GB/T 15972.46-2008 Focused optical fiber test, for optical fiber transmission and Optical inspection characteristics of light transmitance changes. Measurement principles are clearly defined in this standard, and the required equipment is introduced. Measuring methods are described in detail, including how to select measurement points and set Measurement conditions. Specify complete test procedures, from preparation to data collection, processing and result determination, and give specific operating specifications. Provide uniform criteria for accurate measurement of optical fiber light transmitance changes, and help ensure the Reliability and Stability of optical fiber performance in areas such as optical fiber communication.