针对国内有钢厂使用欧洲标准DINEN10049-2006采用2．5mm的长波滤波器的截止波长进行冷轧金属薄板表面粗糙度Ra的测试参数设置，与GB／T2523～2008表面波纹度Wa测试“用于抑制短波部分的波长一般为0．8mm”和“用于抑制长波部分的波长一般为8mm”发生重叠的问题，从Ra和Wa的定义解读入手，系统地开展了麻面薄板Ra和Wa测试技术研究；通过诠释实现测试任务的滤波器的传输带原理，分析了对于Ra小于2μm的薄板进行Ra测试，其长波与短波滤波器之间的传输带不是越宽测试精度就越高的原因；同时提出并验证了以与ISO4288-1996匹配的0．8mm的截止波长为基础，将取样区间数由5个增加到16个，使评定长度由4mm加长到12．8mm，作为沟通与DINEN10049-2006中12．5mm的评定长度保持基本一致的新的系统解决方案。

On the issue of overlappnig problem of European standard DIN EN 10049—2006 adopting 2.5 mm long wave tliter cut-off wavelength to measure the surface roughness Ra of cold rolled steel sheets and GB/T 2523-2008 adopting 0.8 mm short wave tiiter cut-off wavrlength and 8 mm long wave tiiter cut-off wavrlength to measure the surface waynness Wa， systematic measurement of Ra and Wa of stochastic surface cold rolted steel sheets was done staring from the nrterpretation of Ra and Wa.The reason of that the measurement accuracy didn't nncreased with the mcrease of the transmission band wddth between the short wave and the long wave for the steel sheets with Ra< 2 μαη，was analyzed by niterpreting the principte of the filter transmission band which completing the measurement. The method of increasing samping rnterval numbers from 5 to 16 to make the evaluation tength nncrease from 4 mm to 12.8 mm was raised and vetitied on the basis of 0.8 mm cut-off wavrlength of ISO 4288-1996，as a solvrng method to coinaide to the 12.5 mm evaluation tength of DIN EN 10049-2006.