2—Air Flow Through Plugs of Textile Fibres

A study is made of the various factors influencing the values obtained from Micronaire tests made on samples of cotton. It is shown that both fibre fineness and maturity affect the measurements and a calibration of the scale of the instrument is made in terms of a simple function of these two quantities. The interpretation of Micronaire results is discussed. Applications of the test to mill checking of cotton quality, and to cotton breeding, are considered with particular reference to the problems arising from the dependence of Micronaire test values on fibre fineness and maturity. The nature of variation in Micronaire values associated with particular aspects of test procedure, and with differences occurring between samples, between bales and within bales, is investigated in detailed statistical appendices. Estimates are given of the values of standard deviation associated with the different sources of variance.