Composition: Specific Gravity Analyser (Relative Density)

Uncategorized > Composition: Specific Gravity Analyser (Relative Density)


Specific Gravity (SG) analysers are purpose-built gas monitors, which can determine the specific gravity or Relative Density of the flare gas.

How it Works

The gas sample pressure is measured by a pressure transmitter, this gas then flows through the density meter assembly which contains a vibrating element, a rotameter, and a flow control valve.  As the density of the gas around the element changes, the natural vibration frequency of the element changes too.

The measured pressure and the measured frequency of the vibrating element in the density meter allows the measured density and Specific Gravity of the gas to be determined.


Flare Gas Analysers incorporating Wobbe Index and Specific Gravity analysers are used widely in the Oil and Gas Industry.


  • On-line analysis at regular intervals

  • High accuracy

  • Low uncertainty


  • Maintenance requirements

  • Equipment costs

  • Maintenance costs

Case study

No case study available at this time.

On-line analysis

On-line analytical methods involve extracting a sample from a flare system via an automatic sampling system and analysing it continuously with a field installed analyser system.

Translate this page »