The dimensional metrology group at the National Institute of Standards and Technology (NIST) has developed an ultra-high accuracy laser micrometer capable of external diameter measurements with a targeted expanded uncertainty, U(k = 2), of less than 20nm. This instrument is an advanced iteration of a design developed at NIST in the 1990s and has been continuously improved since its inception. This newest approach takes advantage of the lessons learned through two decades of operation, process control measurement data, and performance analysis. This approach advances the state of the art for diameter measurements within an artifact diameter range of 0.02mm to 55mm. The instrument makes use of low thermal expansion materials, a stable structural design, environmental control, and remote manipulation of the artifacts to address the most significant uncertainty sources identified in previous versions of the instrument. A review of the instrument development and components will be presented. We will outline the significant contributions to the operational measurement uncertainty budget for this instrument along with identifying the high accuracy applications that will benefit from this effort.

美国国家标准技术研究院（NIST）的尺寸计量小组开发了一种超高精度激光测微仪，该测微仪能够以目标扩展不确定度U（k= 2），小于20nm。该仪器是1990年代NIST开发的一种设计的高级迭代，自诞生以来就不断得到改进。最新的方法利用了通过二十年的操作，过程控制测量数据和性能分析所获得的经验教训。这种方法提高了在0.02mm至55mm伪影直径范围内进行直径测量的最新技术水平。该仪器利用低热膨胀材料，稳定的结构设计，环境控制和工件的远程操作来解决仪器先前版本中确定的最重要的不确定性来源。将介绍仪器开发和组件的评论。