标准编号:	GB/T 50493-2019
中文名称:	石油化工可燃气体和有毒气体检测报警设计标准
英文名称:	Standard for design of combustible gas and toxic gas detection and alarm for petrochemical industry
行业分类:	GB    国家标准
发布机构:	中华人民共和国住房和城乡建设部
发布日期:	2019-09-25
实施日期:	2020-1-1
标准状态:	valid
替代旧标准:	GB 50493-2009 石油化工可燃气体和有毒气体检测报警设计规范
翻译语言:	英文
文件格式:	PDF
中文字符数:	33000 字
翻译价格(元):	2310.0
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is revised from GB 50493-2009 Specification for design of combustible gas and toxic gas detection and alarm for petrochemical industry by Sinopec Guangzhou Engineering Co., Ltd. jointly with organizations concerned according to the requirements of Document JIANBIAO [2015] No.274 issued by the Ministry of Housing and Urban-Rural Development of the People's Republic of China - Notice on Printing and Distributing the ‘Development and Revision Plan on Engineering Construction Standards and Codes in 2016’. During the revision of this standard, the standard drafting group made extensive investigations and studies on the problems encountered in the design of combustible gas and toxic gas detection and alarm for petrochemical industry, summarized the experience in the use of combustible gas detectors and toxic gas detectors in petrochemical enterprises in recent years, and finalized this standard after examination finally by reference to the European standard EN 60079-29-2 Explosive atmospheres - Part 29-2: Gas detectors - Selection, installation, use and maintenance of detectors for flammable gases and oxygen and on the basis of soliciting opinions from design, production, scientific research, detector manufacturing enterprises and other relevant parties. The main technical contents of this standard are: general provisions, terms, basic requirements, location of detection points, design of combustible gas and toxic gas detection and alarm system, installation of combustible gas and toxic gas detection and alarm system, etc. The main technical contents of the revision of this standard are: 1. The scope of application of the standard is revised from “construction, extension and renovation engineerings of petrochemical industry" to "construction and extension engineerings of petrochemical industry"; 2. The scope of toxic gases is expanded from toxic gases listed in the Catalogue of highly toxic articles to common toxic gases; 3. The requirements for design compatibility, independence and reliability of combustible gas and toxic gas detection and alarm system (GDS) are added; 4. The requirements for separately setting the combustible gas and toxic gas detection and alarm system (GDS) and the fire fighting and fire automation system are added; 5. Open-path (laser, infrared) detectors, noise detectors and other contents are added, and the detection point and layout requirements of detectors are further improved; 6. Guide for the selection of common gas detectors as well as the arrangement plan of combustible gas and toxic gas detection and alarm system are added. The Ministry of Housing and Urban-Rural Development of the People's Republic of