Laboratory research as well as field evaluation in 1989 indicated that color/trash meters similar to those used in the cotton classing system in the United States could be used in the gin to monitor the color and trash in cotton during gin processing. The purpose of the evaluation in 1990 was to establish the durability of the meters in the harsh gin environment, and to evaluate their correlation with similar laboratory measurements. In 1990, two Motion Control, Inc. Color/Trash meters were again installed at a commercial gin at Burdette, MS, in the second year of a multi-year study. One meter was installed above the extractor-feeder adjacent to a holding chamber. The other meter was installed in a specially constructed device that extracted lint from the lint flue, measured its color and trash, then returned the lint to the lint flue. The device at the lint flue was replaced at mid-season with a simple, valve-type device that captured a lint sample, compressed it against the camera glass, triggered the computer to record a measurement, and released the lint. Initial and daily calibration of the meters was accomplished by using standard manufacturers techniques which include the use of a black box, a color tile, and a trash tile for references. Compression devices were also installed to increase the surface density of the cotton to enhance color and trash measurements. The devices also triggered the computer to take readings when maximum compression was achieved. The camera and power supply portions of the meters were installed in the gin system, while the computer, multiplexor board, analog-to-digital board, frame-grabber board, and the video monitor were installed in the office. No problems were encountered with any of the experimental systems in 1990 with the interaction between the two cameras and the triggering apparatus, and the fluctuations in voltage in the ginning system were solved in 1990. Reference samples collected during the ginning season and evaluated by the High Volume Instrument classification system for cotton indicated substantial relationships between laboratory measurements and measurements taken at the gin. Based on field evaluations, it appears that color/trash meters can perform satisfactorily in the ginning system, but improvements must be made in the correlation between laboratory and field measurements.