Standard Practice for Performance Evaluation and Long-Term Stability of Computed Radiography Systems

Importancia y uso:

4.1 This practice is intended to be used by the NDT using organization to measure baseline performance of the CR system and to monitor its performance throughout its service as an NDT imaging system. For purposes of this document, the CR System is defined as:

4.1.1 Storage phosphor imaging plate (IP) type and manufacturer,

4.1.2 Read out unit (scanner or reader) manufacturer and model, including applicable scanner settings (for example, sampling resolution, PMT gain, pixel value (PV) look up table, etc.),

4.1.3 Image acquisition and processing software, and

4.1.4 Image display monitor.

4.2 It is to be understood that the CR system has already been selected and purchased by the user from a manufacturer based on the inspection needs at hand. The user shall accept the CR scanner based on manufacturer’s results of Practice E2446 on the specific CR scanner as provided in a data sheet for that serialized CR scanner or other acceptance test agreed to between the user and manufacturer (not covered in this practice). This practice is not intended to be used as an “acceptance test” of the CR system, but rather to establish a performance baseline that will enable tracking while in-service.

4.3 Although many of the properties listed in this standard have similar metrics to those found in Practice E2446, data collection methods are not identical, and comparisons among values acquired with each standard should not be made.

4.4 This practice defines the tests to be performed and required intervals. Also defined are the methods of tabulating results that CR users will complete following the baseline of the CR system. These tests will also be performed periodically at the stated required intervals to evaluate the CR system to determine if the system remains within acceptable operational limits as established in this practice.

4.5 There are several factors that affect the image quality of a CR image. Factors which are dependent on the CR system performance include basic spatial resolution, relative contrast, and signal-to-noise ratio (SNR) which yield the contrast sensitivity (CS) and Equivalent Penetrameter Sensitivity (EPS). There are several additional factors that are dependent on how well the CR system is functioning (that is, resulting from normal wear and tear, inadequate maintenance, improper setup/calibration, etc.), such as slippage, laser jitter, geometric distortion, etc. Other factors which are related to the specific applications (for example, geometric unsharpness, scatter, etc.) are not evaluated in these tests.

Subcomité:

E07.01

Referida por:

E1161-21, E0094_E0094M-22, E0543-21, E3327_E3327M-21, E2533-21, E0543-21, E2982-21

Volúmen:

03.04

Número ICS:

19.100 (Non-destructive testing)

Palabras clave:

basic spatial resolution; burn-in; central beam alignment; contrast sensitivity; CR phantom; EPS; erasure; geometric distortion; imaging plate artifacts; imaging plate fading; laser beam scan line integrity; laser jitter; PMT non-linearity; scan column dropout; scanner slippage; spatial linearity;