Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
65 Cards in this Set
- Front
- Back
Why is an exposure chart designed?
|
To provide detailed exposure technique for a material of a given thickness which will produce a pre determined density.
|
|
exposure charts are sometimes called what?
|
constant density or technique chart.
|
|
Set of guidelines used to establish uniformity?
|
parameters
|
|
vary from chart to chart?
|
variables
|
|
What are the different variables for exposure charts?
|
exposure, kV range, and material thickness
|
|
Must be listed on the chart?
|
Constants
|
|
What are the different constants?
|
-type material
-type of machine -type and make of film -HD to be produced -mA used -SFD -quality enhancers -processing method -type of development |
|
What materials are used in the construction of an exposure chart?
|
semi-logarithmic paper and a wedge.
|
|
Prevents lines from curving back onto each other?
|
Semi-logarithmic paper
|
|
What are 4 ways to construct a chart?
|
-Step block
-Step block & characterist curve. -Wedge tappered -Wedge tappered& characteristic curve |
|
Least perfered method of constructing a chart?
|
Step block
|
|
Why is the step block the least perfered method of constructing a chart?
|
Req 4 exposure per kV line, and each exposure taken at different MAS. An you can not always find desired density.
|
|
What is the most accurate way to construct a chart?
|
wedge tappered
|
|
What method do we use in school for constructing exposure charts?
|
wedge tappered & characteristic curve.
|
|
What formula is used to find the thickness of a tappered wedge at a given density?
|
(TANagl x D)+t=T
|
|
Four densities must be selected which will be used for every kV line What are they?
|
First cchoose the constant density, then choose 3 others evenly spacedfrom the constant
|
|
What are some of the factors in selecting film to be used?
|
-Film used most often
-Has good contrast and latitiude -Has characteristic curve available for it. |
|
When using the tappered wedge method how many densities are messured?
|
4 densities(D) from the thinest part of the wedge
|
|
How are the 4 dots ploted on the graph connected?
|
at the most otimum angle
|
|
What is the purpose of a radiographic technique?
|
To provide repatable step by step procedures, giving uniformity.
|
|
Why should radiography only be used if other methods are not avalible?
|
its expensive.
|
|
accounts for a considerable share of the critcal components of an aircraft?
|
Casting
|
|
Defects associated with casting process?
|
-Micro shrinkage
-shringage porosity gas porosity inclusions hot cracks cold shuts misruns dendritics unfused chaplets core shift surface irregularities |
|
Weld discontinuities consist of what?
|
of a change in the materials homoeneity
|
|
Shiny,bright white specks on a radiograph?
|
tungsten inclusions
|
|
Different welding defects and conditions?
|
cover bead, undercutting, splatter, arc tracks and burns,junctions and laps, propsity, slag and wagon tracks, lack of vead fusion, incomplete penetration, burn through.
|
|
What are the different service inspection that can be performed?
|
wear, corr, cracks or crack like defects, water in hunnycomb, FOD, assemblies, and workmenship
|
|
What are the five geometric factors?
|
-Focal spot size
-SFD -beam to film allignment -Film to object distance -object to film alignment |
|
When developing a technique what are the three considerations in order?
|
1st- material type
2nd- material thickness 3rd-lowest practical kV under a 1000 MAS |
|
For Z & L channels how many flanges are computed?
|
one thickness
|
|
For C&I channels how many flanges are computed?
|
TWO
|
|
What is the difference between TPT and TMT?
|
TPT-The thickness of the intire part
TMT-The thickness x rays have to travel. |
|
To shoot a solid part at an angle you have to do what?
|
get the TMT
|
|
if the angle is at 37 degrees what does that mean?
|
the part is 2in or greater
|
|
when do you increase the angle by 5 degrees?
|
For every 1/2in below 2in
|
|
What is the max angle that can be shoot?
|
52 dgrees
|
|
How is the exposure time determined for angle shots?
|
by adding 10% to the final calculated time
|
|
What is the max shift to compensate for angle shots?
|
3in
|
|
Film characteristic curve can also be called?
|
HD curve
LRE chart |
|
LRE chart is designed for?
|
Density corrections, film changes, processing changes
|
|
What does a LRE chart show?
|
The relationship between the exposure applied and the resulting density
|
|
Why do you multiply or divide the ALRV by the original MAS?
|
Do determine the new MAS for the correction or change.
|
|
If you go from a M film to R film what must you do with the ALRV?
|
Multipy because you are going to a slower film
|
|
How do you determine the area of coverage for a larger pice of film?
|
by finding the new SFD.
right the formula down. |
|
How is defect location determined?
|
draw formula
|
|
What is the purpose of multi-thickness overlay?
|
designed to make 1 exposure of a part with various thicknesses.
|
|
The thinnist material on a part will have what?
|
maximum HD on film
|
|
The maximum thickness of the part will have what HD?
|
minimum
|
|
The logarithm of the different LREs multiplied by MAS is used to compue the difference in what?
|
HD for multi thickness
|
|
Can be used to show the thickness range that will be covered by one exposure?
|
Plastic overlay
|
|
For plastic overlay the angle of the kV line used will determine what?
|
The amound of material that can be covered in one exposure at the densityies desired?
|
|
In multi thickness shots as kV increases so does what?
|
thinkness range
|
|
For multi thinkness what line gives you the MAS?
|
2.0 (red)
|
|
If the thickest section cannot be covered in a single exposure you must do what?
|
use multi-film technique
|
|
How is penetrameter size calculated for multi-thickness shots?
|
Follow the 2.0HD over to the nearest kV line and down.
|
|
What does Pre-repair consist of?
|
outline area after visual inspection
Varify outline by tap test Further varify by using other methods available |
|
Whats does post repair inspection consist of?
|
Adhesive/foam splice
Excessive/lack of adhesive |
|
What is the 90 Degree exposure for in BCL inspections?
|
crushed core, corrosion, water intrapment
|
|
Angle exposures in BCL inspections are taken at a max angle of?
|
5 degrees
|
|
A 5 degree angle shot may be used to do what during BCL inspections?
|
blow open cell wall areas and inspect for node seperation.
|
|
May be used to determaing damage extent in advanced composites?
|
5 degree angle shot
|
|
For better contrast in BCL inspections you should do what?
|
Use low kV between 25-75
|
|
What is normal shift of xray tube head?
|
60in SFD- 1in center ray shift
72in SFD-1.25 in 80in SFD-1.4 in |
|
Area of coverage on BCL inspection does what?
|
Allows radiographer to dermine the amount of cell area that will apperar clearly on the radiograph
|
|
What formula is used for determining that area of coverage on BCL.
|
Draw it.
|