JJG117-78平板检定规程规定:对于一般精度的平面,从减少测量工作量考虑,允许采用“三点法”或“对角线法”进行评定。但对于高精度的平面检定或仲裁性检定,必须按“最小条件法”评定。目前普遍采用求最小值的方法是简便图解法。就是对现有任一种平面度评定方法所得到的各被测点平面度按逐次逼近原理以求得最小值δ。这种方 JJG117-78 flat test procedures provides: For the general accuracy of the plane, to reduce the measurement workload to allow the use of “three point method” or “diagonal method” to be assessed. However, for high-precision flat test or arbitration test, it must be evaluated according to the “minimum condition method”. At present, the commonly used method to find the minimum value is a simple graphical method. That is, the method of successive approximation is adopted to obtain the minimum value δ for each measured flatness obtained by any existing flatness assessment method. This side