A method for operating an air jet spinning machine having at least one spinning unit with one spinning nozzle for producing a yarn is provided. During the operation of the spinning unit, the spinning nozzle feeds a fiber composite through an inlet in a predefined transport direction. The fiber composite within a vortex chamber of the spinning nozzle receives a twist with the assistance of a vortex air flow, such that a yarn is formed from the fiber composite. With the assistance of at least one sensor system, the yarn leaving the outlet is monitored with regard to defined yarn flaws. The production of yarn is interrupted upon the detection of a corresponding yarn flaw. Between the detection of the specified yarn flaw and the interruption of the yarn production, a cleaning process is carried out during which an additive is fed to the spinning unit and is applied to the fiber composite and/or the yarn produced from the fiber composite and/or on parts of the spinning nozzle.

A method is provided to operate an air jet spinning machine, having at least one spinning unit with a spinning nozzle for manufacturing yarn, in which a fiber strand is fed to the spinning nozzle through an inlet and is imparted a twist inside a vortex chamber of the spinning nozzle by means of a swirled air current so that a yarn is formed from the fiber strand. An additive is added with an additive dispenser to the spinning unit while the air jet spinning machine is operating and applied on the fiber strand or on sections of the spinning nozzle and/or the yarn. At least one physical parameter of the yarn is monitored by a sensor system wherein, based on a measured value supplied by the sensor system correlated with the parameter, it is determined whether and/or how much additive was applied.

A method is provided to operate an air jet spinning machine, having at least one spinning unit with a spinning nozzle for manufacturing yarn, in which a fiber strand is fed to the spinning nozzle through an inlet and is imparted a twist inside a vortex chamber of the spinning nozzle by means of a swirled air current so that a yarn is formed from the fiber strand. An additive is added with an additive dispenser to the spinning unit while the air jet spinning machine is operating and applied on the fiber strand or on sections of the spinning nozzle and/or the yarn. At least one physical parameter of the yarn is monitored by a sensor system wherein, based on a measured value supplied by the sensor system correlated with the parameter, it is determined whether and/or how much additive was applied.

A method of adjustment of a workstation and a yarn clearer (yarn quality sensor (9)) at a workstation of a textile machine, in which measurement and/or calculation creates a reference value (P.sub.R) of a particular parameter of yarn (1), to which the current value (P.sub.P) of the particular parameter measured is compared during the continuous production of yarn. The reference value of the particular yarn parameter is determined as the reference value of (P.sub.fR) of the particular yarn parameter of deliberately defective yarn (1) intentionally produced at the particular workstation and subsequently it is compared to the current and/or reference value (P.sub.P, P.sub.0, P.sub.PR, P.sub.0R) of the particular parameter of yarn (1) produced at the particular workstation with production quality or higher than production quality.