Yandayan T, Geckeler R D, Aksulu M, Akgoz S A, Ozgur B
TUBITAK Ulusal Metroloji Enstitüsü, Dr.Zeki Acar Cad. No:1, 41470 Gebze-Kocaeli, Turkey.
Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
Rev Sci Instrum. 2016 May;87(5):051903. doi: 10.1063/1.4950720.
The application of advanced error-separating shearing techniques to the precise calibration of autocollimators with Small Angle Generators (SAGs) was carried out for the first time. The experimental realization was achieved using the High Precision Small Angle Generator (HPSAG) of TUBITAK UME under classical dimensional metrology laboratory environmental conditions. The standard uncertainty value of 5 mas (24.2 nrad) reached by classical calibration method was improved to the level of 1.38 mas (6.7 nrad). Shearing techniques, which offer a unique opportunity to separate the errors of devices without recourse to any external standard, were first adapted by Physikalisch-Technische Bundesanstalt (PTB) to the calibration of autocollimators with angle encoders. It has been demonstrated experimentally in a clean room environment using the primary angle standard of PTB (WMT 220). The application of the technique to a different type of angle measurement system extends the range of the shearing technique further and reveals other advantages. For example, the angular scales of the SAGs are based on linear measurement systems (e.g., capacitive nanosensors for the HPSAG). Therefore, SAGs show different systematic errors when compared to angle encoders. In addition to the error-separation of HPSAG and the autocollimator, detailed investigations on error sources were carried out. Apart from determination of the systematic errors of the capacitive sensor used in the HPSAG, it was also demonstrated that the shearing method enables the unique opportunity to characterize other error sources such as errors due to temperature drift in long term measurements. This proves that the shearing technique is a very powerful method for investigating angle measuring systems, for their improvement, and for specifying precautions to be taken during the measurements.
先进的误差分离剪切技术首次应用于使用小角度发生器（SAG）对自准直仪进行精确校准。实验是在图比塔克斯计量研究所（TUBITAK UME）的高精度小角度发生器（HPSAG）上，在经典尺寸计量实验室环境条件下实现的。经典校准方法达到的5毫弧度秒（24.2纳弧度）的标准不确定度值提高到了1.38毫弧度秒（6.7纳弧度）的水平。剪切技术为在不借助任何外部标准的情况下分离设备误差提供了独特机会，德国物理技术研究院（PTB）首先将其应用于使用角度编码器对自准直仪的校准。在洁净室环境中使用PTB的主角度标准（WMT 220）进行了实验验证。该技术在不同类型角度测量系统中的应用进一步扩展了剪切技术的范围，并揭示了其他优势。例如，SAG的角刻度基于线性测量系统（例如，HPSAG的电容式纳米传感器）。因此，与角度编码器相比，SAG表现出不同的系统误差。除了对HPSAG和自准直仪进行误差分离外，还对误差源进行了详细研究。除了确定HPSAG中使用的电容式传感器的系统误差外，还证明了剪切方法为表征其他误差源提供了独特机会，例如长期测量中由于温度漂移引起的误差。这证明了剪切技术是一种非常强大的方法，可用于研究角度测量系统、改进角度测量系统以及确定测量过程中应采取的预防措施。
