ASNT Level 3 Visual Testing Course
ASNT Level 3 Visual Testing Course Fees 450 $ | ASNT Level 3 Visual Testing Course Exam Fees To be informed | ASNT Level 3 Visual Testing Course Duration 20 Days | ASNT Level 3 Visual Testing Course Location Muscat
Visual Testing
Visual testing is the subject of the present volume and of a volume in the previous edition.
Principles.
Visual testing is the observation of a test object, either directly with the eyes or indirectly using optical
instruments, by an inspector to evaluate the presence of surface anomalies and the object’s conformance to specification.
Visual testing should be the first nondestructive test method applied to an item. The test procedure is to clear obstructions from the surface, provide adequate illumination and observe. A prerequisite necessary for competent visual testing of an object is knowledge of the manufacturing processes by which it
was made, of its service history and of its potential failure modes, as well as related industry experience.
Applications.
Visual testing is widely used on a variety of objects to detect surface discontinuities associated with various structural failure mechanisms. Even when other nondestructive tests are performed, visual tests often provide a useful supplement. When the eddy current testing of process tubing is performed, for
example, visual testing is often performed to verify and more closely examine the surface condition.
ASNT Level 3 Visual Testing Course covers the following discontinuities may be detected by a simple visual test: surface discontinuities, cracks, misalignment, warping, corrosion, wear and physical damage.
Selection of Visual Testing
Visual testing is an important method in the broad field of nondestructive testing. Visual testing is used to locate surface anomalies in most materials and subsurface discontinuities in translucent materials. Visual testing is performed either by a direct technique or by a remote (that is, indirect) technique. One
definition of the direct technique is to place the eye within 600 mm (24 in.) and not less than 30 degrees from the test surface.
Mirrors may be used to improve the angle of vision, and aids such as magnifying lenses may be used to assist examinations. ASNT Level 3 Visual Testing Course covers the remote, or indirect, technique may include accessories such as mirrors, borescopes, video probes or cameras to correct for the distance or angles of view. With a remote (indirect) technique, resolution must be equivalent to that of the direct technique.
Visual test equipment is designed to detect structural characteristics of a part. These characteristics range from simple surface discontinuities on flat surfaces to various fabrication or inservice discontinuities in complex geometries.
As a result, specific applications have been developed using visual testing: detecting discontinuities in fabricated structures such as airframes, piping and pressure vessels, ships, bridges, motor vehicles and machinery and predicting the impending failure in highly stressed components exposed to the various
modes of fatigue.
Advantages
The visual method is a sensitive means of locating surface anomalies in various materials. There is little or no limitation on the size or shape of the part being inspected. Indications provide a graphic representation of the actual discontinuity.
Precleaning may be necessary if the surface cleanliness impairs an adequate view of the test surface, but discontinuities filled with foreign material may be detected. The need for precleaning will largely depend on the size and type of discontinuities specified by acceptance criteria.
The following are the primary advantages typically associated with visual testing: (1) economy, (2) speed, (3) sensitivity, (4) versatility, (5) applicability to irregular shapes, (6) field mobility, (7) minimal training requirements and (8) minimal equipment requirements.
Limitations
Visual testing requires a line of sight to the test surface and lighting adequate to detect and interpret anomalies of interest. Visual testing may be limited by component geometry: size, contour, surface roughness, complexity and discontinuity orientation.
Remote visual equipment may be required to access interior surfaces and remote equipment providing adequate viewing angles, sensitivity, resolution and illumination may be costly. For proper interpretation of indications, the inspector needs skill with the technique used, experience using the visual equipment
and knowledge of the test object.
Contact Us
ASNT Link