
Standard Test Method for Measurement of Retroreflective Signs Using a Portable Retroreflectometer at a 0.2 Degree Observation Angle
出版:American Society for Testing and Materials

專家解讀視頻
Standard Test Method for Measurement of Retroreflective Signs Using a Portable Retroreflectometer at a 0.2 Degree Observation Angle
出版:American Society for Testing and Materials
專家解讀視頻