An apparatus and method for determining the degree of engagement between a clothes mover and fabric items during a wash process, and a method for setting the liquid level in the automatic washer based on the degree of engagement between a clothes mover and the fabric items. The method includes profiling an executable of the software application to generate application call trees. An external oscillator initiates reciprocating motion in the armature of a linear alternator. In particular, the combination of treatments leads to a more improved effect of water treatment. Each of the plurality of device interfaces includes at least one hardware selection switch to configure the respective device interfaces for either read and write mode or read-only mode. Therewith non-flammability of the heat insulator is ensured and a refrigerator box prevented from catching an outside caused fire is achieved, thus a refrigerator which is safe even when a flammable refrigerant is used and which is high in energy-saving is provided.