为降低新干线总噪声值，控制轨面粗糙度引起的轮轨间噪声，研制了轨面测量仪，并以２０ｃｍ弦长的正矢粗糙度为指标。为确保轨面良好状态：试验评价指标值应＜２０μｍ；石碴轨道上测得的噪声应＜１０５ｄＢ（Ａ）；平板轨道上应＜１０８ｄＢ（Ａ）；轨面磨削间隔周期应不超过一年 In order to reduce the total noise value of the Shinkansen and to control the noise between the wheels and rails caused by the roughness of the rail surface, a rail surface measuring instrument was developed and an index of roughness of 20 cm chord length was taken as an indicator. In order to ensure the good condition of the rail surface, the test evaluation index should be <20μm; the noise measured on the ballast track should be <105dB (A); the slab track should be <108dB (A); the track surface grinding interval should not exceed one year