NOx Analyzer

NOX Analyzer

The OMA is the ideal multi-component instrument for analyzing true NOX (NO + NO2) in emissions and critical process applications.

The release of nitrogen oxides (NOX) to the atmosphere causes the formation of nitric acid rain and depletes the ozone layer. These emissions are heavily regulated around the world. Industrial combustion sites must report the amount of NOX exiting their stack and often implement processes like DeNOX to reduce these emissions.

  • Continuously measures true NOX concentration by monitoring NO and NO2 absorbance curves
  • Totally solid state build with no moving parts — modern design for low maintenance
  • Affordable alternative to large CEMS investments
  • Optional close-coupled installation provides faster response than extraction at less cost than cross-stack

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The release of nitrogen oxides (NOx) to the atmosphere causes the formation of nitric acid rain and depletes the ozone layer. These emissions are heavily regulated around the world. Industrial combustion sites must report the amount of NOx exiting their stack and often implement processes like DeNOx to reduce these emissions.

NOX Absorbance Spectra

To measure true NOX, the OMA individually measures NO and NO2 concentrations. The powerful multi-component software isolates the distinctive absorbance curves of the analytes and mathematically isolates their structures from the total sample absorbance. In accordance with Beer-Lambert Law, the OMA correlates the height of these curves directly to real-time concentrations. The NOX reading is a simple sum of the two measurements.

Absorbance Curves: NOX

Absorbance (AU)
Wavelength (nm)


All OMA models are equivalent in function and performance with identical electronic configurations. The models vary by form factor and materials of construction, each intended for a unique use case.



Wall-mounted process analyzer

  • Indoor/outdoor use
  • ATEX, Class I Div 1/2, GOST...
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Suitcase process analyzer

  • Carry from site to site
  • Rugged suitcase enclosure
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Rackmount process analyzer

  • Fits standard 19" rack
  • Ideal for lab/shelter
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Explosion-Proof Models

The OMA-300 is offered in two explosion-proof formats:

Exp (Purged) Explosion-Proof OMA-300


Eexp systems are purged and pressurized using a certified air-purging device. This method ensures that toxic/explosive gas is not allowed to accumulate inside the enclosure and is ideal when instrument air is available.

Exd (Cast Aluminum) Explosion-Proof OMA-300


Eexd systems are contained within certified explosion-proof cast-aluminum enclosures. This method is more practical if the installation is remote or utilities are unreliable.


The OMA is built for direct analysis of the hot/wet sample, thus simplifying the scope of the sample system and retaining high sample integrity. From our vast experience in sampling design, we know that applications can be similar but are rarely identical. For this reason, we design and build sample conditioning systems on a project basis, working from the process to the drawing board.


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 Dispersive ultraviolet-visible (UV-Vis) absorbance spectrophotometry
Detector nova II™ UV-Vis diode array spectrophotometer
Spectral Range 200-800 nm
Light Source Pulsed xenon lamp (average 5 year lifespan)
Signal Transmission 600 μm core 1.8 meter fiber optic cables
Other lengths available
Path Length Application-dependent
Sample Conditioning Custom design per application
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 and self-check diagnostic
Human Machine Interface Industrial controller with touch-screen LCD display running ECLIPSE™ Software
Data Storage 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 Standard: -20 to 70 °C (-4 to 158 °F)
Optional: up to 150 °C (302 °F) with cooling extensions
Contact AAI for temperatures above 150 °C (302°F)
Sample Pressure Using standard flow cell: 206 bar (3000 psi)
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;
Select analyzer type: OMA-300 Wall-Mounted Analyzer
OMA-206P Portable Analyzer
OMA-406R Rackmount Analyzer
NOX Accuracy
Example ranges below. Custom ranges available.
0-100 ppm ±5 ppm
0-10,000 ppm ±2% full scale or 5ppm*
0-100% ±2% full scale
*Whichever larger.
Standard Design General Purpose
Available Options ATEX, IECEx, EAC, PESO, JPN
Please inquire with your sales representative for additional certifications (CSA, FM etc.).


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