A wind turbine blade extending along a longitudinal axis from a root end to a tip end and in a transverse plane perpendicular to the longitudinal axis, the transverse plane having a main axis extending through an elastic center point, wherein the wind turbine blade comprises a sensor system including a first sensor set for measuring a first bending moment in a first sensor position at a first distance from the root end, the first sensor set comprising a first primary sensor for measuring a primary component and a first secondary sensor for measuring a secondary component, wherein a first primary sensor axis in the transverse plane is oriented in a direction defined by the first primary sensor and the elastic center point, and a first secondary sensor axis in the transverse plane is oriented in a direction defined by the first secondary sensor and the elastic center point, and wherein an angle between the first primary sensor axis and the first secondary sensor axis is in the range from 50° to 130°