, chiefly using television, wireless networks or tethered connections. It is a combination of two major subfields, which are teleoperation and telepresence.
Infrared thermography (IRT), thermal video or thermal imaging, is a process where a thermal camera captures and creates an image of an object by using infrared radiation emitted from the object in a process, which are examples of infrared imaging science. Thermographic cameras usually detect radiation in the long-infrared range of the electromagnetic spectrum and produce images of that radiation, called thermograms. Since infrared radiation is emitted by all objects with a temperature above absolute zero according to the black body radiation law, thermography makes it possible to see one's environment with or without visible illumination. The amount of radiation emitted by an object increases with temperature; therefore, thermography allows one to see variations in temperature. When viewed through a thermal imaging camera, warm objects stand out well against cooler backgrounds; humans and other warm-blooded animals become easily visible against the environment, day or night. As a result, thermography is particularly useful to the military and other users of surveillance cameras.
A borescope is an optical instrument designed to assist visual inspection of narrow, difficult-to-reach cavities, consisting of a rigid or flexible tube with an eyepiece or display on one end, an objective lens or camera on the other, linked together by an optical or electrical system in between. The optical system in some instances is accompanied by illumination to enhance brightness and contrast. An internal image of the illuminated object is formed by the objective lens and magnified by the eyepiece which presents it to the viewer's eye.
Magnetic particle inspection (MPI) is a nondestructive testing process where a magnetic field is used for detecting surface, and shallow subsurface, discontinuities in ferromagnetic materials. Examples of ferromagnetic materials include iron, nickel, cobalt, and some of their alloys. The process puts a magnetic field into the part. The piece can be magnetized by direct or indirect magnetization. Direct magnetization occurs when the electric current is passed through the test object and a magnetic field is formed in the material. Indirect magnetization occurs when no electric current is passed through the test object, but a magnetic field is applied from an outside source. The magnetic lines of force are perpendicular to the direction of the electric current, which may be either alternating current (AC) or some form of direct current (DC).
Plastic welding is welding for semi-finished plastic materials, and is described in ISO 472 as a process of uniting softened surfaces of materials, generally with the aid of heat. Welding of thermoplastics is accomplished in three sequential stages, namely surface preparation, application of heat and pressure, and cooling. Numerous welding methods have been developed for the joining of semi-finished plastic materials. Based on the mechanism of heat generation at the welding interface, welding methods for thermoplastics can be classified as external and internal heating methods, as shown in Fig 1.
Eddy-current testing is one of many electromagnetic testing methods used in nondestructive testing (NDT) making use of electromagnetic induction to detect and characterize surface and sub-surface flaws in conductive materials.
Predictive maintenance techniques are designed to help determine the condition of in-service equipment in order to estimate when maintenance should be performed. This approach claims more cost savings over routine or time-based preventive maintenance, because tasks are performed only when warranted. Thus, it is regarded as condition-based maintenance carried out as suggested by estimations of the degradation state of an item.
Phased array ultrasonics (PA) is an advanced method of ultrasonic testing that has applications in medical imaging and industrial nondestructive testing. Common applications are to noninvasively examine the heart or to find flaws in manufactured materials such as welds. Single-element probes, known technically as monolithic probes, emit a beam in a fixed direction. To test or interrogate a large volume of material, a conventional probe must be physically scanned to sweep the beam through the area of interest. In contrast, the beam from a phased array probe can be focused and swept electronically without moving the probe. The beam is controllable because a phased array probe is made up of multiple small elements, each of which can be pulsed individually at a computer-calculated timing. The term phased refers to the timing, and the term array refers to the multiple elements. Phased array ultrasonic testing is based on principles of wave physics, which also have applications in fields such as optics and electromagnetic antennae.
Electromagnetic testing (ET), as a form of nondestructive testing, is the process of inducing electric currents or magnetic fields or both inside a test object and observing the electromagnetic response. If the test is set up properly, a defect inside the test object creates a measurable response.
An electromagnetic acoustic transducer (EMAT) is a transducer for non-contact acoustic wave generation and reception in conducting materials. Its effect is based on electromagnetic mechanisms, which do not need direct coupling with the surface of the material. Due to this couplant-free feature, EMATs are particularly useful in harsh, i.e., hot, cold, clean, or dry environments. EMATs are suitable to generate all kinds of waves in metallic and/or magnetostrictive materials. Depending on the design and orientation of coils and magnets, shear horizontal (SH) bulk wave mode, surface wave, plate waves such as SH and Lamb waves, and all sorts of other bulk and guided-wave modes can be excited. After decades of research and development, EMAT has found its applications in many industries such as primary metal manufacturing and processing, automotive, railroad, pipeline, boiler and pressure vessel industries, in which they are typically used for nondestructive testing (NDT) of metallic structures.
Infrared vision is the capability of biological or artificial systems to detect infrared radiation. The terms thermal vision and thermal imaging are also commonly used in this context since infrared emissions from a body are directly related to their temperature: hotter objects emit more energy in the infrared spectrum than colder ones.
Terahertz nondestructive evaluation pertains to devices, and techniques of analysis occurring in the terahertz domain of electromagnetic radiation. These devices and techniques evaluate the properties of a material, component or system without causing damage.
Active thermography is an advanced nondestructive testing procedure, which uses a thermography measurement of a tested material thermal response after its external excitation. This principle can be used also for non-contact infrared non-destructive testing (IRNDT) of materials.
Robotic non-destructive testing (NDT) is a method of inspection used to assess the structural integrity of petroleum, natural gas, and water installations. Crawler-based robotic tools are commonly used for in-line inspection (ILI) applications in pipelines that cannot be inspected using traditional intelligent pigging tools.
Air-Cobot (Aircraft Inspection enhanced by smaRt & Collaborative rOBOT) is a French research and development project of a wheeled collaborative mobile robot able to inspect aircraft during maintenance operations. This multi-partner project involves research laboratories and industry. Research around this prototype was developed in three domains: autonomous navigation, human-robot collaboration and nondestructive testing.
Underwater work is work done underwater, generally by divers during diving operations, but includes work done underwater by remotely operated vehicles and crewed submersibles.
An underwater survey is a survey performed in an underwater environment or conducted remotely on an underwater object or region. Survey can have several meanings. The word originates in Medieval Latin with meanings of looking over and detailed study of a subject. One meaning is the accurate measurement of a geographical region, usually with the intention of plotting the positions of features as a scale map of the region. This meaning is often used in scientific contexts, and also in civil engineering and mineral extraction. Another meaning, often used in a civil, structural, or marine engineering context, is the inspection of a structure or vessel to compare actual condition with the specified nominal condition, usually with the purpose of reporting on the actual condition and compliance with, or deviations from, the nominal condition, for quality control, damage assessment, valuation, insurance, maintenance, and similar purposes. In other contexts it can mean inspection of a region to establish presence and distribution of specified content, such as living organisms, either to establish a baseline, or to compare with a baseline.
Underwater exploration is the exploration of any underwater environment, either by direct observation by the explorer, or by remote observation and measurement under the direction of the investigators. Systematic, targeted exploration is the most effective method to increase understanding of the ocean and other underwater regions, so they can be effectively managed, conserved, regulated, and their resources discovered, accessed, and used. Less than 10% of the ocean has been mapped in any detail, less has been visually observed, and the total diversity of life and distribution of populations is similarly obscure.