An air conditioning compressor for air conditioning systems in motor vehicles, wherein the air conditioning compressor at the high pressure output comprises a check valve and a pressure control device, for example a pressure control valve or a bursting disk. The drying unit heats and dries the web with a heater block, to thereby stabilize the water-content of the web in an absolute dry region which is a lower water-content region as compared with a normal water-content region. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. There is then a group of four 4\xd74 sets of sub-regions, then a group of sixteen 2\xd72 sets of sub-regions, and finally a layer comprising the 64 single sub-regions. The instructing signal input portion includes at least a noise reducing circuit which reduces a normal-mode noise. The coating is stable over a wide pH range and allows highly efficient grafting andor adsorption of a variety of additional layers, if desired.