在X射线应力测定中,sin~2Ψ法的测量精确度和准确度比0～45°法及45°单倾法高,而且可根据2θ-sin~2Ψ关系的直线性检查测量结果的准确程度,因而得到广泛的应用。用sin~2Ψ法计算应力时,先要根据最小二乘法原理求出2θ-sin~2Ψ回归直线的斜率M: M=α2θ/αsin~2Ψ In the X-ray stress measurement, the measurement accuracy and accuracy of the sin ~ 2Ψ method are higher than those of the 0 ~ 45 ° method and the 45 ° single-dip method, and the accuracy of the measurement results can be checked according to the linearity of the 2θ-sin ~ 2Ψ relationship , Which has been widely used. Calculate the stress with sin ~ 2Ψ method, we must first get the slope M of 2θ-sin ~ 2Ψ regression line according to the principle of least squares: M = α2θ / αsin ~ 2Ψ