GB/T 7247.4-2025Safety of laser products - Part 4: Laser guards (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document is Part 4 of GB/T 7247 "Safety of Laser Products". GB/T 7247 "Safety of Laser Products" has been published for Lower part.

--- Part 1: Equipment classification and requirements;

--- Part 2: Safety of optical fiber communication systems (OFCS);

--- Part 3: Guidelines for laser shows and performances;

--- Part 4: Laser protection screens;

--- Part 5: Producer's checklist for GB/T 7247.1;

--- Part 9: Maximum permissible exposure to incoherent optical radiation;

--- Part 13: Classification and measurement of laser products;

--- Part 14: User Guide.

This document replaces GB/T 7247.4-2016 "Safety of Laser Products Part 4: Laser Protection Screens" and GB/T 7247.4-Compared with 2016, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

--- Added some terms and definitions (see Chapter 3);

--- "Protective screen for laser processing machine" is changed to "Requirements for laser protective screen" (see Chapter 4, Chapter 4 of the 2016 edition);

--- The content of Appendix G has been changed (see Appendix G, Appendix G of the 2016 edition).

This document is equivalent to IEC 60825-4:2022 "Safety of Laser Products Part 4: Laser Protection Screens".

Introduction

Under low irradiance or irradiation, the selection of materials and thickness for shielding laser radiation mainly depends on the required shielding effect of laser radiation.

Sufficient optical attenuation. Under high irradiance or irradiation, the erosion effect of laser radiation on the protective screen material must also be considered.

Typical phenomena are melting, oxidation or ablation, which can cause the laser radiation to penetrate the originally opaque material.

GB/T 7247 "Safety of Laser Products" is intended to consist of the following parts.

--- Part 1: Equipment classification and requirements. Due to the wide range of wavelength, energy and pulse characteristics of laser beams, when using laser products, the degree of potential hazard varies greatly, and it is not possible to simply classify laser products using uniform safety limits.

Evaluate the degree of optical radiation hazards of lasers and laser products and determine control measures.

--- Part 2: Safety of optical fiber communication systems (OFCS). Based on the safety of reasonably foreseeable fault conditions [such as cable break, optical fiber the level is divided according to the degree of exposure to optical radiation in the case of loose fiber connectors, etc.

The corresponding hazard level of accessible locations is specified based on the characteristics of the accessible locations to determine the equivalent safety protection measures.

--- Part 3: Guidelines for laser shows and performances. For Class 3B and Class 4 lasers used in similar venues such as theater projections and stage performances.

For optical products, any possible occurrence during laser operation that exceeds the maximum permissible exposure that may cause biological effects and hazards to human eyes and skin.

The MPE analysis is given to clarify the responsibilities of on-site design, installation, operation and performance personnel, as well as risk control and evaluation.

Estimate to reduce risk.

--- Part 4: Laser protection screen. Aims to specify permanent and temporary (such as maintenance period) enclosures used to enclose the working area of the laser processing machine.

Laser protection screens and technical requirements for special laser protection screens to prevent personnel around the processing area from being exposed to laser radiation harm.

--- Part 5: Producer's checklist for GB/T 7247.1.Aims to provide a reference inspection procedure to ensure Verify whether the product meets the classification and requirements of GB/T 7247.1 for equipment, and enhance the enforceability and Operability.

--- Part 8: Guidelines for the safe use of lasers on the human body. Aims to guide how to incorporate the safe use of lasers into medical laser practice.

Practice, establish safety procedures, preventive measures and user control measures, strengthen the establishment of a system for all personnel involved in the use of lasers the necessity of safety framework system and training.

--- Part 9: Maximum permissible exposure to incoherent optical radiation. This is intended to provide the maximum permissible exposure to the human eye from artificial light sources with a wavelength of 180nm to 3000nm.

When the skin is exposed to light, the maximum permissible exposure (MPE) limit of the light radiation is controlled.

--- Part 12: Safety of free-space optical communication systems for information transmission. Aims to give the wavelength range of 180nm~1mm Guidelines for the manufacture and safe use of laser products and systems for point-to-point or point-to-multipoint free-space optical data transmission to protect people from potentially hazardous optical radiation generated by free-space optical communication systems.

--- Part 13: Classification measurement of laser products. Aims to give the emission level of laser output energy according to GB/T 7247.1 Measurement and analysis methods give guidance on the classification of laser products.

