IEC 60079-28:2015 is available as \/2 which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition. IEC 60079-28:2015 specifies the requirements, testing and marking of equipment emitting optical radiation intended for use in explosive atmospheres. It also covers equipment located outside the explosive atmosphere or protected by a Type of Protection listed in IEC 60079-0, but which generates optical radiation that is intended to enter an explosive atmosphere. It covers Groups I, II and III, and EPLs Ga, Gb, Gc, Da, Db, Dc, Ma and Mb. This standard does not cover ignition by ultraviolet radiation and by absorption of the radiation in the explosive mixture itself. Explosive absorbers or absorbers that contain their own oxidizer as well as catalytic absorbers are also outside the scope of this standard. This second edition cancels and replaces the first edition, published in 2006, and constitutes a technical revision. Refer to the Foreword of the document for a complete listing of the technical changes between edition 2.0 and previous edition of the document. Keywords: equipment emitting optical radiation intended for use in explosive atmospheres<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 67<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 74<\/td>\n | 1 Scope <\/td>\n<\/tr>\n | ||||||
| 75<\/td>\n | 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 78<\/td>\n | 4 General requirements 5 Types of protection 5.1 General Tables Table 1 \u2013 EPLs achieved by application of types of protection for optical systems <\/td>\n<\/tr>\n | ||||||
| 79<\/td>\n | 5.2 Requirements for inherently safe optical radiation \u201cop is\u201d 5.2.1 General 5.2.2 Continuous wave radiation <\/td>\n<\/tr>\n | ||||||
| 80<\/td>\n | Table 2 \u2013 Safe optical power and irradiance for Group I and II equipment, categorized by Equipment Group and temperature class Table 3 \u2013 Safe optical power and irradiance for Group III equipment <\/td>\n<\/tr>\n | ||||||
| 81<\/td>\n | Table 4 \u2013 Safe limit values for intermediate area, Group I or II, constant power, T1 \u2013 T4 atmospheres, equipment Groups IIA, IIB or IIC (Data derived from Figure B.1 including a safety factor) <\/td>\n<\/tr>\n | ||||||
| 83<\/td>\n | 5.2.3 Pulsed radiation <\/td>\n<\/tr>\n | ||||||
| 84<\/td>\n | 5.2.4 Ignition tests 5.2.5 Over-power\/energy fault protection <\/td>\n<\/tr>\n | ||||||
| 85<\/td>\n | 5.3 Requirements for protected optical radiation \u201cop pr\u201d 5.3.1 General 5.3.2 Radiation inside optical fibre or cable <\/td>\n<\/tr>\n | ||||||
| 86<\/td>\n | 5.3.3 Radiation inside enclosures 5.4 Optical system with interlock \u201cop sh\u201d <\/td>\n<\/tr>\n | ||||||
| 87<\/td>\n | 6 Type verifications and tests 6.1 Test set-up for ignition tests 6.1.1 General 6.1.2 Test vessel Figures Figure 1 \u2013 Optical ignition delay times and safe boundary curve with safety factor of 2 <\/td>\n<\/tr>\n | ||||||
| 88<\/td>\n | 6.1.3 Criteria to determine ignition 6.2 Verification of suitability of test set-up for type tests 6.2.1 Reference gas 6.2.2 Reference absorber 6.2.3 Reference test for continuous wave radiation and pulses above 1 s duration 6.2.4 Reference test for pulsed radiation below 1\u00a0ms pulse duration <\/td>\n<\/tr>\n | ||||||
| 89<\/td>\n | 6.3 Type tests 6.3.1 Ignition tests with continuous wave radiation and pulses above 1 s duration 6.3.2 Ignition tests with single pulses less than 1 ms duration 6.3.3 Tests for pulse trains and pulses from 1\u00a0ms to 1\u00a0s duration 6.3.4 Absorber targets for type tests <\/td>\n<\/tr>\n | ||||||
| 90<\/td>\n | 6.3.5 Test acceptance criteria and safety factors 7 Marking <\/td>\n<\/tr>\n | ||||||
| 92<\/td>\n | Annex A (informative) Reference test data Table A.1 \u2013 Reference values for ignition tests with a mixture of propane in air at 40 \u00b0C mixture temperature <\/td>\n<\/tr>\n | ||||||
| 93<\/td>\n | Annex B (informative) Ignition mechanisms <\/td>\n<\/tr>\n | ||||||
| 95<\/td>\n | Table B.1 \u2013 AIT (auto ignition temperature), MESG \n(maximum experimental safe gap) and measured ignition powers \nof the chosen combustibles for inert absorbers as the target \nmaterial (\u03b11 064 nm=83 %, \u03b1805 nm=93)3 <\/td>\n<\/tr>\n | ||||||
| 96<\/td>\n | Figure B.1 \u2013 Figure B.1 \u2013 Minimum radiant igniting power with inert absorber target \n(\u03b11064 nm=83 %, \u03b1805 nm=93 %) and continuous wave-radiation of 1064 nm <\/td>\n<\/tr>\n | ||||||
| 97<\/td>\n | Figure B.2 \u2013 Minimum radiant igniting power with inert absorber target \n(\u03b11 064 nm=83 %, \u03b1805 nm=93 %) and continuous wave-radiation \n(PTB: 1064 nm, HSL: 805 nm, [8]: 803 nm) for some n-alkanes Table B.2 \u2013 Comparison of measured minimum igniting optical pulse energy \n(Qe,p \ni,min) at 90 \u03bcm beam diameter with auto ignition temperatures (AIT) and minimum \nignition energies (MIE) from literature [9] at concentrations in percent by volume (\u03d5) <\/td>\n<\/tr>\n | ||||||
| 98<\/td>\n | Annex C (normative) Ignition hazard assessment Figure C.1 \u2013 Ignition hazard assessment <\/td>\n<\/tr>\n | ||||||
| 100<\/td>\n | Annex D (informative) Typical optical fibre cable design Figure D.1 \u2013 Example Multi-Fibre Optical Cable Design For Heavy Duty Applications Figure D.2 \u2013 Typical Single Optical Fibre Cable Design <\/td>\n<\/tr>\n | ||||||
| 101<\/td>\n | Annex E (normative) Flow diagram for the assessment of pulses Figure E.1 \u2013 Flow diagram for the assessment of pulses according to 5.2.3 <\/td>\n<\/tr>\n | ||||||
| 102<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Tracked Changes. Explosive atmospheres – Protection of equipment and transmission systems using optical radiation<\/b><\/p>\n |