ARCoptix OEM FTIR Spectrometer Gas Analysis Module
Combination of our FTIR ROCKET module and a multi-pass gas cell

The ARCoptix FTIR spectrometer GASEX OEM module represents a highly efficient, rugged and fully integrated solution for gas spectroscopy in our product portfolio. Our OEM010 module is coupled to a low volume (0.2L) heated (up to 200C) gas cell, in which light experiences multiple reflections, resulting in an integrated optical path of 5m with more than 50% transmission. The cell's internal optics is rhodium and gold coated, making it extremely resistant against most chemicals including acid gases such as HF, HCl, HBr, and many other gases like CO,CO2, NO, NO2, NH3, SO2,NOx, CH4, VOC's,...
The GASEX OEM has been standardized to operate with a resolution of 0.5cm-1, which makes it compliant with the newest legal regulations for emission measurements. Featuring a USB 2.0 connection, the unit can also host an embedded single-board computer for standalone operation. Typical limit of detection (LoD) are below 1 ppm for most of the gases with 20s integration time.


  • Optimized Gas cell and FTIR Assembly
  • Compact and rugged
  • Resolution of 2 cm-1 down to 0.5 cm-1
  • MCT Detector with high detectivity TE-cooled MCT detector 5000-830 cm-1 (2-12μm)
  • 5m heated gas cell with small volume (0.2L)
  • USB connectivity and SDK available
  • Cost effective


Below some examples of Spectra Measured with the Gasex system 0.5 cm-1 resolution:



Optical design of the system
Interferometer coupled to a white cell

The Gasex system consist of an interferometer module including also the MCT detector and an IR light source and a Multi-reflection gas cell. The light is produced by a black body radiation module and modulated by a dual corner cube interferometer.The light is then coupled into the Gas cell (where the gas to be analysed is injected) where it is relfected back and forth 32 times. Finally the light focused on the MCT detector.

How does the interferometer work?
Permanentely aligned interferometer

The heart of the FT-Rocket is dual corner-cube (retro-reflector) interferometer. The two corner-cubes are solidary to a common swinging arm, which rotates to create an optical path difference in the two arms of the interferometer.
This type of design is called a permanently aligned interferometer, as the alignment of the system is known to be the most robust against vibrations and temperature drifts. It never has to be realigned.
The swinging arm of the interferometer rotates on wear-free flexure system, making this mechanical system extremely robust and durable.

Solid-state reference laser

For measuring the movement of the mirrors, a solid-state reference laser is coupled into the interferometer. Compared to classic HeNe lasers, the solid-state lasers that we use are more compact and have a much longer life-time. They have a very low temperature-induced wavelegnth drift and, when kept at constant temperature with a Peltier element, their wavelength can be stabilized to a few PPM, thus providing a very accurate and reproducible wavelength scale. This is crucial for ensuring a day-to-day and unit-to-unit consistency..

GASEX Specifications
Product code GASEX-OEM-060-4TE GASEX-OEM-085-4TE GASEX-OEM-120-4TE
Beamsplitter material CaF2 ZnSe
Spectral range [cm-1] 5'000-1'660 6'600-1'200 5'000-830
Spectral range [μ m] 2.0-6.0 1.5-8.5 2.0-12.0
D* [cm Hz1/2W-1] >1x10E11 >8x10E9 >4x10E9
Signal-to-noise ratio (0.5cm-1, 1 min scan) >55'000:1 >35'000:1 >35'000:1
Detector type MCT, 4 stages thermoelectrically cooled
Interferometer design Permanently aligned with dual retro-reflector

Resolution [cm-1 ]

8,4, 2, 1 or 0.5 cm-1
Wavenumber repetability <10ppm
Scan frequency >1.5 Hz @0.5cm-1
Internal reference laser Temperature-stabilized solid-state laser @850nm


Active suppression of Water and Carbon dioxide inside the interferometer housing
A/D converter 24 bit
Operating temperature 10C - 40C
Humidity 90 % (Not condensing)
Communication interface USB 2.0
Built-in light source SiC globar stabilized at 1550 K
Power requirement (FT-IR only) <35W @ 12VDC
Software interface Windows 7/10/11, Labview, .net compatible dll, API for controlling the instrument via our DLL



Multi-pass, permanently aligned, directly mateched to the FTIR

Path lenghth [m ]

