GB/T 24631.2-2009 focuses on standardized operation for straightness in product geometric technical specifications. The standard details the standardized operation process for straightness measurement and evaluation, covering specific methods for using different measurement tools, such as how to correctly place instruments, plan measurement routes, and data collection and processing steps. By clarifying these operations, it provides a unified standard for accurate measurement of straightness, ensuring the accuracy and comparability of straightness measurement results in different measurement scenarios, and helping industrial production to accurately control the straightness of parts.