Micronaire is used to quickly evaluate the quality of a sample of cotton. It is a measure of air permeability of compressed cotton fibers, which is correlated with fiber fineness and maturity.

The micronaire is based on an arbitrary scale of relative values and does not directly measure any single physical fiber property.


Micronaire Reading

Cotton Quality

>= 5.0


4.3 to 4.9


3.7 to 4.2

premium for yarn making

3.5 to 3.6


<= 3.4



The micronaire reading correlates with the cotton fiber diameter (Figure 5, Montalvo).

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