BS 5477 77th Edition, June 30, 1977
Method for Visual assessment, by grid assay, of dirt in paper for character recognition
Includes all amendments and changes through Reaffirmation Notice , September 2, 2013
Published By:British Standards Institution (BSI)
Measures the proportion of the surface area containing particles that are immediately obvious to the eye. Reports the number of grid squares per 6 m2 containing dirt.