International Standards and Conformity Assessment for all electrical, electronic and related technologies



Reference EN 50241-1:1999/A1:2004
Title Specification for open path apparatus for the detection of combustible or toxic gases and vapours - Part 1: General requirements and test methods
Project Number 15770
Abstract/Scope This European Standard specifies general requirements for the construction and testing of apparatus for the detection and measuring of combustible or toxic gases or vapours in ambient air by measuring the spectral absorption by the gases or vapours over extended optical paths, ranging typically from one meter to a few kilometers. Such apparatus measures the integral concentration of the absorbing gas over the optical path in units such as LEL meter for combustible gases and ppm meter for toxic gases. NOTE 1: Actual values of concentration can only be deduced where it can be established that the concentration is uniform over the optical path, as for example in very short optical paths (<100 mm). In such cases, the apparatus is within the scope of EN 50054 - EN 50058 and prEN 45544-1 to prEN 45544-4. Apparatus falling within the scope of this European Standard is classified as follows by the following types. Type 1: an optical transmitter and receiver, located at either end of a path through the atmosphere to be monitored. Type 2: an optical transceiver (i.e. combined transmitter and receiver) and a suitable reflector, which may be a topographic feature or a retroreflector, located at either end of a path through the atmosphere to be monitored. This European Standard does not apply to any of the following: 1. Apparatus intended to provide range resolution of gas concentration (e.g. LIDAR), 2. Apparatus consisting of a passive optical receiver without a dedicated optical source, 3. Apparatus intended to measure the local volumetric concentration of gas (point sensors), 4. Apparatus intended for the detection of dusts or mists in air, 5. Apparatus for cross stack monitoring, 6. Apparatus intended for the detection of explosives and vapours, and 7. Apparatus intended for quantitative and simultaneous multicomponent analysis, e.g. FTIR. This European Standard covering general requirements and test methods is supplemented by the following European Standard concerning specific requirements of performance: EN 50241-2: Performance requirements for apparatus for the detection of combustible gases. This European Standard is applicable to apparatus which is intended for use in both hazardous and non hazardous areas. Apparatus for use in hazardous areas which may contain potentially combustible atmospheres is required to be designed for safe operation, see 4.1.2. This European Standard applies to transportable, and fixed apparatus intended for commercial and industrial applications. NOTE 2: This European Standard and EN 50241-2 as referenced above are intended to provide for the supply of apparatus giving a level of performance suitable for general purpose applications. However, for specific applications a prospective purchaser or an appropriate authority may additionally require apparatus to be submitted to particular tests or approval. Such tests or approval are to be regarded as additional to and separate from the provisions from the European Standards


Current Stage code 6060
Current Stage code date 2004-02-17
Current Stage code deadline 2004-08-01
Deadline date for vote  


Directive(s) ATEX (94/9/EC)
Order Voucher  


IEC Technical Body IEC/TC 31
Reference Document  
ICS 13.320 - Alarm and warning systems
19.080 - Electrical and electronic testing
Keywords Combustible gas; Toxic gas and vapour; Open path apparatus; Detection; Test method
Note Superseded by EN 60079-29-4:2010
Special National Condition(s)  


Categories - Aspects
Product Life Cycle


Deadline Date
6060 2004-02-17 2004-08-01 export to doc file  EN
5099 2004-02-01 2004-06-01  
5061 2003-11-24 2004-02-01  
5020 2003-04-11 2003-10-10  
1090 2003-03-26 2003-09-26  

Implementation Dates

date of Ratification (DOR) (1) 2004-02-01
date of Availability (DAV) (2) 2004-02-17
date of Announcement (DOA) (3) 2004-08-01
date of Publication (DOP) (4) 2004-08-01
date of Withdrawal (DOW) (5) 2004-08-01


Superseded by EN 60079-29-4:2010
Normative reference (6)  

(1) Date of ratification (dor) date when the Technical Board notes the approval of an EN (and HD for CENELEC), from which time the standard may be said to be approved

(2) Date of availability (dav) date when the definitive text in the official language versions of an approved CEN/CENELEC publication is distributed by the Central Secretariat

(3) Date of announcement (doa) latest date by which the existence of an EN (and HD for CENELEC), a TS or a CWA has to be announced at national level

(4) Date of publication (dop) latest date by which an EN has to be implemented at national level by publication of an identical national standard or by endorsement

(5) Date of withdrawal (dow) latest date by which national standards conflicting with an EN (and HD for CENELEC) have to be withdrawn

(6) This list of normative references is purely indicative. The only official list of normative reference is the list of the published standard.