What is the formula for calculating radiographic sensitivity?
The diameter of the smallest hole visible on the radiograph determines the sensitivity, this being calculated as hole diameter divided by component thickness expressed as a percentage. The sensitivity measured by the use of a wire IQI is not the same as the sensitivity using a step wedge IQI.
What is radiographic sensitivity?
In industrial radiography, Radiographic Sensitivity is a QUALITATIVE term referring to the size of the smallest detail that can be recorded and discernible on the film/radiograph, or to the ease with which the images of small details can be recorded.
What is 2 2T sensitivity?
The meaning of 2/2T is simply, 2 refers the Image Quality indicator thickness is 2% of the specimen thickness, and 2T is our required Sensitivity level (2T hole must be seen). But all the Hole type IQIs thickness are not exactly 2% of the test specimen thickness.
How is SFD calculated in radiography?
SFD : Minimum SFD is to be calculated using the SFD equation. Thumb rule, 10 times the object thickness and 1.1 X length of the film, which is greater. Recommended minimum SFD is 18”.
What is the formula for geometric unsharpness?
Ug = F (t / d)
What is FFD in radiology?
FFD (Focal Film Distance) The distance between the x-ray tube and the film. Increasing or decreasing this distance will have an effect on radiographic density. Focal spot. The particular area that the electron beam is aimed at on the tungsten target.
What are primary protective barriers?
Primary protective barrier means the material, excluding filters, placed in the useful beam. Primary protective barrier means the material, excluding filters, placed in the useful beam to reduce the radiation exposure (beyond the patient and cassette holder) for protection barriers.
What are primary and secondary barriers?
There are two levels of biological containment—primary and secondary. Primary containment protects people and the immediate laboratory environment from exposure to infectious agents. Secondary containment protects the environment external to the laboratory from exposure to infectious materials.
Which of the following is an example of a primary barrier?
Examples of primary barriers include safety equipment such as biological safety cabinets (BSCs), enclosed containers, and safety centrifuge cups.
What do you mean by primary barrier?
Primary barriers are both techniques and equipment that guard against the release of biological material; they may also be referred to as primary containment. In general, they provide a physical barrier between the worker and/or the environment and the hazardous material.
What is primary barrier in radiation?
Primary barrier is the barrier in which the primary beam of the treatment machine falls (Linac, co-60 units) on it. The thickness of the primary is greater than the other barriers of room. Shielding materials for primary barrier as well as other barriers are same like concrete, lead, and steel etc.
What is a secondary barrier?
The liquid-resisting outer element of a cargo containment system designed to ensure temporary containment of any envisaged leakage of liquid cargo through the primary barrier and to prevent the lowering of the temperature of the ship structure to an unsafe level.
Which radiation barrier is thicker?
For photons (x-rays, gamma rays) the lower the atomic number of the shield, the thicker it must be. For neutrons, the general rule is that the lower the hydrogen content, the thicker the shield must be.
What thickness of lead is required for a secondary barrier?
In most cases the leakage radiation is much less than this limit. lead sheets 1/32 of an inch thick, gypsum board, lead glass, or lead acrylic. Walls that are considered secondary protective barriers may be constructed with four layers of 5/8-inch gypsum board.
Why is the control booth barrier considered a secondary protective barrier?
Protective barriers are lined with lead to protect personnel and the general public from radiation. The walls that are not in the direct line of travel of the primary beam are called secondary protective barriers because they are designed to shield against secondary (leakage and scattered) radiation.
What is an appropriate thickness for protective barrier?
The wall thickness around the diagnostic room was measured to be 3.0 x 102 mm. This shows that the protective shielding thickness is adequate compared to the international recommended standard value of 74.0 ± 7.4 × 10-1 mm even for the highest peak voltage.
What is work load and occupancy factor?
Briefly describe (a) Workload (b) Use factor (c) Occupancy factor. (c) Occupancy factor (T)- indicates the fraction of time a particular place is occupied by staff, patients or public. e.g work area, offices staff room (T=1), corridors, employee lounge (T=1/5), Toilets, unattended waiting room (T=1/20) etc.