IEC 61496-2:2020 pdf download

IEC 61496-2:2020 pdf download.Safety of machinery – Electro-sensitive protective equipment
1 Scope
This clause of Part 1 is replaced by the following: This part of IEC 61496 specifies requirements for the design, construction and testing of electro-sensitive protective equipment (ESPE) designed specifically to detect persons as part of a safety-related system, employing active opto-electronic protective devices (AOPDs) for the sensing function. Special attention is directed to features which ensure that an appropriate safety-related performance is achieved. An ESPE can include optional safety- related functions, the requirements for which are given in Annex A of IEC 61496-1:2020 and of this document. This document does 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. Excluded from this document are AOPDs employing radiation at wavelengths outside the range 400 nm to 1 500 nm. This document can be relevant to applications other than those for the protection of persons, for example, the protection of machinery or products from mechanical damage. In those applications, additional requirements can be necessary, for example, when the materials that are to be recognized by the sensing function have different properties from those of persons. This document does not deal with electromagnetic compatibility (EMC) emission requirements.
3 Terms and definitions
This clause of Part 1 is applicable except as follows: Addition: 3.201 active opto-electronic protective device AOPD device whose sensing function is performed by opto-electronic emitting and receiving elements detecting the interruption of optical radiations generated, within the device, by an opaque object present in the specified detection zone (or for a light beam device, on the axis of the light beam) Note 1 to entry: This note applies to the French language only. 3.202 beam centre-line optical path joining the optical centre of an emitting element to the optical centre of the corresponding receiving element that is intended to respond to light from that emitting element during normal operation Note 1 to entry: The optical axis of a light beam is not always on the beam centre-line. Note 2 to entry: Physical displacement of the beam centre-line may occur as a consequence of normal operation (for example, by the use of a motor-driven mirror). Note 3 to entry: For an AOPD that operates on a retro-reflective technique, the optical path is defined by the retro-reflector target together with the emitting and receiving elements. 3.203 effective aperture angle EAA maximum angle of deviation from the optical alignment of the emitting element(s) and the receiving element(s) within which the AOPD continues in normal operation 3.204 light beam device AOPD comprising one or more emitting element(s) and corresponding receiving element(s), where a detection zone is not specified by the supplier 3.205 light curtain AOPD comprising an integrated assembly of one or more emitting element(s) and one or more receiving element(s) forming a detection zone with a detection capability specified by the supplier Note 1 to entry: A light curtain with a large detection capability is sometimes referred to as a light grid. 3.206 test piece opaque cylindrical element used to verify the detection capability of the AOPD 3.207 geometrically restricted optical design GROD AOPD using an optic design where – the effective aperture angle (EAA) of each emitting and each receiving element does not exceed the values given in Figure 6 and – the axes of the optical beams are parallel and – the spacing between beam centre-lines is uniform and – the value of detection capability is based on the complete obscuration of at least one beam for any and all positions of the test piece within the detection zone (see Figure 7). Replacement: 3.3 detection capability dimension representing the diameter of the test piece which: – for a light curtain, will actuate the sensing device when placed in the detection zone; – for a single light beam device, will actuate the sensing device when placed in the beam centre-line; – for a multiple light beam device, will actuate the sensing device when placed in any beam centre-line Note 1 to entry: The term “detection capability” can also be used to mean the ability to detect a test piece of the specified diameter.