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Author(s) -
Coates E.,
Durrans J.,
Rigg B.
Publication year - 1970
Publication title -
journal of the society of dyers and colourists
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 49
eISSN - 1478-4408
pISSN - 0037-9859
DOI - 10.1111/j.1478-4408.1970.tb02955.x
Subject(s) - sample (material) , sorting , mathematics , point (geometry) , colour difference , colored , optics , statistics , computer science , materials science , chemistry , composite material , physics , chromatography , geometry , algorithm
Two sets of industrially dyed 8‐oz fabric, one (green cotton) containing 46 pieces that had been visually sorted into five batches and the other (blue cotton‐Terylene) 30 pieces, sorted into three batches at the production stage, have been measured colorimetrically. Two instruments (the Signature Model Color‐Eye and the Colormaster Model V) have been compared for precision in use consistent with speed, and the latter was favoured. Two ends from each piece were available and the best procedure for measurement was determined, taking into account the variations in colour across and along the piece. One measurement on four thicknesses of any specimen from an end of a piece is satisfactory, measured behind plain glass in a rotating‐head, four specimens from each end being required to provide suitable average results for a piece. A consistent set of results for many pieces measured over several hours can best be obtained by the use of one specimen as a reference sample. Repeat measurements on the reference sample, every 30 min, enable the results for all pieces to be related by colour‐difference measurements to a fixed point for the reference sample. This procedure compensates for significant variations in measured results for any specimen taken over periods longer than 15 min. There are insignificant variations in colour differences for a given pair of specimens over long periods when the pair are measured within a short period (ca 15 min). The instrumental results are consistent with the visual assessments and could be used for instrumental sorting. The colour variations among these pieces are essentially due to strength variations, and additional systems showing more random colour variations must be studied before a comprehensive sorting procedure can be considered.