1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULNational Differences ForExplosive Atmospheres Part 29-4: Gas Detectors Performance Requirements of Open PathDetectors for Flammable GasesUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODU
2、CTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULNational Differences ForExplosive Atmospheres Part 29-4: Gas Detectors Performance Requirements of Open PathDetectors for Flammable GasesFirst EditionEdition Date: August 24, 2018Adoption of IEC 60079-29-4, Explosive Atmospheres Part 29-4: Gas Detectors
3、 PerformanceRequirements of Open Path Detectors for Flammable Gases (first edition issued by IECNovember 2009) as a new IEC-based UL standard, UL 60079-29-4 with US Differences.As noted in the Commitment for Amendments statement located on the back side of the titlepage, UL and FM are committed to u
4、pdating this harmonized standard jointly.This document provides a single listing of the National Differences included in the UL adoption ofthe corresponding IEC standard.All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, ortransmitted in any form by any
5、 means, electronic, mechanical photocopying, recording, or otherwisewithout prior permission of UL.UL provides this standards document as is without warranty of any kind, either expressed or implied,including but not limited to, the implied warranties of merchantability or fitness for any purpose.In
6、 no event will UL be liable for any special, incidental, consequential, indirect or similar damages,including loss of profits, lost savings, loss of data, or any other damages arising out of the use of or theinability to use this standards document, even if UL or an authorized UL representative has
7、been advisedof the possibility of such damage. In no event shall ULs liability for any damage ever exceed the pricepaid for this standards document, regardless of the form of the claim.Users of the electronic versions of ULs Standards for Safety agree to defend, indemnify, and hold ULharmless from a
8、nd against any loss, expense, liability, damage, claim, or judgment (including reasonableattorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronicStandard on the purchasers computer system.Copyright 2018 Underwriters Laboratories Inc.AUGUST 24, 2018NAT
9、IONAL DIFFERENCES FOR2UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULPrefaceThis document provides a single listing of the technical National Differences included in the UL adoptionof the corresponding IEC standard.In its IEC-based standards,
10、 UL uses the notations indicated below to identify national difference type, andthese types are additionally noted in this document. The standard may not use all types of thesedeviations.D1 - These are deviations which are based on basic safety principles and requirements, elimination ofwhich would
11、compromise safety for U.S. consumers and users of products.D2 - These are deviations based on safety practices. These are deviations for IEC requirements that maybe acceptable, but adopting the IEC requirements would require considerable retesting or redesign on themanufacturers part.DC - These are
12、deviations based on the component standards and will not be deleted until a particularcomponent standard is harmonized with the IEC component standard.DE - These are deviations based on editorial comments or corrections.DR - These are deviations based on the national regulatory requirements.Each nat
13、ional difference contains a description of what the national difference entails. Typically one of thefollowing words is used to explain how the text of the national difference is to be applied to the base IECtext:Addition / Add - An addition entails adding a complete new numbered clause, subclause,
14、table, figure,or annex. Addition is not meant to include adding select words to the base IEC text.Deletion / Delete - A deletion entails complete deletion of an entire numbered clause, subclause, table,figure, or annex without any replacement text.Modification / Modify - A modification is an alterin
15、g of the existing base IEC text such as the addition,replacement or deletion of certain words or the replacement of an entire clause, subclause, table, figure,or annex of the base IEC text.AUGUST 24, 2018 NATIONAL DIFFERENCES FOR 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDIS
16、TRIBUTION WITHOUT PERMISSION FROM ULNational Differences1DV.1 DR Modification of Clause 1, first paragraph to replace with the following:1DV.1.1 This part of IEC 60079-29 standard specifies performance requirements ofequipment for the detection and measuring of flammable gases or vapours in ambient
17、airby measuring the spectral absorption by the gases or vapours over extended optical paths,ranging typically from one metre to a few kilometres.1DV.2 DR Addition of 1DV.2.11DV.2.1 Where references are made to other IEC 60079 standards, the referencerequirements found in these standards apply as mod
18、ified by any applicable U.S. NationalDifferences.2DV DR Modification of Clause 2 references to replace with the following:ANSI/NFPA 497, Recommended Practice for Classification of Flammable Liquids, Gases, orVapors and of Hazardous (Classified) Locations for Electrical Installation in Chemical Proce
19、ssAreasIEC 60079 (all parts), Explosive atmospheresIEC 60079-0, Explosive atmospheres Part 0: Equipment General requirementsIEC 60079-29-1, Explosive atmospheres Part 29-1: Gas detectors Performance requirementsof detectors for flammable gasesIEC 60825-1, Safety of laser products Part 1: Equipment c
20、lassification and requirementsIEC 61000-4-1, Electromagnetic compatibility (EMC) Part 4-1: Testing and measurementtechniques Overview of IEC 61000-4 seriesIEC 61000-4-3, Electromagnetic compatibility (EMC) Part 4-3: Testing and measurementtechniques Radiated, radio-frequency, electromagnetic field i
21、mmunity testUL 60079-0 Explosive atmospheres Part 0: Equipment General requirements3DV DR Modification of Clause 3 to replace with the following:For the purposes of this document, the terms and definitions given in IEC 60079-0 UL60079-0 as well as IEC 60079-29-1 and the following apply.NOTE Addition
22、al definitions applicable to explosive atmospheres can be found in IEC 60050-426.AUGUST 24, 2018NATIONAL DIFFERENCES FOR4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL3.4.6DV D2 Modification of Clause 3.4.6 to replace with the following:3.4.
