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Report of the Oil Color Committee—1948
Author(s) -
Thomson Procter,
Stillman R. C.
Publication year - 1949
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02902781
Subject(s) - reproducibility , standard deviation , transmittance , reliability (semiconductor) , analytical chemistry (journal) , mathematics , statistics , materials science , chemistry , chromatography , physics , optoelectronics , thermodynamics , power (physics)
Conclusions The data completed on oils and on nickel sulfate solutions indicate that there is a standard deviation of up to 2% transmittance between measurements made by different laboratories on different instruments. This standard deviation is decreased by one‐half when measurements are made by a single laboratory on a single instrument. The data indicate that nickel sulfate may be a satisfactory solution to use in standardizing the instruments in use in the various laboratories. The results obtained on the 12 oils submitted for readings indicate that about the same degree of reliability is obtained spectrophotometrically as with the Lovibond system at low color levels. At high color levels the spectrophotometer shows considerably more reproducibility. It is impossible to tell from the data obtained whether a single number system, such as a density measurement of 550 mμ., or a color index value, consisting of some function of measurements at two or more wavelengths, would be the most suitable for general measurements.