DD ENV 14236:2002

Foreword
1 Scope
2 Normative references
3 Terms, definitions and symbols
    3.1 Terms and definitions
    3.2 Symbols
4 Normal operating conditions
    4.1 Flow range
    4.2 Maximum working pressure
    4.3 Temperature range
    4.4 Range of gases
         4.4.1 General
         4.4.2 Test gases
         4.4.3 Test gas properties
5 Metrological performance
    5.1 General
    5.2 Mode comparison
         5.2.1 General
         5.2.2 Requirements
         5.2.3 Test
    5.3 Permissible errors
         5.3.1 Requirements
         5.3.2 Test
    5.4 Gas - air relationship
         5.4.1 General
         5.4.2 Requirements
         5.4.3 Test
    5.5 Pressure absorption
         5.5.1 Requirements
         5.5.2 Test
    5.6 Metrological stability
         5.6.1 Requirements
         5.6.2 Test
    5.7 Immunity to contamination in gas stream
         5.7.1 Requirements
         5.7.2 Test
         5.7.3 Specification of contamination dust
    5.8 Installation effects
         5.8.1 Requirements
         5.8.2 Test
    5.9 Zero flow
         5.9.1 Requirements
         5.9.2 Test
    5.10 Reverse flow
         5.10.1 Requirements
         5.10.2 Test
    5.11 Low flow registration
         5.11.1 Requirement
         5.11.2 Test
    5.12 High flow registration
         5.12.1 Requirement
         5.12.2 Test
    5.13 Pulsed (unsteady) flow
         5.13.1 General
         5.13.2 Requirements
         5.13.3 Test
    5.14 Temperature sensitivity
         5.14.1 Requirements
         5.14.2 Test
6 Construction and materials
    6.1 General
    6.2 Robustness of meter case
         6.2.1 General
         6.2.2 Protection against penetration of dust and water
         6.2.3 Resistance to internal pressure
         6.2.4 External leak tightness
         6.2.5 Heat resistance
         6.2.6 Connections
         6.2.7 Resistance to vibration
         6.2.8 Resistance to impact
         6.2.9 Resistance to mishandling
    6.3 Corrosion protection
         6.3.1 General
         6.3.2 Protection against external corrosion for material
                which is not corrosion resistant
         6.3.3 Protection against external corrosion for corrosion
                resistant material
         6.3.4 Protection against internal corrosion for material
                which is not corrosion resistant
         6.3.5 Protection against internal corrosion for corrosion
                resistant material
    6.4 Casework decorative finish
         6.4.1 Scratch test
         6.4.2 Humidity
    6.5 Ageing of non-metallic casework
         6.5.1 Requirements
         6.5.2 Test
    6.6 Ageing of external surfaces of the meter, including index
         windows and adhesion of the index window
         6.6.1 Requirements
         6.6.2 Test
    6.7 Protection against solar radiation
         6.7.1 Requirements
         6.7.2 Test
    6.8 Resistance to external relative humidity
         6.8.1 Requirements
         6.8.2 Test
    6.9 Flame retardance of external surfaces
         6.9.1 Requirements
         6.9.2 Test
    6.10 Resistance to storage temperature range
         6.10.1 Requirement
         6.10.2 Test
    6.11 Resistance to the effects of toluene/iso-octane vapour
         6.11.1 Requirements
         6.11.2 Test
    6.12 Resistance to water vapour
         6.12.1 Requirements
         6.12.2 Test
    6.13 Ageing
         6.13.1 Requirements
         6.13.2 Test
7 Optional features
    7.1 Pressure measuring point
         7.1.1 Requirements
         7.1.2 Test
    7.2 Resistance to high ambient temperature
         7.2.1 Requirements
         7.2.2 Test
         7.2.3 Meter fitted with a thermal shut-off valve
    7.3 Meters with temperature conversion
    7.4 Ancillary devices
    7.5 Use in hazardous zones
8 Index
    8.1 Recording and storage
         8.1.1 Requirement
         8.1.2 Test
    8.2 Display
         8.2.1 Requirement
         8.2.2 Test
    8.3 Segmental display
         8.3.1 Requirements
         8.3.2 Test
    8.4 Non-volatile memory
         8.4.1 Requirements
         8.4.2 Test
9 Marking
    9.1 All meters
    9.2 Two-pipe meters
    9.3 Durability and legibility of marking
         9.3.1 Requirements
         9.3.2 Ultraviolet exposure test
         9.3.3 Indelibility test
10 Software
    10.1 Requirements
    10.2 Test
11 Communications
    11.1 General
    11.2 Character transmission
    11.3 Communications protocol
    11.4 Data
         11.4.1 General
         11.4.2 Data read-out mode
         11.4.3 Data identifiers
         11.4.4 Data set structure
    11.5 Test-mode
         11.5.1 General
         11.5.2 Test-mode commands
         11.5.3 Response of meter to test commands
    11.6 Optical port
    11.7 Galvanic port (optional)
    11.8 Diagnostics
         11.8.1 General
         11.8.2 Displayed flags
12 Battery
    12.1 General
    12.2 Voltage interruptions
         12.2.1 Requirements
         12.2.2 Test
    12.3 Minimum operating voltage
         12.3.1 Requirements
         12.3.2 Test
    12.4 Battery life
13 Immunity to electromagnetic disturbances
    13.1 General
    13.2 Electrostatic discharge
         13.2.1 Requirements
         13.2.2 Test
    13.3 Radio frequency electromagnetic field
         13.3.1 Requirements
         13.3.2 Test
    13.4 Electromagnetic induction (power frequency)
         13.4.1 Requirements
         13.4.2 Test
    13.5 Electromagnetic induction (pulsed field)
         13.5.1 Requirements
         13.5.2 Test
    13.6 Radio interference suppression
         13.6.1 Requirements
         13.6.2 Test
14 Ultrasonic (acoustic) noise interference
    14.1 Requirements
    14.2 Test
         14.2.1 Test sequence
         14.2.2 White noise test
         14.2.3 Scanning frequency test
15 Meters supplied for testing
Annex A (normative) Production requirements for gas meters
A.1 Specification
A.2 Technical requirements
A.3 Certificates of conformity
Annex B (normative) Meters with gas temperature conversion
        devices
B.1 Scope
B.2 Metrological performance
      B.2.1 Errors of indication
      Gas and ambient temperature
      Gas and ambient temperature
      B.2.2 Gas air relationships
      Gas and ambient temperature
      Gas and ambient temperature
      B.2.3 Temperature sensitivity
Bibliography

Describes requirements and tests for the construction, performance and safety of battery powered ultrasonic gas meters (hereinafter referred to as meters), having co-axial single pipe, or two pipe connections, used to measure volumes of distributed fuel gases of the first and/or second and/or third family, as given in EN 437, at maximum working pressures of up to 0,5 bar and maximum actual flow rates of up to 10 m[3]/h over a minimum ambient and gas temperature range of -10 degree C to +40 degree C, for domestic applications. It also applies to meters where the measuring element and the register(s) are enclosed in the same case.