竖盘指标差及2C值(两倍的视准轴误差)是影响全站仪角度测量精度的两个重要因素.利用平行光管检验校正台分别对一台竖盘指标差超标的南方测绘NTS-312L型全站仪和一台2C超标的南方测绘NTS-312L型全站仪进行了校正.校正后,前者的竖盘指标差从24″减小至6″,后者的2C从19″减小至–6″,校正结果符合《全站型电子速测仪检定规程JJG100-2003》.为了对校正结果进行进一步检核,分别对两台全站仪进行了外业测试,结果显示,前者的竖盘指标差在–3″到6″范围内,后者的2C值在–6″到5″范围内,与实验结果基本符合.
Index error of vertical circle and2C value(two times of collimation axis error)are two important indicators which affect the precision of total station's angle measurement.A South NTS-312L total station with index error of vertical circle overrun and a South NTS-312L total station with2C overrun are corrected by the calibrator stand with collimators.The experiments show that the index error of vertical circle of the former is reduced from24″to6″and2C of the latter from19″to-6″respectively after calibrating,the calibrating results according with Verification Regulation of Electronic Tachometer Total Station JJG100-2003.In order to check the calibration results further,both total stations are tested in a field survey,and the results show that the vertical index of the former changes between-3″to6″range,and2C value of the latter varies in-6″to5″range,these numbers basically in agreement with the calibration experiment.