The invention relates to a method for online correction of non-linearities in the imaging system during the data acquisition in industrial computer tomography. The pores can comprise at least two sections, or steps, in which the thickness of the membrane is reduced in stepwise fashion, or the pores can be tapered. The appliqu\xe9s adhere to the rear panels of the folding chair using the attachment mechanism, which may be either a magnetic layer or a plurality of adhesive strips. These pendant groups can also be reacted to contain functional end groups such as hydroxyl and epoxy.