The method detects variations of the torque of a DC motor and is particularly suited for detecting an accidental block of the motor operation. The structure comprises a first semiconductor zone with a first type of conductivity with a first longitudinal face, said first zone being made of mercury-cadmium telluride of the CdxHg1-xTe type with a cadmium proportion x that is varied. A fluorinated hydrocarbon containing stream, a polymer product stream and a waste stream are recovered from the mixture. The second laser signal may be from an external source, or may be a frequency-multiplied version of the generated supercontinuum. The apparatus includes: a needle for core insertion inserted into the drilled core to allow the gas in the drilled core to the outside; and a first 3-way valve into which the gas passing through the needle for core insertion is introduced and which controls the introduced gas so as to be supplied to a gas storing container or gas analyzing apparatuses positioned on a ship. Each second electrode set comprises two third electrodes and a fourth electrode disposed between these third electrodes.