S-G-03–Specifications for the approval of type of gas metering devices–Part 11

Category: Gas
Issue date:
Effective date:
Revision number: 3
Supersedes: S-G-03 (rev. 2)


Part 11: Electronic gas metering devices incorporating volume conversion functions

Table of contents


1.0 Scope

This part of the Specifications applies to electronic devices incorporating volume conversion functions. Such devices include:

  • flow computers;
  • electronic volume conversion (EVC) devices;
  • gas meters incorporating EVC functions.

Four types of volume conversion functions are covered in this part :

  • temperature only;
  • pressure only (with or without a fixed pressure multiplier capability);
  • pressure and temperature;
  • pressure, temperature and compressibility.

2.0 Unit requirements

Note: The requirements of Part 1, section 1.0 apply.

3.0 Metrological requirements

Notes: The following requirements of Part 1, section 2.0 apply:

  • 2.1 Rated operating conditions
  • 2.3 Maximum permissible errors
  • 2.16 Supply voltage variation

According to the characteristics of the device, the following requirements may also apply:

  • 2.6 Working pressure
  • 2.7 Temperature

3.1 Maximum permissible errors

3.1.1 General

The difference between the error of the converted registration and the unconverted registration must not exceed the MPE specified in Table 1 below.

Part 11, Table 1: Maximum permissible errors for electronic devices incorporating volume conversion functions
Volume conversion as a function of the: Test conditions MPE for devices without sensors MPE for devices with sensors
Pressure or temperature Reference ± 0.2% ± 0.5%
"Other than reference" As specified in subsection 3.2.2 ± 1.0%
Pressure and temperature Reference ± 0.2% ± 0.8%
"Other than reference" As specified in subsection 3.2.2 ± 1.3%
Pressure, temperature and
compressibility
Reference ± 0.3% ± 1.0%
"Other than reference" As specified in subsection 3.2.2 ± 1.5%
3.1.2 Devices without sensors

For devices (e.g. flow computers) without sensors, the difference between the error established at reference test conditions and the error at "other than reference" test conditions must not exceed ± 0.2%.

4.0 Technical requirements

Notes: The following requirements of Part 1, section 3.0 apply:

  • 3.1 Design, composition and construction
  • 3.4 Case
  • 3.6 Flow direction
  • 3.7 Indication
  • 3.9 Power sources
  • 3.10 Software
  • 3.12 Registration

According to the device characteristics, the following requirements may also apply:

  • 3.2 Minimum temperature range
  • 3.3 Automatic volume conversion
  • 3.8 Output
  • 3.11 Compressibility factor

4.1 Frequency of sampling

The device must be capable of sampling applicable inputs and calculating the measurement quantities at least every 30 seconds. Where no input is received from the primary meter, no sampling need take place.

4.2 Calculations

4.2.1 General

Calculations of measured quantity must be according to appropriate flow equations and other provisions of the Electricity and Gas Inspection Act and Electricity and Gas Inspection Regulations.

4.2.2 Flow computers

The following requirements apply:

  • Calculations by flow computers intended for use with orifice meters must minimally be according to the provisions of the latest version of AGA Report No. 3.
  • Calculations by flow computers intended for use with cone-shaped differential pressure meters must minimally be according to the provisions of the Appendix A.
  • Calculations by flow computers intended for use with conditioning orifice plate meters must minimally be according to the provisions of the Appendix B.

4.3 Non-measured data

The non-measured data necessary for conversions and correction must be present in the device (e.g. flow computer) before a measurement is made.

4.4 Multi-channel flow computers

The following requirements apply:

  • Where a flow computer is designed to process information from more than one meter, it must be capable of accepting the required meter-specific inputs separately for each meter.
  • The inputs for base pressure, base temperature, atmospheric pressure, relative density and mole percent content of the gas components applicable to the calculation method applied or calorific value may be common for all meters, subject to the following requirements:
    • Common inputs for relative density and mole percent content of the gas components applicable to the calculation method applied or calorific value must be limited to use with groups which are fed from a common supply of gas; and
    • Common inputs for atmospheric pressure must be limited to use with groups of gas meters in order to comply with the requirements of the Electricity and Gas Inspection Regulations.

4.5 Associated measurement information

The following information must be accessible via the display, or through provisions for printing this information or other method:

  • Values of all fixed constants or quantities used in the calculation of measured quantity;
  • Values of all live quantities used in the calculation of measured quantity.

5.0 Marking requirements

Notes: The following requirements of Part 1, section 4.0 apply:

  • 4.1 Permanency and legibility
  • 4.2
    • (a) Departmental approval number
    • (b) Manufacturer's name or registered trademark
    • (c) Model or type designation
    • (d) Serial number
    • (e) Ambient temperature range, where less than -30 °C to 40 °C
    • (f) Pmin (where applicable) and Pmax
    • (j) Gas temperature range for which the errors ≤ MPE
  • 4.10 Software
  • 4.12 Inspection number
  • 4.13 Verification marks

According to the characteristics of the device, the following requirements may also apply:

  • 4.3 Bar codes or quick response codes
  • 4.4 Temperature converted volume
  • 4.5 Pressure converted volume
  • 4.7 (b) Bidirectional flow measurement
  • 4.9 External power supply
  • 4.14 Operating information
  • 4.16 Modular design

5.1 General

The following information must be marked on the nameplate or made accessible through a display, printer or interrogation software or other means:

  • Minimum and maximum ranges of measurement parameters for all sources which the device may be configured to;

    Note: Minimum ranges are not required where the configuration application does not permit a configuration below the minimum range.

  • Configured range of measurement parameters for all sources which the device is configured to measure;
  • Value of each of the variables in the equation used to determine measured quantity.

5.2 Use of codes

Where codes are used, a legend must appear on the device.

6.0 Sealing requirements

Note: The requirements of Part 1, section 5.0 apply.

7.0 Administrative requirements

Note: The requirements of Part 1, section 6.0 apply.

7.1 Fixed constant

Where switch settings, jumper locations or other means used to identify the value of a fixed constant is permitted in the notice of approval, the approval must identify each fixed constant for which the method is applicable and the configuration or the other means for each value of each fixed constant.

8.0 Performance test requirements

Note: Test conditions and performance tests can be obtained by contacting MC.

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