In order to lease threads, in particular warp threads into guide elements of a handling device, such as combs or reeds, the threads are first leased in sequence into a leasing comb and are fixed thereto. The amplifier is filterless and DC free. The apparatus also includes a bag-supporting portion configured to support an open end portion of a flexible plastic bag thereon, the bag-supporting portion including an outer loop portion and a downwardly-extending short portion attached to the outer loop portion at each end thereof. If key system files are found cannot be verified upon a reboot, a copy of key system file is sought. The central controller is used to adjust the composition of the slurry in the slurry supply tub and the polishing condition of the polishing table according to the oxidant concentration of the slurry obtained from a signal transmitted by the spectrometer.