Compensation Motion and Calibration for Scale Calibration Machine

The National Institute of Metrology Thailand (NIMT) has developed a self-built scale calibration machine to verify the accuracy of rulers and tape measures, supporting and promoting domestic industries following ISO/IEC 17025 and ISO 10012 [1–2]. The design of the machine is based on the Japanese Industrial Standards JIS B 7516 standard [3], which specifies calibration procedures for metal rules. A key challenge in controlling the one-dimensional motion of the machine lies in addressing the 6 degrees of freedom (6-DoF) [4–6], which can affect accuracy and precision. The scale calibration machine consists of several components, including a beam, ball screw, motor drive, driver motor, digital camera, and controller. To ensure precise motion control, it is essential to compensate for errors caused by mechanical and environmental factors and integrate these compensation methods into the control software. This approach not only guarantees accurate and reliable calibration results but also enhances the machine's performance in maintaining consistent motion. Through this development, NIMT aims to strengthen its metrological capabilities, support the growth of local industries, and further establish itself as a leader in the field of metrology.