Relates to definitions, test methods, and procedures for systems designed for either continuous or discrete measurements and checks of thickness, mass per unit area, or mass per unit length on industrial processes. The measured process material may be in such forms as heets, coatings, laminates, tubes, or rods. This standard applies to systems with one or more outputs for display or control purposes. The measurement may also include multiple input signals with various means of compensation and signal conditioning prior to the output signals. Safety aspects are covered in other IEC and ISO standards, e.g. ISO 2919 and IEC 405. The objective of this standard is to identify the common parameters and variables and to specify standard tests and documentation which will facilitate direct comparison of the performance*characteristics of the different measurement systems. These tests are applicable to systems with either fixed or traversing measuring heads and with transmission, backscatter, or X-ray fluorescence sensors.