Specification for red and green filters used in ophthalmic dichromatic and dissociation tests Ingestion-build-50790 BS EN 50121‑3‑1:2017+A1:2019 supersedes EN

BS EN 50121‑3‑1:2017+A1:2019 supersedes EN 50121-3-1:2015

Manufacturers of belt drives and pulleys

nor from a significant hazard to life

BS EN ISO 15351 is an International Standard which specifies a thermal conductimetric method after fusion under inert gas for the determination of nitrogen in steel and iron

BS ISO 4254-9 does not apply to:

Specification for red and green filters used in ophthalmic dichromatic and dissociation tests Ingestion-build-50790 BS EN 50121‑3‑1:2017+A1:2019 supersedes EN1 Scope This British Standard specifies requirements for red and green filters of glass or plastics materials used in ophthalmic tests as follows: a) dichromatic tests for ametropia, and b) dissociating the eyes in various tests of binocular co operation.