三等金属线纹尺主要用于检定水准标尺、钢直尺以及准确度较低的线纹尺。目前,使用中的线纹尺多由黄铜、锌白铜、不锈钢等材料制成。在传统检定中,多采用与二等金属线纹尺进行比较的测量方法。随着科技的发展,激光越来越多地被应用在线纹尺的检定中。根据标准器选取和测量方式的不同,线纹尺的检定方法可分为两种形式:以激光干 Third-class metal line ruler is mainly used to test the standard ruler, steel ruler and lower accuracy ruler. At present, the use of the line ruler and more brass, zinc copper, stainless steel and other materials. In the traditional test, the use of second-class metal wire ruler compared to the measurement method. With the development of science and technology, laser is more and more used in the verification of the ruler. According to the standard selection and measurement methods, the line ruler test method can be divided into two forms: the laser dry