China is in charge of the administration of this standard, China Petrochemical Corporation is responsible for the routine management, and Sinopec Guangzhou Engineering Co., Ltd. is responsible for the explanation of specific technical contents. During the process of implementing this standard, you are kindly requested to send your opinions and advice (if any) to Sinopec Guangzhou Engineering Co., Ltd. (Address: F20, Tower A, Guangzhou Sinopec Building, No.191, West Tiyu Road, Tianhe District, Guangzhou City, Guangdong Province, 510620, China). Contents 1 General provisions 1 2 Terms 2 3 Basic requirements 4 4 Location of detection points 6 4.1 General requirements 6 4.2 Process units 7 4.3 Storage and transportation facilities 7 4.4 Other places where combustible gases, toxic gases diffuse and accumulate 8 5 Design of combustible gas and toxic gas detection and alarm system 10 5.1 General requirements 10 5.2 Selection of detector 10 5.3 Selection of field alarming units 11 5.4 Selection of alarm control unit 12 5.5 Measurement range and setting of alarm value 13 6 Installation of combustible gas and toxic gas detection and alarm system 15 6.1 Installation of detector 15 6.2 Installation of alarm control unit and field alarming unit 15 Annex A Properties of common combustible gases and vapors 16 Annex B Properties of common toxic gases and vapors 21 Annex C Arrangement plan of combustible gas and toxic gas detection and alarm system 22 Annex D Technical performance table of common gas detectors 23 Annex E Guide for selection of common gas detectors 25 Explanation of wording in this standard 26 List of quoted standards 27 1 General provisions 1.0.1 This standard is formulated with a view to ensuring the personal safety and production safety of petrochemical enterprises, monitoring combustible gases or toxic gases leaked during the production process and in storage and transportation facilities and timely alarming to prevent personal injury and fire and explosion accidents. 1.0.2 This standard is applicable to the design of combustible gas and toxic gas detection and alarm system for construction and extension engineerings of petrochemical industry. 1.0.3 In addition to the requirements of this standard, the design of combustible gas and toxic gas detection and alarm system for petrochemical industry shall also comply with those stipulated in the current relevant standards of the nation.   2 Terms 2.0.1 combustible gas combustible gas or vapour formed after gasification of Class A gas or Classes A and BA combustible liquids, which is also known as flammable gas 2.0.2 toxic gas toxic gas or vapor that may cause death or permanent health injury of workers through skin contact or breathing during professional activities 2.0.3 source of release location or place where explosive gas atmosphere and toxic gas atmosphere may be released and formed 2.0.4 detector an electronic device that converts the concentration of combustible gas, toxic gas or oxygen into electrical signals 2.0.5 open-path gas detector an open type gas