EN 50073:1999

Foreword
1 Scope
2 Normative references
3 Definitions
4 Intended application
    4.1 General
    4.2 Performance testing
    4.3 Electrical testing and certification for
          use of apparatus in potentially explosive
          atmospheres
    4.4 Fixed apparatus and fixed systems
    4.5 Transportable apparatus
    4.6 Portable apparatus
    4.7 Sampling lines and sampling probes
    4.8 Filters
    4.9 Flame arrestors
5 Criteria of selection
    5.1 General
    5.2 Catalytic sensor
    5.3 Thermal conductivity sensor
    5.4 Infrared sensor
    5.5 Semicondutor sensor
    5.6 Electrochemical sensor
    5.7 Flame ionization detector (FID)
    5.8 Flame temperature analyser (FTA)
    5.9 Photo ionization detector (PID)
    5.10 Paramagnetic oxygen detector
6 Operation of fixed gas detection systems
    6.1 General
    6.2 Installation
    6.3 Criteria for the placement of sensors and
          sampling points
    6.4 Operation
7 Operation of portable and transportable gas detection
    apparatus
    7.1 General
    7.2 Operation
8 Training
    8.1 Operator training
    8.2 Maintenance training
Annex A (informative) Physical and chemical principles
of sensors
A.1 - Catalytic sensors (see 5.2)
A.2 - Thermal conductivity sensors (see 5.3)
A.3 - Infrared absorption sensors (see 5.4)
A.4 - Semiconductor sensors (see 5.5)
A.5 - Electrochemical sensor (see 5.6)
A.6 - Flame ionization detectors (FID) (see 5.7)
A.7 - Flame temperature analyser (FTA) (see 5.8)
A.8 - Photo ionization detector (PID) (see 5.9)
A.0 - Paramagnetic oxygen detector (see 5.10)
Annex B (informative) Nature of a release
B.1 - General
B.2 - Parameters influencing the release
B.3 - Outdoor sites and open structures
B.4 - Buildings and enclosures
Annex C (informative) Measuring ranges up to LEL
C.1 - Reference to the annex of EN 50054
Annex D (informative) Environmental parameters
D.1 - Typical environmental conditions used in type testing

This document gives guidance on the selection, installation, use and maintenance of electrically operated Group II apparatus intended for use in industrial and commercial safety applications for the detection and measurement of: combustible gases, as described in EN 50054, EN 50057, EN 50058 or oxygen as described in EN 50104. This guide is a compilation of practical knowledge to assist the user. Combustible gas detection apparatus, fixed, transportable or portable, may be used whenever there is the possibility of a risk to life or property caused by the accumulation of a combustible gas-air mixture. Such apparatus can provide a means of reducing the risk by detecting the presence of the combustible gas and issuing suitable audible or visual warnings. It may also be used to initiate specific safety precautions (e.g. plant shutdown, evacuation, operation of fire extinguishing procedures). It is applicable to all new permanent installations and, where reasonably practicable, to existing permanent installations. It is also applicable to temporary installations, whether new or existing. This Guide is not intended, but may provide useful information, for the following apparatus intended for the measurement of oxygen deficiency which may affect human health, apparatus intended only for the detection of non-combustible toxic gases; apparatus of laboratory or scientific type intended only for analysis or measurement purposes; Apparatus intended for underground mining applications; apparatus intended only for process control applications; This Guide does not apply to the following: apparatus for the detection of explosives; apparatus intended for the detection of a potentially combustible atmosphere resulting from dust or mist in air; open path apparatus not used for point measurement