NC State
R.J. Hall. Instrumental quantification of subjective formation. In The Fundamental Properties of Paper Related to its Uses, Trans. of the Vth Fund. Res. Symp. Cambridge, 1973, (F. Bolam, ed.), pp 662–677, FRC, Manchester, 2018.


The means of defining formation in terms of its subjective appearance was explored by processing the transmitted light signal from various paper samples on an analogue computer using equations related to physiological attributes. Some psychological aspects of the interpretation of images are discussed and the relevant aspects of both of these is described. It is demonstrated how this approach was implemented in an instrumental technique to quantify hitherto subjective assessments of quality.

The statistical significance of the aspects of microformation and macroformation is explained and practical analysis is achieved by dissecting an area into strips. The value of each strip is derived from the content of the microformation, these values are then analysed for mean and standard deviation to assign numbers for both the microformation and macroformation. The instrument outputs a weighted value of the sum of the two figures on a continuous sampling basis.

The instrument has been used in the laboratory for sample testing,in particular cigarette tissue, also on a papermachine making tracing paper, where a continuous record is produced.

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