Abstract: A metering system for the coating of webs of paper and cardboard uses a doctor bar received in an elastic bed which is urged toward the surface to be coated by a pressurizable bladder subdivided into compartments. An elastic continuous member between the diaphragm and the bed equalizes the pressure so that sudden changes in pressure in the regions between the compartments are eliminated.

Abstract: In the two-sided coating of a web by feeding the web through the nip of a pair of pressing rolls onto which the coating substance is metered, the amount of the coating substance applied to each pressing roll is measured by infrared absorption and the relative coating quantities RW.sub.o onto the upper side and RW.sub.u to the underside are calculated by the relationsRW.sub.o =M2.sub.o /(M2.sub.o +M2.sub.u) andRW.sub.u =M2.sub.u /(M2.sub.o +M2.sub.u); andwhere M2.sub.o represents an infrared absorption measurement of the coating on the roll applying the coating to the upper side and M2u represents the absorption measurement of the coating on the roll applying the substance to the underside of the web.