A linear density indicator is provided by the Spinlab HVI 900 system which is used to normalize the breaking load measurement to units of gf/tex. The indicator of mass or tex of those fibers spanning the region between clamping jaws is referenced to the light attenuation at a selected position on the beard and linearly corrected for micronaire. Although micronaire is a useful and realistic factor of correction, it has been found that mean fineness as determined by Suter-Webb array methods gives higher correlation.