Patent ID: 7723930

Claim:
A method for compensating an error in the tension measurement of a continuous material web in connection with a motor drive-operated tension measuring roll, whereby the method comprises a step for determining tension T meas of the material web with a force sensor positioned to the tension measuring roll, wherein the method comprises the steps of defining frictional couple T μ and moment of inertia J of the tension measuring roll before a run-time tension measurement, defining run-time torque T mot generated by the drive motor of the tension measuring roll, defining torque T wm directed by the tension measuring roll to the material web by subtracting frictional couple T μ and moment of inertia J from defined drive motor-generated torque T mot , defining force F T directed to the material web from torque T wm directed by the tension measuring roll to the material web, defining measuring-direction force component F Tm of the measuring sensor directed by the measuring roll to the material web from force F T directed to the material web, and subtracting from the tension F meas defined with the force sensor measuring-dimension force component F Tm of the measuring sensor directed to the material web by the measuring roll to obtain a corrected measuring signal.