
8. Glossary
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Piranha & QABrowser Reference Manual
Exposure (X)
A measure of the quantity of X-ray or gamma radiation based upon its ability to ionize
air through which it passes. The SI unit of exposure is coulomb per kilogram. The
previously used special unit of exposure was röntgen (R). 1 R = 2.58 × 10
-4
C·kg
-1
(exactly). The physical quantity exposure is now replaced by
the quantity kerma in air. An exposure of 114.1 R is equal to an Air Kerma of 1 Gy. That
means that the value in R should be multiplied by 8.76 to get the Air Kerma in mGy.
SI unit: C/kg
Exposure rate (X')
Exposure per unit time. Exposure rate is determined as the quotient of dX by dt, where
dX is the increment of exposure in the time interval dt: X' = dX/dt. A unit of exposure
rate is any quotient of the unit of exposure or its multiples or submultiples by a suitable
unit of time ((C/kg)/s, (mC/kg)/h, etc.).
SI unit: C/kg·s
Filter
In radiological equipment, material or device provided to effect filtration of the radiation
beam.
SI unit: mm
Filter: Inherent filter
The filter permanently in the useful beam; it includes the window of the X-ray tube and
any permanent enclosure for the tube or source. Replaced by term Permanent filter
Filter: Added filter
Filter in addition to the inherent filtration.
Filter: Permanent filter
The filter permanently in the useful beam; it includes the window of the X-ray tube and
any permanent enclosure for the tube or source.
Filter: Total filter
The sum of the permanent and added filters.
Firmware
General: The operating system and software installed on a small device. Sometimes
called embedded software.
Piranha firmware: Program stored in cabinet and modules which handles all control of
measurement electronics. Can be updated, then a special part of the firmware called
bootloader, is used. See Bootloader.
Fluorography
The production of a photographic record of the image formed on the output phosphor of
an image intensifier by the action of X-rays transmitted through the patient.
Fluoroscopy
Technique of radioscopy by means of a fluorescent screen.
Focal spot, effective
The apparent size of the radiation source region in a source assembly when viewed
from the central axis of the useful radiation beam.
SI unit: dimensionless (corresponding to a dimension in mm)
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Страница 8: ...Introduction Chapter 1 ...
Страница 12: ...Description of the Piranha Chapter 2 ...
Страница 29: ...2 Description of the Piranha Hardware and Specifications 2014 06 5 5C 25 Piranha QABrowser Reference Manual ...
Страница 40: ...Description of the QABrowser Chapter 3 ...
Страница 77: ...Measurement Principles Theory Chapter 4 ...
Страница 91: ...Measurements with the Piranha System Chapter 5 ...
Страница 151: ...Optional Accessories Chapter 6 ...
Страница 154: ...6 Optional Accessories Piranha Panoramic Holder Piranha QABrowser Reference Manual 2014 06 5 5C 150 ...
Страница 155: ...Problems and Solutions Chapter 7 ...
Страница 161: ...Glossary Chapter 8 ...
Страница 181: ...Notes Piranha QABrowser Reference Manual 2014 06 5 5C Notes 177 ...