This chapter delves into the metrological support of information-measuring systems (IMSs), emphasizing the need for updated requirements to describe the properties of measuring instruments and integrate computing components within the system architecture. It outlines the tasks and activities essential for ensuring accurate metrological characteristics throughout the IMS life cycle, including error analysis, evaluation of technical solutions, and certification processes. The study categorizes methods for determining metrological characteristics into groups, with each method’s specific requirements highlighted, and presents an approach for calculating the systematic and random error components, permissible errors, and standard deviations. By discussing both theoretical and experimental techniques, the chapter provides a comprehensive methodology for calculating error limits, evaluating measurement channel accuracy, and ensuring compliance with regulatory standards. The importance of metrological certification for computer programs and the need for standardized procedures in sectors like healthcare, manufacturing, and environmental protection are also emphasized. Through detailed analysis and proposed methodologies, the chapter aims to enhance the reliability and accuracy of IMSs.