Because web weight uniformity is critical in the manufacture of nonwoven fabrics, there is currently a great demand for an online noncontact continuous base weight monitoring system for nonwoven fabrics process lines. Such optical methods as the charge coupled device (CCD) line scan camera, and the laser scanner have proven effective in measuring base weight quality in the manufacture of paper and nonwoven fabrics. The CCD linescan camera and the laser scanner are reported to be successful in the online monitoring of nonwovens. Experimental data suggest that a CCD linescan camera is effective in calibrating the weight of fiber tufts moving in an air duct. Results indicate that there is a linear relationship between the sum of light transmission values and the fiber tuft weights for both cotton and acrylic samples, and that constant fiber tuft speeds occur in air ducts featuring a stable air flow. An increase in the degree of fiber opening results in greater scanner accuracy.