BS IEC 61831:1999

Introduction
1 General
    1.1 Scope
    1.2 Reference documents
    1.3 Preliminary remarks
    1.4 Further considerations
    1.5 Reliability
    1.6 Design
    1.7 Centralisation
    1.8 Local mounting
    1.9 Pre-assembled systems
2 Health and safety
    2.1 Introduction
    2.2 Prevention of explosions and fires
          2.2.1 Flammable gases and vapours
          2.2.2 Combustible dusts
          2.2.3 Flammable gases, vapours and combustible dusts
    2.3 Prevention of toxic hazards
    2.4 Plant safety
    2.5 Radiation hazards
    2.6 Safety facilities
    2.7 Manual shut-down facilities
    2.8 Noise
    2.9 Alarm indication
3 Housings
    3.1 Introduction
    3.2 Definitions
    3.3 Selection of housing
          3.3.1 Analyser case
          3.3.2 Analyser cabinet
          3.3.3 Analyser shelter
          3.3.4 Analyser house (AH)
    3.4 Area classification and toxic danger
          3.4.1 Electrical area classification
          3.4.2 Toxic danger
    3.5 Construction and mounting
          3.5.1 General
          3.5.2 Analyser housing
          3.5.3 Analyser house (AH)
    3.6 Analyser housing ventilation requirements
          3.6.1 General
          3.6.2 Analyser cases
          3.6.3 Analyser shelters
          3.6.4 Analyser cabinets and analyser houses
    3.7 Design for natural ventilation
          3.7.1 Ventilation requirements
          3.7.2 Heating requirements
    3.8 Design for forced ventilation
          3.8.1 Ventilation requirements
          3.8.2 Air intake system
          3.8.3 Fan requirements
          3.8.4 Air distribution requirements
          3.8.5 Heating requirement
    3.9 Analyser housing safety monitors and alarms
          3.9.1 General
          3.9.2 Ventilation failure
          3.9.3 Flammable gas or vapour detection
          3.9.4 Toxic gas detection
          3.9.5 Oxygen deficiency detection
          3.9.6 Fire detection and protection
          3.9.7 Purged equipment
          3.9.8 Alarms
4 Sampling systems
    4.1 Introduction
    4.2 Definitions
    4.3 General requirements
    4.4 Sample point location
    4.5 Fast circulating systems
    4.6 By-pass systems
    4.7 Sample recovery systems
    4.8 Special considerations
    4.9 Multi-stream systems
    4.10 Construction
          4.10.1 General
          4.10.2 Material selection
          4.10.3 Flushing facilities
          4.10.4 Blockage removal
          4.10.5 Heat tracing and insulation
          4.10.6 Minimising risks from leakage
          4.10.7 Location of equipment
          4.10.8 Instrumentation
          4.10.9 Identification
    4.11 Effluent disposal
          4.11.1 General
          4.11.2 Vapour
          4.11.3 Liquid
    4.12 Calibration facilities
    4.13 Automatic calibration
5 Analyser communications
    5.1 Introduction
    5.2 Signal transmission
    5.3 Safety
    5.4 Cables
    5.5 Linearisation
    5.6 Use of signal
    5.7 Alarms
    5.8 Verification/calibration
Annex A - Typical analyser process line sampling probe for
          line sizes NPS 2" and above
Annex B - Determination of sample probe lengths
Annex C - Sample system calculations
Annex D - Natural ventilation calculations
Annex E - Forced ventilation calculations
Annex F - Example of verification/calibration sequence of data
          to computer
Annex G - Analyser house with forced ventilation - Summary of
          recommended control shut-down actions for flammable
          hazard operation
Annex H - Analyser houses with forced ventilation - Ventilation
          failure and flammable gas detection trip logic
Annex I - Typical analyser system schematics
Annex J - Example schematic showing a typical wall penetration
          using a transit
Annex K - Bibliography

Applies to an on-line analyser system. It provides the necessary guidance for the system supplier and user to specify or design a complete analyser system from sample point in the process to the final output for display or control purposes.

This technical report provides the necessary guidance for system supplier and user to specify or design a complete analyser system from sample point in the process to the final output for display or control purpose.