双斜面楔块
wedge block with two inclined planes
上楔块顶面
Top Surface of Upper Wedge
阶梯-楔块校准片
Step-wedge calibration film
阶梯楔块校准底片
Step- wadge calibration film
阶梯-楔块比较片
Step-wedge comparison film
阶梯楔块比较底片
Step- wadge comparison film
对数曲面楔块
logarithm curved surface sprag