NOTE 1 Because of the rapid rate of development of sensor and control equipment, this document is intended as an overview and uses examples and general requirements, not detailed equipment specifications. Detailed information additional to that contained in this document can be obtained by referring to the Bibliography.

NOTE 2 Although EC directives become matters of law in member states of the EU and some other situations, this standard is intended for wider use and hence those directives with clear technical guidance of a type that would generally be appropriate in a standard are referenced in the text and listed in the Bibliography. The alternative of listing requirements copied from directives would potentially create unacceptable conflict when directives are revised.