detector for detecting combustible gas or toxic gas clouds in a straight path. Commonly used open-path gas detectors include: infrared gas detectors, laser gas detectors, etc. 2.0.6 field alarming unit/audible and visual alarm unit an electronic device installed on the site to alert personnel on or near the site by sound, light, or optical rotation. Common ones include: the integrated audible and visual alarm unit on the detector, and the field alarming unit set by zone 2.0.7 alarm control unit an electronic device that receives the output signal of the detector, displays and records the concentration of the detected gas, emits audible and visual alarm signals, and can send gas concentration alarm signal and alarm control unit fault information to equipment such as graphic display device in the fire control room. When the combustible gas alarm signal is involved in the fire control linkage, the alarm control unit usually adopts a special combustible gas alarm controller that is manufactured according to the product standard for the special combustible gas alarm controller and has been provided with the detection report 2.0.8 sensible range the concentration range of the detected gas that the detector can detect, which is also called measurement range 2.0.9 alarm set point the preset alarm concentration value, which is divided into primary alarm set point and secondary alarm set point 2.0.10 response time the time from the detector contacting the detected gas to reaching stable indication under test conditions. Usually, the response time is the time required for reaching 90% of the stable indication, and the recovery time is the time required for returning to 10% of the stable indication 2.0.11 vertical height vertical distance from the suction inlet of the detector sensor to the specified reference 2.0.12 lower explosion limit (LEL) the lower concentration (V%) limit of a combustible gas when it explodes 2.0.13 upper explosion limit (UEL) the upper concentration (V%) limit of a combustible gas when it explodes 2.0.14 occupational exposure limit (OEL) the allowable exposure level of a worker that will not cause harmful health effects on the majority of contacts during his/her long-term repeated exposure in the occupational activities. The occupational exposure limits of chemical factors can be divided into three types: maximum allowable concentration, permissible concentration-short term exposure limit and permissible concentration-time weighted average 2.0.15 maximum allowable concentration (MAC) the concentration of toxic chemicals that cannot be exceeded at workplace at any time within a working day 2.0.16 permissible concentration-time weighted average (PC-TWA) the average permissible exposure concentration for 40h per working week (i.e., 8h per working day), with time as the weight 2.0.17 permissible concentration-short term exposure limit (PC-STEL) the permissible short term (15min) exposure concentration subject to the permissible concentration-time weighted average (PC-TWA) 2.0.18 immediately dangerous