S-G-03–Specifications for the approval of type of gas metering devices–Part 16

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


Part 16: Gas chromatographs

Table of contents


1.0 Scope

This part of the Specifications applies to online and laboratory gas chromatographs used to perform a compositional analysis of a gas sample to calculate the calorific value and relative density.

2.0 Unit requirements

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

3.0 Metrological requirements

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

  • 2.1 Rated operating conditions
  • 2.3 Maximum permissible errors

3.1 Maximum permissible errors

3.1.1 Calorific value

The error must not exceed a maximum permissible error (MPE) of ± 0.5%.

3.1.2 Relative density

The error must not exceed a MPE of ± 0.7%.

3.1.3 Nitrogen and carbon dioxide concentrations

Where a gas chromatograph is intended to measure concentrations of only nitrogen and carbon dioxide, the error must not exceed a MPE of ± 0.1 mole %.

3.2 Repeatability

The repeatability error must not exceed the applicable limits specified in Table 1 below. The applicable repeatability limit is based on the mole percent (mol %) of the individual gas component, as documented on the particular gas mixture's certificate of calibration.

Part 16, Table 1: Repeatability limits
Gas component (mol %) Repeatability limit (mol %)
0 to 1 0.03
Over 1 to 5 0.05
Over 5 to 25 0.15
Over 25 0.30

4.0 Technical requirements

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

  • 3.1 Design, composition and construction
  • 3.4 Case
  • 3.7 Indication
  • 3.8 Output
  • 3.9 Power sources
  • 3.10 Software
  • 3.12 Registration

4.1 Calculations

Unless otherwise specified by MC, the calorific value and relative density of the sample gas must be calculated using the relative concentrations of all components of the sample gas as established in accordance with GPA 2172 and GPA 2145 or ISO 6976.

5.0 Marking requirements

Note: 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
    • (l) Protocol/interface for digital input and/or output
  • 4.9 External power supply
  • 4.10 Software
  • 4.12 Inspection number
  • 4.13 Verification marks
  • 4.14 Operating information

According to the characteristics of the device, the subsection 4.3 of Part 1 may also apply.

5.1 Recognized standard

The recognized standard used for the calculation of the calorific value and density must be marked on the nameplate, or be capable of being displayed by the gas chromatograph.

6.0 Sealing requirements

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

  • 5.1 General
  • 5.2 Electronic gas metering devices

7.0 Administrative requirements

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

8.0 Performance test requirements

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

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