1.1本试验方法涵盖了使用圆形轨道测量仪（CTMeter）获取和分析路面宏观纹理轮廓的程序。 1.2电流互感器由电荷耦合器件（CCD）激光位移传感器组成，该传感器安装在一个旋转的臂上，使位移传感器沿着直径为284 mm（11.2 in.）的圆形轨道旋转。 1.3连续测程仪设计用于测量动态摩擦测试仪（DFTester）测量的相同圆形轨道。 1.4连续测厚仪既可用于实验室调查，也可用于现场实际铺设表面。 1.5为CTMeter开发的软件报告宏观纹理轮廓的平均轮廓深度（MPD）和均方根（RMS）值。 1.6以SI（公制）单位表示的值应视为标准值。 英寸-磅当量是合理的，而不是精确的数学转换。 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 在PIARC国际实验中( 1. 3. )结果发现，体积平均纹理深度（MTD）与国际摩擦指数的速度常数高度相关。已经发现，使用连续油管流量计的八个管段的MPD值的平均值与MTD高度相关，可以代替体积测量来确定MTD( 2. ). 通过CTMeter从MPD估算MTD的推荐关系为: 当MTD和MPD以毫米表示时， 或: 当MTD和MPD以英寸表示时。 笔记 1-这些等式不同于实践E 1845中给出的等式 ，用于根据线性轮廓估计纹理深度。 表面的MPD和均方根值的比较提供了纹理性质的信息，即纹理是正的还是负的( 3. ). 可以对各个段进行分析，以检查平行于行驶方向（段A和E）和垂直于行驶方向（段C和G）的轮廓。该信息在研究具有显著方向特征纹理的表面时特别有用。

1.1 This test method covers the procedure for obtaining and analyzing pavement macrotexture profiles using the Circular Track Meter (CTMeter). 1.2 The CTMeter consists of a charge coupled device (CCD) laser- displacement sensor which is mounted on an arm that rotates such that the displacement sensor follows a circular track having a diameter of 284 mm (11.2 in.). 1.3 The CTMeter is designed to measure the same circular track that is measured by the Dynamic Friction Tester (DFTester). 1.4 The CTMeter can be used both for laboratory investigations and in the field on actual paved surfaces. 1.5 The software developed for the CTMeter reports the Mean Profile Depth (MPD) and the Root Mean Square (RMS) values of the macrotexture profiles. 1.6 The values stated in SI (metric) units are to be regarded as standard. The inch-pound equivalents are rationalized, rather than exact mathematical conversions. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== In the PIARC International Experiment ( 1 3 ) it was found that the volumetric mean texture depth (MTD) was highly correlated to the speed constant of the International Friction Index. It has been found that the average of the MPD values for the eight segments using the CTMeter is extremely highly correlated with the MTD and can replace the volumetric measurement for determination of the MTD ( 2 ). The recommended relationship for the estimate of the MTD from the MPD by the CTMeter is: when MTD and MPD are expressed in millimetres, or: when MTD and MPD are expressed in inches. Note 1—These equations differ from those given in Practice E 1845 , which are for the estimated texture depths from linear profiles. Comparison of the MPD and the RMS for a surface provides information of the nature of the texture, that is, whether the texture is positive or negative ( 3 ). Analysis of the individual segments can be performed to examine the profile parallel to the direction of travel (segments A and E) and perpendicular to the direction of travel (segments C and G). This information could be particularly useful in the study of surfaces that have texture with significant directional characteristics.