to life or health concentration (IDLH) certain dangerous level of the concentration of air pollutants in the environment at workplace, which may cause death or permanent health damage, or may make human immediately lose escape ability   3 Basic requirements 3.0.1 In the areas of the process units producing or using combustible gases and toxic gases and the storage and transportation facilities for combustible gases and toxic gases, when the concentration of combustible gas in the leaked gas may reach the alarm set point, the combustible gas detector shall be set; when the concentration of toxic gas in the leaked gas may reach the alarm set point, the toxic gas detector shall be set; in case of the single-component gas medium that belongs to both combustible gas and toxic gas, the toxic gas detector shall be set; in case of the multi-component mixed gas containing both combustible gas and toxic gas, when the concentration of combustible gas and that of toxic gas may reach the respective alarm set points at the same time during leakage, combustible gas detector and toxic gas detector shall be set respectively. 3.0.2 Two-level alarm shall be adopted for detection and alarm of combustible gas and toxic gas. When an alarm is sent for the toxic gas and combustible gas at the same level at the same time, the alarm level of toxic gas shall take precedence. 3.0.3 The detection and alarm signals for combustible gas and toxic gas shall be sent to the attended field control room and central control room for display and alarm. The secondary alarm signal of combustible gas and the fault signal of alarm control unit in combustible gas and toxic gas detection and alarm system shall be sent to the fire control room. 3.0.4 The operation area of the control room shall be provided with audible and visual alarm for combustible gas and toxic gas; the field alarming unit should be set according to the occupied area of the unit, the layout of equipment, buildings and structures, the physical and chemical properties of the source of release and the field air flow characteristics, which shall have audible and visual alarm functions. 3.0.5 The combustible gas detectors must be provided with the type approval certificate for measuring instruments, the explosion-proof certificate and the type inspection report for fire-fighting products issued by the organization designated by the nation or its authorized inspection unit; the alarm control unit involved in fire control linkage shall be the special combustible gas alarm controller that is manufactured according to the product standard for the special combustible gas alarm controller and has been provided with the detection report; the toxic gas detectors required by the national regulations must be provided with the type approval certificate for measuring instruments issued by the organization designated by the nation or its authorized inspection unit. Toxic gas detectors installed in explosive hazardous areas shall also be provided with the explosion-proof certificate issued by organization designated by the nation or its authorized inspection unit. 3.0.6 Where combustible gas and toxic gas detectors need to be set, stationary detectors should be adopted. Where it is necessary to temporarily detect the combustible gas and toxic gas, transportable gas detectors should be equipped. 