The invention provides a system in which, in a case where an event requiring a user operation occurs on a mobile terminal side, a printer can continue the print processing even if the terminal is moved outside the range of short distance communication by paying in advance a print fee to the printer. The method includes providing a chamber having within it molten metal and a gaseous atmosphere above the molten metal, providing at least one reducing gas container proximate the interface between the molten metal and the gaseous atmosphere, providing a source of a reducing gas, and directing the reducing gas to the at least one container. The disclosure further relates to an apparatus that is suitable for carrying out the method. The piston member is preferably provided with a single seal gasket that prevents leakage of gas towards the outside through the sliding coupling of the piston member within the respective guide bushing. A service department ID is extracted from the database based on the accessing results.