Abstract: A fluororesin-coated electric wire cable is wound around a ring-shaped groove defined by an outer periphery of a cylinder and two flange edges immersed in an edible oil in a tank, forming each oscillating unit having a coil part; and the oscillating units are connected to an electromagnetic wave generator through a relay unit. Electromagnetic waves are irradiated from the coil parts based on an alternating current having a single frequency, an alternating current having a plurality of single frequencies different from one another, or an alternating current having a timewise varying frequency, the alternating currents each being within a frequency band of 4 kHz to 25 kHz, and a treatment based on a far-infrared heater or far-infrared ceramic is used combinedly therewith, to prevent deterioration of an edible oil or industrial oil.

Abstract: A fluororesin-coated electric wire cable is wound around a ring-shaped groove defined by an outer periphery of a cylinder and two flange edges immersed in an edible oil in a tank, forming each oscillating unit having a coil part; and the oscillating units are connected to an electromagnetic wave generator through a relay unit. Electromagnetic waves are irradiated from the coil parts based on an alternating current having a single frequency, an alternating current having a plurality of single frequencies different from one another, or an alternating current having a timewise varying frequency, the alternating currents each being within a frequency band of 4 kHz to 25 kHz, and a treatment based on a far-infrared heater or far-infrared ceramic is used combinedly therewith, to prevent deterioration of an edible oil or industrial oil.

Abstract: A soldering method in which, out of soldering steps of (a) during soldering, (b) before soldering, and (c) after soldering, in at least the steps of (a) during soldering and (b) before soldering, an alternating current whose frequency temporally changes in a band of 20 Hz-1 MHz is applied to at least any of (d) a solder material, (e) a soldering object, and (f) a peripheral portion thereof, and a modulated electromagnetic wave treatment is carried out by use of an electromagnetic field induced by the alternating current. Thereby, when not only a lead-containing solder material but also a lead-free solder material are used, wettability in soldering to a soldering object is made better, and an obtained soldered article is improved in strength, etc., compared to the conventional solder material.