DIN ISO 17123-4:2017-09

This part of ISO 17123 specifies field procedures to be adopted when determining and evaluating the precision (repeatability) of electro-optical distance meters (EDM instruments) and their ancillary equipment when used in building and surveying measurements. This part of ISO 17123 is applicable to reflector-type EDM instruments only and is not designed to determine the precision of non-prism EDM types. 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. This part of ISO 17123 can be thought of 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 we differentiate between different measures of accuracy and objectives in testing, like repeatability, reproducibility (for example between day repeatability), and of course a thorough assessment of all possible error sources, as prescribed by ISO/IEC Guide 98-3 and by ISO 17123-1. ISO 17123-1 has been prepared by Technical Committee ISO/TC 172 "Optics and photonics", Subcommittee 6 "Geodetic instruments and surveying instruments", the secretariat of which is held by SNV (Switzerland). Working Committee NA 005-03-04 AA "Geodätische Instrumente und Geräte" ("Geodetic instruments and devices") at DIN Standards Committee Building and Civil Engineering (NABau) is responsible for this standard.