This document specifies field procedures to be adopted when determining and evaluating the precision (repeatability) of rotating lasers, the uncertainty of measurement results obtained by geodetic instruments and their ancillary equipment, particularly when used in building and surveying measurements for levelling tasks. Primarily, these tests are intended to be field verifications of the suitability of a particular instrument for the immediate task at hand and to satisfy the requirements of other standards. They are not proposed as tests for acceptance or performance evaluations that are more comprehensive in nature.

This document can be considered as one of the first steps in the process of evaluating the uncertainty of a measurement (more specifically a measurand). The uncertainty of a result of a measurement is dependent on a number of parameters. Therefore, this document differentiates between various quality measures and testing objectives, including repeatability and reproducibility (between-day repeatability), and provides a thorough assessment of all potential error sources, as specified by ISO/IEC Guide 98-3 and ISO 17123-1.

These field procedures have been developed specifically for in situ applications without the need for special ancillary equipment and are purposefully designed to minimize atmospheric influences.