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  • CVA-100 Wobbe Index Analyzer
CVA-100 Wobbe Index Analyzer

Wobbe Index Analyzer

From natural gas to flare stack, the CVA-100 is the ideal instrument for monitoring the heating value of hydrocarbon streams.

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Performance & Usage

  • Straightforward residual oxygen analysis
    Using sample conditioning furnace
  • Solid state TDL oxygen analysis
    No moving parts or consumables
  • Single unified interface
    All sensors read to the central HMI

Reliability & Safety

  • Unattended operation
    Stabilized by Auto-Zero; remote operation optional
  • Inherently safe design
    Sample gas never enters analyzer enclosure Learn more
  • Customizable alarms & outputs
    4-20 mA analog outputs; MODBUS; Hart... View technical specs


The Wobbe Index (WI) expresses the heating value (known as calorific value) of gases used as fuels, taking into account the proportionality of calorific value to the specific gravity, or the density ratio between the given fuel gas and air. More precisely, the specific gravity is proportional to flow velocity through a constant orifice size at a constant pressure, and thus proportional to gas calorific value.

The CVA-100 puts continuous Wobbe Index monitoring and control in the hands of fuel gas producers, distributors, or anyone requiring WI readings for process optimization.


Principle of Operation

The CVA-100 uses VCSEL tunable diode laser technology to measure the residual oxygen value of sample combustion.

VCSEL laser technology

Inherent Safety

The CVA-100 has an inherently safe design because the toxic sulfur-laden sample does not enter the analyzer enclosure. The sample circulates through the external flow cell, which receives the signal via fiber optic cables.

wobbe index analyzer safety


The primary purpose of the CVA-100 sample conditioning panel is to pyrolyze the sample (i.e. controlled combustion).

CVA-100 sample conditioning system
  • 36”x36”x12” NEMA 4X carbon steel enclosure
  • Industrial pyrolyzing furnace
  • Two mass flow controllers for sample gas and air supply
  • Optional density transmitter
  • Oxygen sensor
  • Backpressure regulator to control the pressure of the gas flow
  • Two air-actuated 3-way valves
  • Includes 15 µm particulate filter and coalescing filter
  • Fast loop flow meter


Note: All performance specifications are subject to the assumption that the sample conditioning system and unit installation are approved by Applied Analytics. For any other arrangement, please inquire directly with Sales.

Measurement Principle tunable diode laser spectroscopy
Light Source VCSEL
Path Length Application-dependent
Sample Conditioning Complete system utilizes mass flow controllers to continuously mix sample gas with oxygen at a precise fuel:air ratio and pass the resultant mixture through a furnace tube heated to 1100 °C; after combustion, the sample is routed to the flow cell for residual oxygen measurement.
Analyzer Calibration If possible, analyzer is factory calibrated with certified calibration fluids; no re-calibration required after initial calibration; measurement normalized by Auto Zero
Reading Verification Simple verification with samples
Human Machine Interface Industrial controller with touch-screen LCD display running ECLIPSE™ Software
Data Storage 16GB Solid State Drive
Analyzer Environment Indoor/Outdoor (no shelter required)
Ambient Temperature Standard: 0 to 35 °C (32 to 95 °F)
Optional: -20 to 55 °C (-4 to 131 °F)
To avoid radiational heating, use of a sunshade is recommended for systems installed in direct sunlight.
Sample Temperature Max: 1300 °C (32 to 95 °F)
Sample Pressure Max: 10 bar abs.
Electrical 85 to 264 VAC 47 to 63 Hz
Power Consumption 45 watts
Standard Outputs 1x galvanically isolated 4-20mA analog output per measured analyte(up to 3; additional available by upgrade)
2x digital outputs for fault and SCS control
Optional Outputs Modbus TCP/IP; RS-232; RS-485; Fieldbus; Profibus; HART;
Size Analyzer: 24" H x 20" W x 8" D (610 x 508 x 203 mm)
Weight Analyzer: 32 lbs. (15 kg)
Enclosure Standard: wall-mounted carbon steel NEMA 4 enclosure
Accuracy (Wobbe Index) 45-50 range: ±0.2%
Accuracy (CARI) 13-16 range: ±0.2%
Resolution < 0.02%
Linearity Better than 1%
Span Drift < 2% of measurement range
Zero Drift < 1% per year

The following certifications are available.

NEC Class I, Division 1, Groups C & D; AEx d IIB T3
CEC Class I, Division 1, Groups C & D; AEx d IIB T3
GOST GOST Russian Gosstandart Pattern Approval


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