3.0.7 Field workers entering explosive gas atmosphere or toxic gas atmosphere shall be equipped with portable combustible gas and (or) toxic gas detectors. When explosive gas and toxic gas coexist simultaneously in the atmosphere entered, the multi-sensor type portable combustible gas and toxic gas detectors may be adopted. 3.0.8 The combustible gas and toxic gas detection and alarm system shall be set independently of other systems. 3.0.9 The gas detectors, alarm control units, field alarming units, etc. in the combustible gas and toxic gas detection and alarm system shall be considered as particular important power supply loads among Class I electrical loads, and should be powered by UPS device. 3.0.10 The occupational exposure limit of toxic gas shall be selected in priority order of the maximum allowable concentration, the permissible concentration-time weighted average and then the permissible concentration-short term exposure limit. 3.0.11 The properties of common flammable gases and vapors shall be adopted according to Annex A hereto; and the properties of common toxic gases and vapors shall be adopted according to Annex B hereto.

1 General provisions 2 Terms 3 Basic requirements 4 Location of detection points 4.1 General requirements 4.2 Process units 4.3 Storage and transportation facilities 4.4 Other places where combustible gases, toxic gases diffuse and accumulate 5 Design of combustible gas and toxic gas detection and alarm system 5.1 General requirements 5.2 Selection of detector 5.3 Selection of field alarming units 5.4 Selection of alarm control unit 5.5 Measurement range and setting of alarm value 6 Installation of combustible gas and toxic gas detection and alarm system 6.1 Installation of detector 6.2 Installation of alarm control unit and field alarming unit Annex A Properties of common combustible gases and vapors Annex B Properties of common toxic gases and vapors Annex C Arrangement plan of combustible gas and toxic gas detection and alarm system Annex D Technical performance table of common gas detectors Annex E Guide for selection of common gas detectors Explanation of wording in this standard List of quoted standards

1 总 则 1.0.1 为保障石油化工企业的人身安全和生产安全，监测生产过程及储运设施中泄漏的可燃气体或有毒气体.并及时报警，预防人身伤害以及火灾与爆炸事故的发生，制定本标准。 1.0.2 本标准适用于石油化工新建、扩建工程中可燃气体和有毒气体检测报警系统的设计。 1.0.3 石油化工可燃气体和有毒气体检测报警系统的设计，除应符合本标准要求外，尚应符合国家现行有关标准的规定。 2 术 语 2.0.1 可燃气体 flammable gas 又称易燃气体，甲类气体或甲、乙A类可燃液体气化后形成的可燃气体或可燃蒸气。 2.0.2 有毒气体 toxic gas 劳动者在职业活动过程中，通过皮肤接触或呼吸可导致死亡或永久性健康伤害的毒性气体或毒性蒸气。 2.0.3 释放源 source of release 可释放并能形成爆炸性气体环境、有毒气体环境的位置或地点。 2.0.4 探测器detector 又称检测器，将可燃气体、有毒气体或氧气的浓度转换为电信号的电子设备。 2.0.5 线型气体探测器 open-path gas detector 一种开放式、用于检测直线路径中可燃气体或有毒气体云团的气体探测器。常用的线性气体探测器有：红外气体探测器、激光气体探测器等。 2.0.6 现场警报器 field alarming unit/audible and visual alarm unit 安装在现场，通过声、光或旋光向现场或接近现场人员发出警示的电子设备。