This part of ISO\/IEC 80079 describes the test methods for the identification of combustible dust and combustible dust layers in order to permit classification of areas where such materials exist for the purpose of the proper selection and installation of electrical and mechanical equipment for use in the presence of combustible dust.<\/p>\n
The standard atmospheric conditions for determination of characteristics of combustible dusts are:<\/p>\n
temperature \u201320 \u00b0C to +60 \u00b0C,<\/p>\n<\/li>\n
pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar) and<\/p>\n<\/li>\n
air with normal oxygen content, typically 21 % v\/v.<\/p>\n<\/li>\n<\/ul>\n
The test methods defined do not apply to:<\/p>\n
recognized explosives, propellants (e.g. gunpowder, dynamite), or substances or mixtures of substances which may, under some circumstances, behave in a similar manner or<\/p>\n<\/li>\n
dusts of explosives and propellants that do not require atmospheric oxygen for combustion, or to pyrophoric substances.<\/p>\n<\/li>\n<\/ul>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4 Dust sample requirements 4.1 Receipt of sample for testing 4.2 Characterisation of sample <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.3 Preparation of sample 4.4 Test conditions 5 Combustible dusts and combustible flyings determination 5.1 Test sequence 5.2 Tests to determine whether material is a combustible dust or combustible flying 5.2.1 Visual inspection <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5.2.2 Determine particle distribution 5.2.3 Ignition test in the Hartmann tube 5.2.4 Ignition test in the 20-litre sphere 6 Procedure for characterisation of combustible dust or combustible flying <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | Figures Figure 1 \u2013 Protocol for characterisation of combustible dust or combustible flying <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Figure 2 \u2013 Tests to define ability to form explosive dust atmosphere (combustible dust\/combustible flyings) <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 7 Test methods for determination of whether a material is a combustible dust or a combustible flying 7.1 Modified Hartmann tube 7.1.1 General 7.1.2 Test equipment Figure 3 \u2013 Tests to characterise combustible dust or combustible flying <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 7.1.3 Test procedure 7.2 20-litre sphere 7.2.1 General 7.2.2 Test equipment <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 7.2.3 Test procedure 7.3 Alternative method to 20-litre sphere for small test material quantities 7.3.1 General <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 7.3.2 Test equipment 7.3.3 Test procedure 8 Test methods for combustible dust determinations 8.1 MIT of a dust cloud 8.1.1 General 8.1.2 GG furnace <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 8.1.3 BAM furnace <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 8.2 Test for MIT of dust layer 8.2.1 General 8.2.2 Heated surface <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 8.2.3 Dust layers 8.2.4 Dust layer temperature 8.2.5 Ambient temperature measurements 8.2.6 Dust layer temperature test method <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 8.2.7 Recording of results Tables Table 1 \u2013 Example of ignition test report <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 8.3 Method for determining minimum ignition energy of dust\/air mixtures 8.3.1 General 8.3.2 Test equipment <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 8.3.3 Test procedure Figure 4 \u2013 Modified Hartmann tube <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 8.3.4 Calibration for determination of minimum ignition energies (MIE) by electrically generated high-voltage d.c. sparks 8.3.5 Recording of test results 8.4 Test on resistivity 8.4.1 General <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 8.4.2 Test equipment 8.4.3 Test procedure Figure 5 \u2013 Measuring cell for powder resistivity <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 8.4.4 Recording of test results 9 Test report <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Annexes Annex A (normative) Measurement of temperature distribution on the surface of the hot plate Figure A.1 \u2013 Typical surface temperature distribution (method A) <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Annex B (informative) Godbert-Greenwald oven (GG) Figure B.1 \u2013 Vertical cross-section through the Godbert-Greenwald oven <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Annex C (informative) Examples of spark-generating systems C.1 General Figure C.1 \u2013 Circuit \u2013 Triggering by high-voltage relay, using a two-electrode system <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | C.2 Triggering by auxiliary spark using three-electrode system Figure C.2 \u2013 Apparatus for determining the minimum ignition energies of dust (schematic) \u2013 Triggering by auxiliary spark using three-electrode system <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | C.3 Triggering by electrode movement Figure C.3 \u2013 Apparatus for determining the minimum ignition energiesof dust (schematic) \u2013 Triggering by electrode movement <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | C.4 Triggering by voltage increase (trickle-charging circuit) Figure C.4 \u2013 Apparatus for determining the minimum ignition energies of dust (schematic) \u2013 Triggering by voltage increase <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | C.5 Triggering by auxiliary spark, using normal two-electrode system \u2013 Trigger transformer in discharge circuit Figure C.5 \u2013 Apparatus for determining the minimum ignition energies for dust (schematic) \u2013 Trigger transformer in discharge circuit <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Annex D (normative) Vertical tube (modified Hartmann tube) apparatus Figure D.1 \u2013 Vertical tube apparatus (modified Hartmann tube) <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | Annex E (informative) 20-litre sphere Figure E.1 \u2013 Test equipment 20-litre sphere (schematic) <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | Figure E.2 \u2013 Cross-sectional view of rebound nozzle Figure E.3 \u2013 Plan view of rebound nozzle Figure E.4 \u2013 Cross-sectional view of dispersion cup <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Annex F (informative) BAM oven Figure F.1 \u2013 Cross-sectional arrangement of BAM oven <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | Annex G (informative) Data for dust explosion characteristics <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Annex H (informative) 1 m3 vessel H.1 Test principle H.2 Test apparatus <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Figure H.1 \u2013 1 m3 vessel (schematic) <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Figure H.2 \u2013 Location of the 6 mm holes in the semicircular dust dispenser <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | Figure H.3 \u2013 Rebound nozzle <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | H.3 Test conditions H.4 Test procedure Figure H.4 \u2013 Dispersion cup <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Explosive atmospheres – Material characteristics. Combustible dusts test methods<\/b><\/p>\n |