A line system for fluids having volatile components, which comprises at least one fluid line, each having a separate inlet and outlet, the fluid lines being enclosed by a first line wall and extending jointly over a section of the line system close-fitting to one another, but being separated from one another at least by the first line wall over the entire length of the fluid lines. The luminescing substance comprises a fluorescent compound have a fluorescent maximum at about 540 nm or above and a compound having a pyrromethene structure or metal complexes thereof. The thus hexagonally formed lens holder has advantageous air chambers and an enlarged distance from the lens, and also an elastic support deviating from a parallel guide, which lead to a low degree of lens tilting, improved guidance properties and a natural resonance behaviour which is necessary for scanning at high speed. If the secure device currently does not have the necessary software to execute the command, the command is delayed and the proper software is loaded from the non-secure portion to the RAM of the secure device. The said membrane is used for medical purposes, especially for the haemodialysis, haemofiltration, haemodiafiltration, plasmapherese, immunotherapy, micro- or ultrafiltration or gas separation. The arrangement comprises a charging circuit comprising a first diode and a second diode connected in series with the first diode and a current-limiting component connected in parallel with the series connection of the diodes, whereby said capacitors may be charged through a main switch of the capacitor, the first diode and the current-limiting component.