常见的有：探测器自带的一体化的声、光警报器，按区域设置的现场区域警报器。 2.0.7报警控制单元 alarm control unit 接收探测器的输出信号、显示和记录被检测气体的浓度、发出声光报警信号，并能向消防控制室图形显示装置等设备发送气体浓度报警信号和报警控制单元故障信息的电子设备。可燃气体报警信号参与消防联动时，报警控制单元通常采用按专用可燃气体报警控制器产品标准制造并取得检测报告的专用可燃气体报警控制器。 2.0.8检测范围 sensible range 又称测量范围，探测器能够检测出被测气体的浓度范围。 2.0.9报警设定值 alarm set point 预先设定的报警浓度值。报警设定值分为一级报警设定值和二级报警设定值。 2.0.10 响应时间 response time 在试验条件下，从探测器接触被测气体至达到稳定指示值的时间。通常达到稳定指示值90％的时间为响应时间，恢复到稳定指示值10％的时间为恢复时间。 2.0.11 安装高度 vertical height 探测器传感器吸入口到指定参照物的垂直距离。 2.0.12爆炸下限lower explosion limit(LEL) 可燃气体发生爆炸时的下限浓度(V％)值。 2.0.13 爆炸上限 upper explosion limit(UEL) 可燃气体发生爆炸时的上限浓度(V％)值。 2.0.14职业接触限值 occupational exposure limit(OEL) 劳动者在职业活动中长期反复接触，不会对绝大多数接触者的健康引起有害作用的容许接触水平。化学因素的职业接触限值分为最高容许浓度、短时间接触容许浓度和时间加权平均容许浓度三种。 2.0.15 最高容许浓度 maximum allowable concentration(MAC) 工作地点在一个工作日内、任何时间有毒化学物质均不应超过的浓度。 2.0.16 时间加权平均容许浓度permissibie concentration-time weighted average(PC-TWA) 以时间为权数规定的8h工作日、40h工作周的平均容许接触浓度。 2.0.17 短时间接触容许浓度permissible concentration-short term exposure limit(PC-STEL) 在遵守时间加权平均容许浓度(PC-TWA)前提下容许短时间(15 min)接触的浓度。 2.0.18 直接致害浓度 immediately dangerous to life or health concentration(IDLH) 在工作地点，环境中空气污染物浓度达到某种危险水平，如可致命或永久损害健康，或使人立即丧失逃生能力。 3 基本规定 3.0.1 在生产或使用可燃气体及有毒气体的生产设施及储运设施的区域内，泄漏气体中可燃气体浓度可能达到报警设定值时，应设置可燃气体探测器；泄漏气体中有毒气体浓度可能达到报警设定值时，应设置有毒气体探测器；既属于可燃气体又属于有毒气体的单组分气体介质.应设有毒气体探测器；可燃气体与有毒气体同时存在的多组分混合气体.泄漏时可燃气体浓度和有毒气体浓度有可能同时达到报警设定值，应分别设置可燃气体探测器和有毒气体探测器。 3.0.2 可燃气体和有毒气体的检测报警应采用两级报警。同级别的有毒气体和可燃气体同时报警时，有毒气体的报警级别应优先。 3.0.3 可燃气体和有毒气体检测报警信号应送至有人值守的现场控制室、中心控制室等进行显示报警；可燃气体二级报警信号、可燃气体和有毒气体检测报警系统报警控制单元的故障信号应送至消防控制室。 3.0.4 控制室操作区应设置可燃气体和有毒气体声、光报警；现场区域警报器宜根据装置占地的面积、设备及建构筑物的布置、释放源的理化性质和现场空气流动特点进行设置，现场区域警报器应有声、光报警功能。 3.0.5 可燃气体探测器必须取得国家指定机构或其授权检验单位的计量器具型式批准证书、防爆合格证和消防产品型式检验报告；参与消防联动的报警控制单元应采用按专用可燃气体报警控制器产品标准制造并取得检测报告的专用可燃气体报警控制器；国家法规有要求的有毒气体探测器必须取得国家指定机构或其授权检验单位的计量器具型式批准证书。安装在爆炸危险场所的有毒气体探测器还应取得国家指定机构或其授权检验单位的防爆合格证。 3.0.6 需要设置可燃气体、有毒气体探测器的场所，宜采用固定式探测器；需要临时检测可燃气体、有毒气体的场所，宜配备移动式气体探测器。 3.0.7 进入爆炸性气体环境或有毒气体环境的现场工作人员，应配备便携式可燃气体和(或)有毒气体探测器。进入的环境同时存在爆炸性气体和有毒气体时，便携式可燃气体和有毒气体探测器可采用多传感器类型。 3.0.8 可燃气体和有毒气体检测报警系统应独立于其他系统单独设置。 3.0.9 可燃气体和有毒气体检测报警系统的气体探测器、报警控制单元、现场警报器等的供电负荷，应按一级用电负荷中特别重要的负荷考虑，宜采用UPS电源装置供电。 3.0.10 确定有毒气体的职业接触限值时，应按最高容许浓度、时间加权平均容许浓度、短时间接触容许浓度的优先次序选用。 3.0.11 常见易燃气体、蒸气特性应按本标准附录A采用：常见有毒气体、蒸气特性应按本标准附录B采用。 4检测点确定 4.1 一般规定 4.1.1 可燃气体和有毒气体探测器的检测点，应根据气体的理化性质、释放源的特性、生产场地布置、地理条件、环境气候、探测器的特点、检测报警可靠性要求、操作巡检路线等因素进行综合分析，选择可燃气体及有毒气体容易积聚、便于采样检测和仪表维护之处布置。 4.1.2 判别泄漏气体介质是否比空气重，应以泄漏气体介质的分子量与环境空气的分子量的比值为基准，并应按下列原则判别： 1 当比值大于或等于1.2时，则泄漏的气体重于空气； 2 当比值大于或等于1.0、小于1.2时，则泄漏的气体为略重于空气； 3 当比值为0.8～1.0时，则泄漏的气体为略轻于空气； 4 当比值小于或等于0.8时，则泄漏的气体为轻于空气。 4.1.3 下列可燃气体和(或)有毒气体释放源周围应布置检测点： 1 气体压缩机和液体泵的动密封； 2 液体采样口和气体采样口； 3 液体(气体)排液(水)口和放空口； 4 经常拆卸的法兰和经常操作的阀门组。 4.1.4 检测可燃气体和有毒气体时，探测器探头应靠近释放源，且在气体、蒸气易于聚集的地点。 4.1.5 当生产设施及储运设施区域内泄漏的可燃气体和有毒气体可能对周边环境安全有影响需要监测时，应沿生产设施及储运设施区域周边按适宜的间隔布置可燃气体探测器或有毒气体探测器，或沿生产设施及储运设施区域周边设置线型气体探测器。 4.1.6 在生产过程中可能导致环境氧气浓度变化，出现欠氧、过氧的有人员进入活动的场所，应设置氧气探测器。当相关气体释放源为可燃气体或有毒气体释放源时，氧气探测器可与相关的可燃气体探测器、有毒气体探测器布置在一起。 4.2生产设施 4.2.1 释放源处于露天或敞开式厂房布置的设备区域内，可燃气体探测器距其所覆盖范围内的任一释放源的水平距离不宜大于10 m，有毒气体探测器距其所覆盖范围内的任一释放源的水平距离不宜大于4 m。 