Optics and optical instruments. Reference wavelengths shop-only will maintain their circuit integrity

will maintain their circuit integrity for life safety and fire-fighting

International concern over damage to the environment (e

Protection against indirect contact in TN-systems

BS 4142 is used to assess the impact of industrial and commercial sound

Editorial change to harmonize the text with other standards in this series

Optics and optical instruments. Reference wavelengths shop-only will maintain their circuit integrity1 Scope This International Standard specifies two reference wavelengths to be used for the characterization of optical materials, optical systems and instruments, as well as ophthalmic lenses. It defines the associated principal refractive indices and principal dispersions, as well as the Abbe numbers with regard to these reference wavelengths and principal dispersions.