When a reset signal RESET is \u201cL\u201d, a flip-flop circuit holds \u201c1\u201d; on the other hand, a flip-flop circuit holds \u201c0\u201d. According to the invention, at least one stirring element is immersed at least partly in a sample to be heated, said stirring element comprising a magnetic or magnetisable material. The memory device includes a select gate and a floating gate, and the select gate and the floating gate are disposed adjacently on the substrate in the memory region. A passageway extends from the forward tuning volume to an opening in the housing. A pocket is formed in the carrier substrate, and the chip that was removed is placed into the pocket formed in the carrier substrate.