5 or 0.2 (short cell)

Internal volume [Litres ]


Zero gas loss

> 3 dB (less than  50 %)

Operation temperature [C]

 -20  to 200 (not condensing)
Construction Aluminium with inert coating
Parabolic mirrors

Aluminum body  with rhodium protected gold   coating 

Heaters for stabilization at 180C 

Electric 400 W  peak power, consumption in steady state:  around 30W


PID (integrated or customizable)

Operation voltage of heaters

220 V, (customizable for other voltages)

Gas  connectors

6 mm Swagelock (customizable)


Dimensions [mm]

380 x 180 x 120 
Total weight [kg] 3.9
ARCoptix Digital Acquisition Acquisition system: AoDAQ

The AoDAQ is a multi-threading, cross-platform and versatile software that simultaneously takes care of:

  • (1) Handling communication with the FT-IR via USB
  • (2) Processing raw signals to deliver the spectrum
  • (3) Running a TCP ethernet server

The AoDAQ can be installed on all sorts of computers, from desktop machines to embedded, low-power single board computers. Thanks to the hosting of a TCP server, the instrument data and parameters can be accessed locally and/or remotely. All communication with the instrument eventually reduces to a set of TCP/IP commands that allow to quickly acquire data, adjust parameters, monitor the instrument status etc. using the programming environment of your choice.

Free GUI basic software

The FTIR Rocket is delivered with a free Windows XP, 2000 (32-bit) and Windows 7 & 8 (32 and 64 bits) compatible graphical user interface (GUI) program.

The free basic software package allows the user to:

  • Configure hardware measurement parameters (amplifier gain, averaging, ...).
  • Display real-time spectral measurement results.
  • Set reference spectra (white, dark) and choose among raw spectra, transmission or reflection mode.
  • Usual features such as save, open, zoom, rescale...
  • Some specific features related to Fourier transform spectrometry: choose among spectrum or interferogram averaging, apodization, look and save the interferograms, etc.
Free API & Examples

The FTIR Rocket is also delivered with a free API that allows you to control the spectrometer with custom code via our DLLs. Examples are available for the following languages:

  • C++
  • C#
  • Labview
  • Matlab
Advanced data processing & analysis software
In collaboration with Labcognition GmbH in Germany we also offer additional Panorama software packages:
Math Add-on module

contains a set of standard manipulation operations used in spectroscopy, like normalization, derivative, baseline correction, peak picking and more. In addition some special operations are available, like multiplicative scatter correction, thickness correction or standard normal variate correction and others.

Quantity Add-on module
is an expert in multivariate data analysis with quantitative methods like PLS and MLR. A convenient and intuitive wizard guides you through all steps of calibration model development. Complex statistical methods become very easy to use even for non-experienced users.
Search Add-on module
is an ideal add-on to archive your spectroscopic data and related information. It includes spectrum and full text search functionality on spectral libraries of various different library formats or directly on data in the file system.
IRAnalyze software package

is a highly sophisticated IR spectrum interpretation tool. Based on an IR spectrum, it provides you with automatic results for IR bands to functional group correlations and their characteristic frequencies. Furthermore, it is a comprehensive electronic dictionary to browse frequiencies for correlated IR bands.


Sampling System
The sampling system can be used for measuringconcentrations of pollutants in wet, corrosive gas streams. The sample gas can be measured without drying since the sample pump, heated filter and valve are located in a module that is heated to 180 ºC. From the sampling system the gases can be directed directly into the gas cell for analysis.
Gas Cleaning

In some application, gas nedds to be cleaned before entering the gas cell with a scrubber system. The scrubber can consist of filters to remove particles, or absorber to remove water or corrosive compounds. Please contact Arcoptix to find a suitable solution for your application.


The calibration processus is highly dependend of the application. The Gasex system is not standard a fully calibrated system. The Calibriation of the system (i.e. concentration of measured gases) requires to master chemiometrics and signal evalutation as well as a deep knowledge of the aimed application. The integration of the FTIR gas analyser is generally done by our customer that has a better understanding of the end-user applications. On request Arcoptix can support the customers with this tasks.

Non-exclusive Distributor list for spectrometers:
For OEM Business: contact Arcoptix directly. FTIR OEM Business

South Korea
Switzerland and
Rest of the world
Gasex Drawing

Gas Analyzer Dimension in mm: