This part of IEC 61207 applies to the three main methods outlined in the introduction. It considers essential ancillary units and applies to analyzers installed indoors and outdoors. NOTE Safety critical applications can require an additional requirement of system and analyzer specifications not covered in this standard. This standard is intended to specify terminology and definitions related to the functional performance of para magnetic gas analyzers for the measurement of oxygen in a source gas; to unify methods used in making and verifying statements on the functional performance of such analyzers; to specify what tests should be performed to determine the functional performance and how such tests should be carried out; to provide basic documents to support the application of standards of quality assurance (ISO 9001).