--- Part 14: User Guide. It puts forward requirements for users to use laser products exceeding Class 1 and Class 2, aiming to help users Product users and their manufacturers understand the general principles of safety management, identify possible hazards, assess the severity of potential hazards, establish and Provide appropriate control measures.

--- Part 17: Safety of passive optical components and cables used in high optical power optical fiber communication systems.

For high optical powers above Class 3B in operation, safety precautions for thermal effects, optomechanical effects and related effects are given.

To prevent and protect other safety issues that may be caused to connectors, etc.

--- Part 18: Transmission system guide. Aims to specify the layout, installation and use requirements of light guide systems, including free space laser Transmission and fiber optic transmission, protective measures implemented to protect personnel from laser radiation hazards, and risk assessment methods.

--- Part 19: Mobile platform laser products. This is intended to provide laser products mounted on mobile platforms based on the movement of the platform.

The velocity-dependent closest achievable position (VCPHA) is used to assess laser hazards to avoid over-reaching while ensuring safety.

The laser hazard is rigorously evaluated and precautions for applying this condition are given.

--- Part 20: Laser radiation safety requirements for products intended to expose the eyes or face. Intended to consider direct exposure to the face or eye area Possible failure of consumer Class 1 laser products (such as facial or retina/iris recognition, AR/VR/MR glasses/headsets, etc.) the FMEA method focuses on safety and provides requirements based on risk analysis to reduce the risk of product failure.

Failure may occur at any time during the service life, causing potential damage to the eyes and face.

--- Part 21: Automatic emission control (AEC). Aims to address the issues that manufacturers may encounter when incorporating automatic emission control (AEC) into their laser products.

products, so as to reduce the hazards of light radiation and produce better performance products under unprotected conditions.

Provide better understanding of the performance requirements of AECs and the methods that can be used to determine hazard classifications and verify that they are operating as intended.

guide.

Safety of Laser Products Part 4: Laser protection screens

1 Scope

This document specifies the requirements and specifications for permanent and temporary (e.g. during maintenance) laser protection screens used to enclose the working area of laser processing machines.

Technical requirements for special laser protection screens.

This document applies to all components of laser protection screens, including transparent (visible transmission) screens and viewing windows, baffles, laser protection curtains, and protective walls.

This document also defines.

a) How to evaluate and standardize the protective performance of laser shields; and

b) How to choose laser protection screen.

Note. Requirements for optical path components, beam terminators and other parts of protective covers that are not enclosed in the processing area of laser products are included in IEC 60825-1 in.

Appendix A of this document gives general guidance on the design and selection of laser shields, and Appendix B gives the expected exposure limit (FEL).

Appendix C provides a detailed explanation of the definition of terms, Appendix D specifies the detection of special laser protection screens, and Appendix E provides the laser protection screen

Annex F provides guidance on the suitability assessment of laser shields, and Annex G specifies the light transmission system.

This document only covers the protection against laser radiation and does not cover the secondary radiation hazards that may arise during material processing.

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to this document.

GB/T 7247.1-2024 Safety of laser products Part 1: Equipment classification and requirements (IEC 60825-1:2014, IDT) ISO 11553-1 Safety of machinery - Laser process - Laser safety requirements for laser processing machines ingmachines-Part 1: Lasersafetyrequirements) Note. GB/T 18490.1-2017 Mechanical safety Laser processing machines Part 1: General safety requirements (ISO 11553-1:2005, MOD) ISO 12100 Safety of machinery - General principles for risk assessment and risk reduction principlesfordesign-Riskassessmentandriskreduction) Note. GB/T 15706-2012 General principles for safety design of machinery - Risk assessment and risk reduction (ISO 12100:2010, IDT) ISO 13849-1 Safety of machinery - Safety-related parts of control systems - Part 1: General principles for design Safety-relatedpartsofcontrolsystems-Part 1: Generalprinciplesfordesign) Note. GB/T 16855.1-2018 Safety of machinery - Safety-related components of control systems - Part 1: General principles for design (ISO 13849-1:2015, IDT) IEC 60825-1 Safety of laser products - Part 1: Equipment classification and requirements Equipmentclassificationandrequirements) IEC 61508 (all parts) Functional safety of electrical/electronic/programmable electronic safety-related systems electrical/electronic/programmableelectronicsafety-relatedsystems) Note. GB/T 20438 (all parts) Functional safety of electrical/electronic/programmable electronic safety-related systems [IEC 61508 (all parts)]