The ASTM E898-20 standard practice provides a guiding method for calibrating non-automatic weighing instruments, designed to ensure measurement accuracy and Reliability of weighing instruments. The standard applies to a variety of non-automatic weighing instruments, such as lever scales, weight scales, etc., and focuses primarily on how weighing instruments can be checked and adjusted by using appropriate standard weights and calibrating tools. The standard defines the steps in the calibrating process, including the selection of calibrating equipment, the requirements of the calibrating environment, and how instruments of different ranges and accuracy levels can be calibrated. By following this practice, users can ensure that the accuracy of non-automatic weighing instruments meets the requirements for use, thus improving Reliability of weighing operations and accuracy of measurement results. This is especially important for weighing in industrial, commercial and laboratory environments.