摘  要：大长度测量仪检定工作一般在野外基线场上进行，耗时费力、强度高效率低、受环境影响严重等问题一直困扰计量检定人员。为改变这一落后作业模式，在手持激光测距仪室内检定装置研制成功的基础上，该文提出基于折光腔法与虚拟基线理论构造鉴相式大长度测量仪检定装置，拟将野外检定基线场完整搬入室内。利用费马原理设计的折光腔将长度＞1 000 m的光路压缩在数十米以内，利用光的反射定律推导出虚拟基线（室内大长度各段标准值）的计算方法，同时进一步提出检定装置的结构设计，技术参数及控制措施，并通过对系统潜在影响因素分析以论证该大长度室内检定装置的可行性。

关键词：大长度；折光腔；虚拟基线；费马原理

文献标志码：A       文章编号：1674-5124（2015）12-0021-04

Verification method of phase detector large length measuring instrument

based on refraction cavity

HUANG Su， PAN Jiasheng， ZHANG Yong

（1. Guangdong Provincial Key Laboratory of Modern Geometric and Mechanical Metrology Technology，

Guangzhou 510405，China；

2. Guangdong Institute of Metrology，Guangzhou 510405，China）

Abstract: Generally， the calibration work is carried out in outdoor fields through large length meters， but it is time-consuming， inefficient and severely affected by the surroundings， which have been long plaguing the metrological verification personnel. based on the indoor test device for portable laser rangefinder， this paper has proposed to design a calibration device for phase-demodulation large-length measuring instrument according to refraction cavity and virtual baseline theory， that is， to move verification baseline fields from outdoor to indoor. The refraction cavity designed by Fermat’s principle is used to fold the light path greater than 1 000 m within 10 m and at the same the reflection law of light is applied to deduce a calculation formula to calculate the virtual baseline （standard value at each section of indoor large length）. The structure design， technical parameters and control measures of the calibrating device has been discussed as well， and its feasibility has been demonstrated by analyzing the potential influence factors of the system.

Keywords: long length； refraction cavity； virtual baseline； Fermat’s principle