04/30122896 DC : DRAFT SEP 2004

FORWARD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and units
5 General principles
6 Gas measurement
   6.1 General
   6.2 Volume measurement
   6.3 Calorific value measurement
        6.3.1 Measurement techniques and sampling
        6.3.2 Direct measurement (calorimetry)
        6.3.3 Inferential measurement
        6.3.4 Correlation techniques
   6.4 Volume conversion
        6.4.1 General
        6.4.2 Density
        6.4.3 Pressure and temperature
        6.4.4 Compression factor
   6.5 Calibration
   6.6 Data storage and transmission
7 Energy determination
   7.1 Interfaces
   7.2 Methods of energy determination
        7.2.1 Direct determination pf energy
        7.2.2 Indirect determination of energy
8 Strategy and Procedures
   8.2 Strategies for energy determination
        8.2.1 Strategies for the single interfaces
   8.3 Plausibility checks
9 Assignment methods
   9.1 Fixed assignment
        9.1.1 Fixed assignment of a measured calorific value
        9.1.2 Fixed assignment of declared calorific value
   9.2 Variable assignment
        9.2.1 Input at two or more different stations with
              zero floating point
        9.2.2 Input at two or more different stations with
              commingled gas flows
   9.3 Determination of the representative calorific value
        9.3.1 Arithmetic average calorific value
        9.3.2 Quantity weighted average calorific value
        9.3.3 Quality tracking
10 Calculation of energy quantities
   10.1 General calculation equations for energy
   10.2 Calculation of averaged value
        10.2.1 Arithmetic average of the calorific value
        10.2.2 Weighted average of the calorific value
   10.3 Volume conversion and volume to mass conversion
   10.4 Energy determination on the basis of declared
        calorific value
11 Accuracy on calculated energy
   11.1 Accuracy
   11.2 Calculation of uncertainty
   11.3 Bias
12 Quality control and quality assurance
   12.1 General
   12.2 Check of the course of the measuring data
   12.3 Traceability
   12.4 Substitute values
Annex A (informative) Mainly used instruments for and energy
                      determination techniques
Annex B (informative) Different possible courses of the
                      calorific value
Annex C (informative) Volume conversion and volume to mass
                      conversion
Annex D (informative) Incremental energy determination
Annex E (informative) Practical example for volume conversion
                      and energy quantity calculation
Annex F (informative) Practical example for averaging the
                      calorific value due to different delivery
                      situations
Annex G (informative) Ways to Determining Substitute Values
Annex H (informative) Plausibility check graphical example
Annex I (Informative) Uncorrected data, bias correction and final
                      result graphical example
Annex J (informative) Single reservoir calorific value determination

ISO 15112