A method of separating a polymer-solvent mixture is described wherein a polymer-solvent mixture is heated prior to its introduction into an extruder comprising an upstream vent andor a side feeder vent to allow flash evaporation of the solvent, and downstream vents for removal of remaining solvent. The holder is pivotably mounted relative to the shank and can be fixed in any respective position which is reached by pivoting. A second alignment data setting unit sets second alignment data, which represents a difference angle in the azimuth direction between the sensor coordinate system and reference coordinate system in the orientation calculation unit in accordance with a command input by an operator from a command input unit.