Abstract: The present invention relates to a process for extracting aromatic dicarboxylic acids from an outlet stream of a basic depolymerization of polycondensates containing metal carboxylates of the aromatic dicarboxylic acid to be extracted, wherein a mineral or organic acid is added to this outlet stream, the pKs value of which acid being greater than or equal to that of the aromatic dicarboxylic acid, on which the polycondensate is based.

Abstract: The invention relates to a method and a device for measuring the distance between a sensor electrode and a workpiece. The sensor electrode forms, with the workpiece, a measuring capacitor through which an alternating current flows. A voltage present at the sensor electrode is tapped as a measuring voltage. In order to be able to remove the disturbing influence on the impedance of the measuring capacitor of a plasma forming between the sensor electrode and workpiece, the real part and the imaginary part from the measuring voltage are analyzed and used to determine the distance between the sensor electrode and the workpiece.

Abstract: The invention relates to a method for temperature compensation of an LC oscillator (8) having a machining head (4) and serving for the capacitive measurement of a distance between the machining head (4) and a workpiece (7), in which an output signal (S) of the LC oscillator (8) is transmitted to an evaluation unit (2) arranged separately from the machining head (4). The temperature (T) of the LC oscillator (8) is measured with the aid of the temperature sensor (29) and supplied to the evaluation unit (2). In the evaluation unit (2), temperature compensation of the output signal (S) of the LC oscillator (8) is effected using the measured temperature (T) and a temperature coefficient (K) which is assigned to the machining head (4) and can likewise be transmitted from the machining head (4) to the evaluation unit (2).

Abstract: The invention relates to a changing device for a lens holder of a connecting head for a laser machining tool. The lens holder includes a focusing optical system arranged therein. The changing device has at least one station including a holder for gripping and holding a lens holder and an actuator for engaging a fastener provided on the connecting head. The fastener fixes and/or releases the lens holder from the connecting head. Each station may further include structure for installing/removing a cutting nozzle, cleaning a cutting nozzle, and/or inspecting the optical system or cutting nozzle.

Abstract: Temperature compensation in the context of capacitive distance measurement with the aid of an LC oscillator The invention relates to a method for temperature compensation of an LC oscillator (8) having a machining head (4) and serving for the capacitive measurement of a distance between the machining head (4) and a workpiece (7), in which an output signal (S) of the LC oscillator (8) is transmitted to an evaluation unit (2) arranged separately from the machining head (4). The temperature (T) of the LC oscillator (8) is measured with the aid of the temperature sensor (29) and supplied to the evaluation unit (2). In the evaluation unit (2), temperature compensation of the output signal (S) of the LC oscillator (8) is effected using the measured temperature (T) and a temperature coefficient (K) which is assigned to the machining head (4) and can likewise be transmitted from the machining head (4) to the evaluation unit (2).