Setting up an Exposure (8) Flashcards
1
Q
Factors impacting type of radiation technique:
A
- client’s and specifications requirements
- pipe diameter
- wall thickness
- required sensitivity
2
Q
Radiation techniques in two categories:
A
- single/double wall exposure (radiation travels through one or two wall thicknesses)
- single wall of double wall viewing (one or both walls of the tubular section is visible on radiograph)
3
Q
Radiation Techniques
A
- contact exposure (double wall exposure with single wall view)
- superimposed exposure (double wall exposure with double wall view)
- elliptical exposure (double wall exposure with double wall view)
- panoramic or circumferential exposure (single wall exposure with single wall view)
- IQI on film side
4
Q
Contact Exposure
A
- double wall exposure with single wall viewing
- radiation source placed against specimen
- shielded with a collimator
- only back wall can be viewed
- cassette is wrapped
5
Q
Superimposed exposure
A
- double wall exposure with double wall view
- radiation source placed a distance away from specimen (according to specifications)
- shielded with collimator
- wrapped cassette
- used for small pipes (<3.5in diameter)
- edit/superimpose portions of weld on top of one another
- need markers
- IQI on source side
- 2-3 exposures (60°-120° from each other)
6
Q
Elliptical exposure
A
- double wall exposure with double wall viewing
- radiation source placed a distance away from specimen at on angle (15°-30°)
- flat cassette
- small pipes (<3.5in diameter)
- need markers
- 2-3 exposures
7
Q
Panoramic or Circumferential exposure
A
- single wall exposure with single wall viewing
- whole weld 1 exposure
- large pipes/vessels
- wrapped film’s
- radiation source centered inside specimen
8
Q
other single wall exposure with single wall viewing techniques
A
- far away outside, cassette wrapped inside
- far away inside, cassette wrapped outside
