Abstract: An apparatus for measuring the weight of impurities in a cotton sample, with a double-taker-in-roll mechanism. The apparatus includes the following components: an air current channel, a fiber feeding device located at the front end of the air current channel; a primary taker-in cylinder located behind the fiber feeding construction; a stationary stripping device located near the surface of the primary taker-in cylinder; a secondary taker-in cylinder adjacent to the surface of the primary taker-in cylinder and located behind the primary taker-in cylinder; an impurity collecting apparatus located below the primary taker-in cylinder and the secondary taker-in cylinder; and an impurity measurement apparatus connected with the impurity collecting apparatus.

Abstract: A method for measuring the weight of impurities in a mixed volume of fibers and impurities by mechanically separating the impurities are from the fibers, whereupon some undesired fibers still remain admixed to the impurities due to imperfections of the mechanical separation. A total weight of the separated impurities and the undesired fibers is gravimetrically measured. An image of the separated impurities and the undesired fibers is created. A weight of the undesired fibers is estimated from the image. The estimated weight of the undesired fibers is subtracted from the total weight to yield a corrected weight of the impurities. The mechanical separation and the subsequent electronic correction yield a more accurate weight of the impurities.