Safety of machinery - Electro-sensitive protective equipment - Part 3: Particular requirements for active opto-electronic protective devices responsive to diffuse Reflection (AOPDDR)
IEC 61496-3:2018 specifies additional requirements for the design, construction and testing of electro-sensitive protective equipment (ESPE) designed specifically to detect persons or parts of persons as part of a safety-related system, employing active opto-electronic protective devices responsive to diffuse reflection (AOPDDRs) for the sensing function. Special attention is directed to requirements which ensure that an appropriate safety-related performance is achieved. An ESPE can include optional safety-related functions, the requirements for which are given both in Annex A of this document and in Annex A of IEC 61496-1:2012. IEC 61496-3:2018 not specify the dimensions or configurations of the detection zone and its disposition in relation to hazardous parts for any particular application, nor what constitutes a hazardous state of any machine. It is restricted to the functioning of the ESPE and how it interfaces with the machine. AOPDDRs are devices that have either
– one or more detection zone(s) specified in two dimensions (AOPDDR-2D), or
– one or more detection zone(s) specified in three dimensions (AOPDDR-3D)
wherein radiation in the near infrared range is emitted by an emitting element(s). When the emitted radiation impinges on an object (for example, a person or part of a person), a portion of the emitted radiation is reflected to a receiving element(s) by diffuse reflection. This reflection is used to determine the position of the object. Opto-electronic devices that perform only a single one-dimensional spot-like distance measurement, for example, optical proximity switches, are not covered by this document. IEC 61496-3:2018 does not address those aspects required for complex classification or differentiation of the object detected. IEC 61496-3:2018 does not address requirements and tests for outdoor application. Excluded from IEC 61496-3:2018 are AOPDDRs employing radiation with the peak of wavelength outside the range 820 nm to 950 nm, and those employing radiation other than that generated by the AOPDDR itself. For sensing devices that employ radiation of wavelengths outside this range, this document can be used as a guide. IEC 61496-3:2018 is relevant for AOPDDRs having a minimum detectable object size in the range from 30 mm to 200 mm. IEC 61496-3:2018 can be relevant to applications other than those for the protection of persons, for example, for the protection of machinery or products from mechanical damage. In those applications, different requirements can be appropiate, for example when the materials that have to be recognized by the sensing function have different properties from those of persons and their clothing. IEC 61496-3:2018 does not deal with electromagnetic compatibility (EMC) emission requirements. IEC 61496-3:2018 cancels and replaces the second edition published in 2008. This edition constitutes a technical revision. IEC 61496-3:2018 includes the following significant technical changes with respect to the previous edition:
a) extension of the scope from AOPDDR-2D to AOPDDR-3D;
b) extension of the scope from Type 3 ESPE to Type 2 ESPE;
c) implementation of requirements and test procedures for AOPDDR-3D and Type 2 ESPE;
d) listing of reference boundary monitoring as an optional function of the ESPE;
e) implementation of instructions for positioning of AOPDDR-3D in respect of parts of the human body;
f) revised requirement for combinations of single faults with conditions for no failure to danger, see for example 22.214.171.124, last paragraph.
IEC 61496-3:2018 is to be used in conjunction with IEC 61496-1:2012.