Ophthalmic optics. Visual acuity testing. Standard and clinical optotypes and their presentation1 Scope This document specifies a range of Landolt ring optotypes and describes a method for measuring distance visual acuity under photopic conditions for the purposes of certification or licensing. This document is neither intended as a standard for clinical measurements nor for the certification of blindness or partial sight. Other optotypes used for clinical investigations are described in Annex A for information.

These requirements are supplementary to those stated in EN ISO 3691‑1:2015

BS 2589 outlines the material and dimensions of the types of railway track spanner known by the following names:

4 Drop test method

Annex A (normative) Ruling sections for the mechanical properties

Adaptation of the competence requirements to reflect the greater focus in ISO 14001:2015 on expected outcomes

BS EN 60523 is an international standard that discusses the uses of direct-current potentiometers

BS 1083 covers precision hexagon bolts

BS EN 4626-003 on rectangular optical multi-contact connector adaptor for the plug is useful for:

NOTE It is necessary for a pipe or fitting used for water supply which is exposed to visible light during service to be sufficiently opaque to prevent algae growth

BS EN 62021-3 is beneficial as it could result in improved characteristics such as optimized liquid cost

This can help to assess the effectiveness of your new candidate coating systems in inhibiting microbial (fungal) growth

including so-called losers and gainers