ITEMS ACCURATE MARKING
◉ Visual testing is unique in that it is. Answer: The only method that
reveals indication of discontinuities directly.
◉ One of the first aids used in visual testing was developed for
another industry and was called a(n):. Answer: Endoscope
◉ One of the advantages of visual testing is that it can be used:.
Answer: any time during the manufacture or life of the product
◉ Often visual testing is performed in two steps:. Answer: an initial
inspection at lower light levels and without magnification, and a
second inspection evaluating anomalies located using higher light
levels and magnification.
◉ Contrast may be increased by:. Answer: Increasing differences in
reflectivity, color difference, or discoloration,
◉ Surface discontinuities that are located with visual testing
include:. Answer: Cracks and voids in all materials.
,◉ A limitation of visual testing is the:. Answer: Need for
discontinuities to be surface level.
◉ Visual testing differs from other NDT methods in that:. Answer:
the discontinuities are visible to the eye.
◉ Visual testing might be called the __________ of all NDT.. Answer:
Foundation
◉ The difference between different forms of electromagnetic
radiation is their:. Answer: Wavelength
◉ Visible light is defined as electromagnetic radiation observed by
the human eye and is in the range of:. Answer: 400 to 700
nanometers
◉ The "candela" is an SI unit that measures:. Answer: The intensity
of a light source.
◉ As light moves from the source, intensity is reduced. This is
because:. Answer: Light becomes more diffused as it moves away
from the source.
, ◉ As light strikes a rough or faceted surface, it is:. Answer: reflected
in a number of directions.
◉ Light incident on a material:. Answer: may be absorbed, reflected,
or transmitted depending on the material.
◉ A luminance difference from a crack in a sound area will produce
what is known as:. Answer: Contrast
◉ When viewing materials, the reflection from small discontinuities
can be located more easily and with less eye fatigue:. Answer: If the
light intensity is reduced.
◉ Field inspections often require the inspector to:. Answer: wear
personal safety equipment, use additional lighting, and be aware of
hazards in the inspection are.
◉ The eyes contain photoactive cells, which send signals to the brain
that are then formed into an image. Familiar images are quickly
identified by the brain; however, new images of discontinuities
arriving in the brain:. Answer: may often be overlooked and leave
the discontinuities to remain undetected as they are unknown
images.