EN ISO 6570:2004

Foreword
Introduction
1 Scope
2 Normative references
3 Principle
4 Apparatus requirements
  4.1 Measurement installation
  4.2 Check for correct installation operation
5 Sampling
  5.1 General
  5.2 Sampling conditions
  5.3 Sample line
  5.4 Direct sampling
  5.5 Indirect sampling
6 Procedure
  6.1 Determination of potential hydrocarbon liquid content
  6.2 Determination of water formation
7 Expression of results
  7.1 Method A - Manual weighing method
  7.2 Method B - Indirect automatic method
8 Uncertainty of measurement
  8.1 Achievable uncertainty
  8.2 Gas leakage
  8.3 Bath liquid
  8.4 Wet gas
  8.5 Condensate leakage
  8.6 Variations in bath temperature and pressure in the
      gas/liquid cyclone separator
  8.7 Premature condensation
9 Test report
Annex A (informative) Selection of measurement temperature
        and pressure
Annex B (informative) Examples of the line-up of the apparatus
Annex C (informative) Example of calibration of the differential
        pressure gauge for the indirect automatic method - Method B
Annex D (informative) Example of an indirect automatic
        measurement - Method B
Annex ZA (normative) Normative references to international publications
         with their relevant European publications

This International Standard describes the principles of, and general requirements for, two gravimetric methods forthe determination of the potential hydrocarbon liquid content of natural gas, or similar gas, at a given pressure andtemperature. Two methods are specified in this International Standard to determine the amount of condensate in asample gas:_ Method A: a manual weighing method;_ Method B: an indirect automatic weighing method based on the indication of the pressure difference caused bythe accumulation of condensate in a vertical tube.The manual weighing method is a reference method for the indirect automatic method (Method B). The indirectautomatic method (Method B) is suitable for semi-continuous control.NOTE Unless otherwise specified, gas volumes are in cubic metres at 273,15 K and 101,325 kPa.