4.2.2 释放源处于封闭式厂房或局部通风不良的半敞开厂房内，可燃气体探测器距其所覆盖范围内的任一释放源的水平距离不宜大于5m；有毒气体探测器距其所覆盖范围内的任一释放源的水平距离不宜大于2m。 4.2.3 比空气轻的可燃气体或有毒气体释放源处于封闭或局部通风不良的半敞开厂房内，除应在释放源上方设置探测器外，还应在厂房内最高点气体易于积聚处设置可燃气体或有毒气体探测器。 4.3储运设施 4.3.1 液化烃、甲B、乙A类液体等产生可燃气体的液体储罐的防火堤内，应设探测器。可燃气体探测器距其所覆盖范围内的任一释放源的水平距离不宜大于10m，有毒气体探测器距其所覆盖范围内的任一释放源的水平距离不宜大于4m。 4.3.2 液化烃、甲B、乙A类液体的装卸设施，探测器的设置应符合下列规定： 1 铁路装卸栈台，在地面上每一个车位宜设一台探测器，且探测器与装卸车口的水平距离不应大于10m； 2 汽车装卸站的装卸车鹤位与探测器的水平距离不应大于10m。 4.3.3 装卸设施的泵或压缩机区的探测器设置，应符合本标准第4.2节的规定。 4.3.4 液化烃灌装站的探测器设置，应符合下列规定： 1 封闭或半敞开的灌瓶间，灌装口与探测器的水平距离宜为5m～7.5 m； 2 封闭或半敞开式储瓶库，应符合本标准第4.2.2条规定；敞开式储瓶库房沿四周每隔15 m～20m应设一台探测器，当四周边长总和小于15 m时，应设一台探测器； 3 缓冲罐排水口或阀组与探测器的水平距离宜为5m～7.5 m。 4.3.5 封闭或半敞开氢气灌瓶间，应在灌装口上方的室内最高点易于滞留气体处设探测器。 4.3.6 可能散发可燃气体的装卸码头，距输油臂水平平面10m范围内，应设一台探测器。 4.3.7 其他储存、运输可燃气体、有毒气体的储运设施，可燃气体探测器和(或)有毒气体探测器应按本标准第4.2节的规定设置。 4.4其他有可燃气体、有毒气体的扩散与积聚场所 4.4.1 明火加热炉与可燃气体释放源之间应设可燃气体探测器，探测器距加热炉炉边的水平距离宜为5 m~10m。当明火加热炉与可燃气体释放源之间设有不燃烧材料实体墙时，实体墙靠近释放源的一侧应设探测器。 4.4.2 设在爆炸危险区域2区范围内的在线分析仪表间，应设可燃气体和(或)有毒气体探测器，并同时设置氧气探测器。 4.4.3 控制室、机柜间的空调新风引风口等可燃气体和有毒气体有可能进入建筑物的地方，应设置可燃气体和(或)有毒气体探测器。 4.4.4 有人进入巡检操作且可能积聚比空气重的可燃气体或有毒气体的工艺阀井、管沟等场所，应设可燃气体和(或)有毒气体探测器。 5 可燃气体和有毒气体检测报警系统设计 5.1 一般规定 5.1.1 可燃气体和有毒气体检测报警系统应由可燃气体或有毒气体探测器、现场警报器、报警控制单元等组成。 5.1.2 可燃气体的第二级报警信号和报警控制单元的故障信号，应送至消防控制室进行图形显示和报警。可燃气体探测器不能直接接入火灾报警控制器的输入回路。 5.1.3 可燃气体或有毒气体检测信号作为安全仪表系统的输入时.探测器宜独立设置，探测器输出信号应送至相应的安全仪表系统.探测器的硬件配置应符合现行国家标准《石油化工安全仪表系统设计规范》GB/T 50770有关规定。 5.1.4 可燃气体和有毒气体检测报警系统配置图见本标准附录C。 5.2探测器选用 5.2.1 探测器的输出可选用4 mA～20mA的DC信号、数字信号、触点信号。 5.2.2 可燃气体及有毒气体探测器的选用，应根据探测器的技术性能、被测气体的理化性质、被测介质的组分种类和检测精度要求、探测器材质与现场环境的相容性、生产环境特点等确定。 5.2.3 常用可燃气体及有毒气体探测器的选用应符合下列规定： 1 轻质烃类可燃气体宜选用催化燃烧型或红外气体探测器；当使用场所的空气中含有能使催化燃烧型检测元件中毒的硫、磷、硅、铅、卤素化合物等介质时，应选用抗毒性催化燃烧型探测器、红外气体探测器或激光气体探测器；在缺氧或高腐蚀性等场所，宜选用红外气体探测器或激光气体探测器；重质烃类蒸气可选用光致电离型探测器； 2 氢气检测宜选用催化燃烧型、电化学型、热传导型探测器； 3 有机有毒气体宜选用半导体型、光致电离型探测器； 4 无机有毒气体检测宜选用电化学型探测器； 5 氧气宜选用电化学型探测器； 6 在气候环境或生产环境特殊，需监测的区域开阔的场所，宜选择线型可燃气体探测器； 7 在工艺介质泄漏后形成的气体或蒸气能显著改变释放源周围环境温度的场所，可选用红外图像型探测器； 8 在高压工艺介质泄漏时产生的噪声能显著改变释放源周围环境声压级的场所，可选用噪声型探测器； 9 在生产和检修过程中需要临时检测可燃气体、有毒气体的场所，应配备移动式气体探测器。 5.2.4 常用探测器的采样方式应根据使用场所按下列规定确定： 1 可燃气体和有毒气体的检测宜采用扩散式探测器； 2 受安装条件和介质扩散特性的限制，不便使用扩散式探测器的场所，可采用吸入式探测器； 3 当探测器配备采样系统时，采样系统的滞后时间不宜大于30s。 5.2.5 常见气体探测器的技术性能应符合本标准附录D的要求；常见气体探测器应按照本标准附录E选用。 5.3 现场警报器选用 5.3.1 可燃气体和有毒气体检测报警系统应按照生产设施及储运设施的装置或单元进行报警分区，各报警分区应分别设置现场区域警报器。区域警报器的启动信号应采用第二级报警设定值信号。区域警报器的数量宜使在该区域内任何地点的现场人员都能感知到报警。 5.3.2 区域警报器的报警信号声级应高于110dBA，且距警报器1 m处总声压值不得高于120dBA。 5.3.3 有毒气体探测器宜带一体化的声、光警报器，可燃气体探测器可带一体化的声、光警报器，一体化声、光警报器的启动信号应采用第一级报警设定值信号。 5.4 报警控制单元选用 5.4.1 报警控制单元应采用独立设置的以微处理器为基础的电子产品，并应具备下列基本功能： 1 能为可燃气体探测器、有毒气体探测器及其附件供电。 2 能接收气体探测器的输出信号，显示气体浓度并发出声、光报警。 3 能手动消除声、光报警信号，再次有报警信号输入时仍能发出报警。 4 具有相对独立、互不影响的报警功能，能区分和识别报警场所位号。 5 在下列情况下，报警控制单元应能发出与可燃气体和有毒气体浓度报警信号有明显区别的声、光故障报警信号： 1)报警控制单元与探测器之间连线断路或短路。 2)报警控制单元主电源欠压。 3)报警控制单元与电源之间的连线断路或短路。 6 具有以下记录、存储、显示功能： 1)能记录可燃气体和有毒气体的报警时间，且日计时误差不应超过30s； 2)能显示当前报警部位的总数； 3)能区分最先报警部位，后续报警点按报警时间顺序连续显示； 4)具有历史事件记录功能。 5.4.2 控制室内可燃气体和有毒气体声、光警报器的声压等级应满足设备前方1 m处不小于75 dBA，声、光警报器的启动信号应采用第二级报警设定值信号。 5.4.3 可燃气体探测器参与消防联动时，探测器信号应先送至按专用可燃气体报警控制器产品标准制造并取得检测报告的专用可燃气体报警控制器.报警信号应由专用可燃气体报警控制器输出至消防控制室的火灾报警控制器。可燃气体报警信号与火灾报警信号在火灾报警控制系统中应有明显区别。