Abstract: Two coils between which a sample is contactlessly held in a suspended state, form a common part of two different oscillating circuits. A heating oscillating-circuit consists of the two coils and two first capacitors. A positioning oscillating-circuit consists of the two coils and two second capacitors. The current of the heating oscillating-circuit flows through both coils in the same direction, and the current of the positioning oscillating-circuit flows through both coils in opposite directions. Since the two oscillating circuits are not coupled to each other, heating efficiency and positioning efficiency can be set independently from each other. Two coils are sufficient for heating and positioning.

Abstract: Two coils, between which a sample is kept in a contactless suspended state, are connected to separate power sources, at least one of which comprises a phase shifter. Both power sources are controlled by a common oscillation generator. If both currents in the coils are in phase, a magnetic dipole-field of high heating capacity is obtained. If the two currents in the coils are in counterphase, a quadrupole-field is obtained, which generates a high positioning force. By modifying the phase difference, it is possible to generate optional superpositions of the dipole-field and the quadrupole-field, whereby the parts of heating capacity and positioning capacity can be varied.