ASTM E2597-07e1
(Practice)Standard Practice for Manufacturing Characterization of Digital Detector Arrays
Standard Practice for Manufacturing Characterization of Digital Detector Arrays
SIGNIFICANCE AND USE
This practice provides a means to compare DDAs on a common set of technical measurements, realizing that in practice adjustments can be made to achieve similar results even with disparate DDAs given geometric magnification, or other industrial radiologic settings that may compensate for one shortcoming of a device.
A user must understand the definitions and corresponding performance parameters used in this practice in order to make an informed decision on how a given DDA can be used in the target application.
The factors that will be evaluated for each DDA are: basic spatial resolution (SRb), efficiency (Detector SNR-normalized (dSNRn) at 1 mGy, for different energies and beam qualities), achievable contrast sensitivity (CSa), specific material thickness range (SMTR), image lag, burn-in, bad pixels and internal scatter radiation (ISR).
SCOPE
1.1 This practice describes the evaluation of Digital Detector Arrays (DDAs), and assures that one common standard exists for quantitative comparison of DDAs so that an appropriate DDA is selected to meet NDT requirements.
1.2 This practice is intended for use by manufacturers or integrators of DDAs to provide quantitative results of DDA characteristics for NDT user or purchaser consumption. Some of these tests require specialized test phantoms to assure consistency among results among suppliers or manufacturers. These tests are not intended for users to complete, nor are they intended for long term stability tracking and lifetime measurements. However, they may be used for this purpose, if so desired.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation: E2597 − 07
StandardPractice for
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Manufacturing Characterization of Digital Detector Arrays
This standard is issued under the fixed designation E2597; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
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´ NOTE—Editorial corrections were made throughout in April 2008.
1. Scope E2445PracticeforQualificationandLong-TermStabilityof
Computed Radiology Systems
1.1 This practice describes the evaluation of Digital Detec-
E2446Practice for Classification of Computed Radiology
tor Arrays (DDAs), and assures that one common standard
Systems
exists for quantitative comparison of DDAs so that an appro-
2.2 Other Standards:
priate DDA is selected to meet NDT requirements.
ISO7004 Photography—Industrial Radiographic Films—
1.2 This practice is intended for use by manufacturers or
Determination of ISO Speed, ISO Average Gradient and
integrators of DDAs to provide quantitative results of DDA
ISO Gradients G2 and G4 When Exposed to X- and
characteristics for NDT user or purchaser consumption. Some 3
Gamma-Radiation
of these tests require specialized test phantoms to assure
IEC 62220-1Medical Electrical Equipment Characteristics
consistency among results among suppliers or manufacturers.
ofDigitalX-rayImagingDevicesPart1:Determinationof
These tests are not intended for users to complete, nor are they 4
the Detective Quantum Efficiency
intended for long term stability tracking and lifetime measure-
ments. However, they may be used for this purpose, if so
3. Terminology
desired.
3.1 Definitions of Terms Specific to This Standard:
1.3 The values stated in SI units are to be regarded as
3.1.1 digital detector array (DDA) system—an electronic
standard. The values given in parentheses are for information
device that converts ionizing or penetrating radiation into a
only.
discrete array of analog signals which are subsequently digi-
tized and transferred to a computer for display as a digital
1.4 This standard does not purport to address all of the
image corresponding to the radiologic energy pattern imparted
safety concerns, if any, associated with its use. It is the
upon the input region of the device. The conversion of the
responsibility of the user of this standard to establish appro-
ionizing or penetrating radiation into an electronic signal may
priate safety and health practices and determine the applica-
transpire by first converting the ionizing or penetrating radia-
bility of regulatory limitations prior to use.
tionintovisiblelightthroughtheuseofascintillatingmaterial.
2. Referenced Documents
These devices can range in speed from many seconds per
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2.1 ASTM Standards: image to many images per second, up to and in excess of
real-time radioscopy rates (usually 30 frames per seconds).
E1316Terminology for Nondestructive Examinations
E1647Practice for Determining Contrast Sensitivity in Ra-
3.1.2 active DDA area—the size and location of the DDA,
diology
which is recommended by the manufacturer as usable.
E1742Practice for Radiographic Examination
3.1.3 signal-to-noise ratio (SNR)—quotient of mean value
E1815Test Method for Classification of Film Systems for
of the intensity (signal) and standard deviation of the intensity
Industrial Radiography
(noise). The SNR depends on the radiation dose and the DDA
E2002PracticeforDeterminingTotalImageUnsharpnessin
system properties.
Radiology
3.1.4 contrast-to-noise ratio (CNR)—quotient of the differ-
enceofthemeansignallevelsbetweentwoimageareasandthe
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This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
standarddeviationofthesignallevels.Asappliedhere,thetwo
structive Testing and is the direct responsibility of Subcommittee E07.01 on
Radiology (X and Gamma) Method.
Current edition approved Dec. 1, 2007. Published January 2008. DOI: 10.1520/
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E2597-07E01. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4th Floor, New York, NY 10036, http://www.ansi.org.
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Standards volume information, refer to the standard’s Document Summary page on Varembé, Case postale 131, CH-1211, Geneva 20, Switzerland, http://www.iec.ch.
the ASTM website.
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E2597 − 07
image areas are the step-wedge groove and base material. The 3.1.19 phantom—apartoritembeingu
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