Factors Affecting Radiographic Inspections Flashcards
What is determined by the thickness and composition of the material being inspected
Kilovoltage
Kilovoltage controls what
Quality and intensity of radiation
Energy level chosen must be compatible with what of the material
Absorption capability
Low absorbing objects
Have low KV, better contrast, less latitude
High absorbing objects
Have high KV, less contrast, better latitude
High kilovoltage means shorter or greater wavelength lesser or greater penetration and more or less absorption of energy
Shorter wavelength, greater penetration, less absorption of energy
Lowest practical KV
Better contrast, better sensitivity
Milliamperage controls what
Quantity and intensity of radiation
What is known as the distance between source and imaging plate
Source to IP distance (SIPD)
Source to IP distance is directly proportional to what
Exposure time (MAS)
What allows for compensation of distance when there is a deviation from the distance of the desired technique
Distance compensation due to object space, etc.
Define exposure geometry
Geometrical set up used to produce radiographic images.
Geometrical relationships affect what
Image sharpness and help control image distortion
Geometric factors control what
Distortion, alignment of defects, and clarity
What are the five geometric factors
- focal spot size (small as possible) (1.5mm)
- SIPD (As far as possible)
- beam to IP alignment (90° to IP)
- IP to object distance (close as possible to area of interest)
- object to film alignment (parallel to IP)
Image unsharpness is due to what
Size of source and relative distance
The distance over the age of the part is
Penumbral shadow of geometric unsharpness
Penumbral shadow can also be calculated using a what
Nomogram
A nomogram plots what
Distance (SIPD), focal spot, and thickness of geometrically unsharp object
For good definition/detail the Ug should be how big
.09 mm
Radiographic sensitivity is defined as what
The smallest discontinuity which can be detected using a penetrameter
What determines radiographic sensitivity
Contrast and definition (detail) of the penetrameter
Contrast in a radiograph is the difference in what
Resultant density which is produced for a given change of x-ray absorption
What are The factors that affect object contrast
Material contrast,
thickness variation,
quality of radiation,
scatter radiation
What are factors that affect imaging plate resolution/film contrast
- Type of film/development of film,
- density,
- for CR this is adjusted using the W/L (window/level) settings.
Kilovoltage is determined by what
The thickness and composition of the material being inspected