23、6 lower flammable limitLFLvolume ratio of flammable gas or vapour in air below which a flammable gas atmospherewill not be formed (see ANSI/NFPA 497)3.4.7DV D2 Modification of Clause 3.4.7 to replace with the following:3.4.7 upper flammable limitUFLvolume ratio of flammable gas or vapour in air abov
24、e which an explosive gas atmospherewill not be formed (see ANSI/NFPA 497)5.4.8.2.3DV.1 DE Modification of Clause 5.4.8.2.3, second paragraph to replace with thefollowing:The equipment shall not suffer any loss of function. False alarms, fault signals other thandue to mis-alignment, or damage resulti
25、ng in a hazard shall not occur. The measuredvalues of the integral concentration for each gas shall not differ from the nominal valuesby more than 10 % of the measuring range or 20 % of the measured value, whichever isgreater.NOTE Proper alignment is critical for open path gas detection; therefore,
26、sources of mis-alignment due to the testequipment should be taken into account if fault signals occur.5.4.11.1DV.1 DE Modification of Clause 5.4.11.1, fourth paragraph to replace with thefollowing:The sequence shall then be repeated except that the cell containing test gas shall berapidly removed or
27、 exchanged with cell of the same dimensions containing clean air. Therecovery time for the signal to decay to 10 % of the test gas reading shall be recorded.5.4.21ADV DR Addition of Clause 5.4.21ADV:5.4.21 Fault signalsWhen the apparatus has undergone each condition separately as specified in 4.2.4,
28、 theapparatus shall indicate a fault signal without a false alarm indication.5.4.22ADV DR Addition of Clause 5.4.22ADV:5.4.22 Verification of performance when environmental rating claims (alternative to therequirements of clause 7.2 u)The effects of the tests required to verify the apparatuss suitab
29、ility for specifiedenvironmental ratings (dust, rain, hose down, corrosion tests, etc.) shall be evaluated asfollows. Adjustable alarm apparatus shall be set to the lowest alarm level or 10 % of themeasuring range, whichever is greater. Cells as described in 5.2.4, filled to atmosphericAUGUST 24, 20
30、18 NATIONAL DIFFERENCES FOR 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULpressure with dry clean air, shall be introduced and indication recorded. The apparatusshall then be subjected to the applicable environmental test. The apparatus sha
31、ll not giveany false alarms during the test. Upon completion of the test, the apparatus shall be testedwith clean air and the initial calibration mixture, the reading shall be accurate within 7.5% of full-scale gas concentration or 15% of the initial measured value, whichever isgreater after this te
32、st. In lieu of the test criteria above, apparatus incorporating alarms onlyshall be actuated by a 24 to 26 % the full scale but not be actuated by a 14 to 16 % the fullscale after this test.7.1DV DE Modification of Clause 7.1 to replace with the following:The equipment shall comply with the marking
33、requirements of IEC 60079-0 UL 60079-0.NOTE Electrical equipment which does not fully comply with the relevant parts of IEC 60079-0 UL 60079-0 whereequivalent safety is claimed, should be marked with the symbol “s”.In addition, the equipment shall also be marked:a) “IEC 60079-29-4” (to represent con
34、formance with this performance standard);b) year of construction (may be encoded within the serial number).7.2DV.1 DR Modification of Clause 7.2, first paragraph to replace with the following:Each gas detection equipment, or each batch of equipment, shall be accompanied byinstructions as required by
35、 UL 60079-0, including the following additional particulars:7.2DV.2 DE Modification of Clause 7.2, second paragraph to add items u) and v) asfollows:u) if an ingress protection (IP) and/or corrosion resistance is claimed, such as IEC 60529or NEMA 250, the following statements shall be included:1) IP
36、 and/or corrosion resistance ratings do not imply that the equipment willdetect gas during and immediately after exposure to those conditions.2) recommendations for determining appropriate calibration interval andmaintenance requirements if exposed to those conditions representative of the IPand/or corrosion resistance rating.3) list of accessories for which the IP and/or corrosion resistance rating isdependent.v) claimed reference to FM 60079-29-4 /UL 60079-29-4 to represent conformance with thisperformance standard.AUGUST 24, 2018NATIONAL DIFFERENCES FOR6
