When measuring system is calibrated, different standardrod gets different calibration coefficient.
在系统标定时，不同标准件的标定系数不一致。
2
In dynamic measuring process, the same standardrod gets different measuring outcome in different place within measuring range.
动态测量时，同一个标准件在测量范围内的不同位置测量结果不同。
3
As a scale cover on the water regulating valve cover is marked with scales, by matching with a standardrod, the regulated position of the water regulating valve cover at each time can be known.