Fuel gas & flare gas combustion measuring

The WIM COMPAS™ adds to Hobré’s portfolio of process analyzers for (Fuel and flare gas combustion measuring) measuring the Wobbe Index, heating value (BTU) and the Combustion Air Requirement Index (CARI). Designed and manufactured in-house, the WIM COMPAS™  builds on hobré’s 20+ years of success and experience with residual oxygen type analyzers. The WIM COMPAS™  is used to control the thermal input and air:fuel ratio in such a way that disturbances caused by fuel gas quality fluctuations are minimized, the combustion process occurs with maximum efficiency and emissions are reduced to a minimum.

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Key benefits

  • Can be installed outdoors
  • Easy to operate
  • Unmatched response time
  • Suitable for installation in hazardous area
  • Safe flameless design
  • Handles high dewpoint
  • Measures flare gases and sour gases
  • Zero Hydrocarbon Emission

We are the world leader and manufacturer for BTU* Analyzers on flares

*) BTU = British Thermal Unit




“The WIM COMPAS ™ after our flare recovery system is the best way to control we don’t emit any unburned hydrocarbons and monitor compliance at the lowest costs”


WIM COMPAS ™– Versions



This version is designed for top performance where response time, repeatability and reliability count. A small sample flow is mixed continuously with air. The air-fuel mixture undergoes catalytic combustion followed by measurement of the residual oxygen. This provides a direct measure of CARI and correlates to the Wobbe Index as per ASTM 4891-89. By integrating a specific gravity cell, heating value and air demand are also measurable.

Infographic 1. Continuous configuration

Cyclic injection

Infographic 2. Injection configuration

The WIM COMPAS™ offers an unmatched, robust solution with high availability, for Fuel and flare gas combustion measuring, such as sour gas and flare gas. Hobré has developed an analyzer especially for these kinds of applications, that injects small amounts of gas into an air stream, typically at intervals of 30 seconds. The oxygen peak size is a direct measure of the air demand and proportional to the heating value (BTU).



Keeping the gas above dewpoint is crucial to the success of most applications. The WIM Compas™ can be heated up to 55°C (131°F) as standard; high-temperature versions (up to 150°C / 300°F) are available if required



Product Comparison

In the table below, you may find the differences of the WIM variants available:

TechnologyResidual Oxygen methodResidual Oxygen methodResidual Oxygen methodResidual Oxygen method
PrincipleContinuous typeContinuous typeInjection typeInjection HT
Typical ResponseT90 <5 secondsT90 <5 secondsUpdate time 30 secondsUpdate time 30 seconds
Gas / ApplicationNatural Gas, LNG – Blending, Turbine (Power)Fuel gas – Blending, Turbine (Power), Burner/Furnace/Heater/BoilerBlast Furnace Gas, Coke Oven Gas, Flare gas, Sour gas –
Steel applications, Flaring
Flare gas, Sour gas (high dew point up to 150°C/300°F) – Flaring



International Standards and Conformity Assessment for all electrical, electronic and related technologies  

We are committed to quality and we would like to share this commitment with you.

Immediately we offer a total guarantee for a maximum of 10 years after delivery on the WIM COMPAS.


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