GB/T 21355-2008

This standard specifies the evaluation and classification methods for computer radiography (CR) systems, which include: special phosphor imaging plates (IP), system scanners, and software, as well as special metal intensifying screens for use in industrial radiography detection. The purpose is to evaluate the impact of the detector/IP system to ensure imaging quality and meet user requirements. The system classification test methods specified in this standard are applicable to different suppliers and can also provide users with comparability of different systems. The performance of CR systems is characterized by signal and noise parameters. For film systems, the signal is represented by gradation, and the noise is represented by graininess. The normalized signal-to-noise ratio is a component of the classification of CR systems, which is represented by the basic spatial resolution of the system. The standardized test method can be carried out according to the provisions of GB/T 19348.1 (Classification of Film Systems), that is, by scanning with a beam emitted from a 100μm diameter aperture of a microdensitometer. This standard describes how these parameters of CR systems should be measured.