GASEX PORTA - Portable Gas analysis systems.
Standalone Gas Analysis System

Transportable and standalone FTIR Gas analysis system ideal for on field measurements. Powerful module for gas analysis, based on our robust and approved "Rocket" FTIR with combined with a 5 meters optical path, low volume ( 0.2 Liter) multi-pass heated cell.

The ARCoptix Gasex modules is the ideal product for system integrators looking for a customized and intergrable system. The Gasex system contains essentially 4 components:

The corrosion resistant gas cell can be heated up to 190 °C, which ensures that the sample stays in gaseous phase (and avoid condensation) even with high concentrations of H2O or corrosive gases. Many gases can be measured simultaneously like CO2, H2O, CO, NH3,NO, NO2, N2O, SO2, CH4, HF, HCl, and VOC´s. Limits of detection are typically around 1ppm and absolute precision of measured concentration is around a few percent (depending also of the quality of the calibrations and measurement conditions).

  • Optimized Gas cell and FTIR Assembly
  • Rohdium Chemical resitance Coatings
  • Resolution of 2 cm-1 (1 or 0.5 cm-1 on demand)
  • MCT Detector with high detectivity TE-cooled MCT detector 5000-830 cm-1 (2-12μm)
  • 5m heated gas cell with small volume (0.2L)
  • Battery Powered up to 8 hours field operation (heated)
  • Relatively compact (compared to other products on the market)
  • USB connectivity and SDK available
  • Cost effective

    Below Some examples of Spectra Measured with the Gasex system at 0.5cm-1:












    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 fixed to a common swinging arm, which rotates to create an optical path difference (with respect to the beam splitter) in the two arms of the interferometer.
    This type of design is called a permanently aligned interferometer. This particular arrangement of the interfeormeter 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 Porta Specifications


    Permanentely aligned, maintenance free, hermetic

    Resolution [cm-1 ]

    2 cm-1, 1 cm-1 or 0.5 cm-1

    Spectral range [cm-1 ]

    830 - 5000

    Beam-splitter/ windows


    Wavenumber repetability

    Scan frequency 2 - 4 spectrum / second (resolution depended)
    Control laser

    solid-state laser @850nm


    MCT,Thermoelectrically cooled;
    D*=2.5e9 Jones

    Signal to Noise ratio (at 0.5cm-1). 1 min scan time



    Position independent


    Active suppression of Water and Carbon dioxide inside the interferometer housing
    A/D converter 24 bit
    Communication interface USB 2.0
    Radiation source Glo-bar stabilized at 1550 K



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

    Path lenghth [m ]

    5 (other path lengths on demand)

    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)
    Communication USB 2.0 (optionally Wifi)
    Operating temprature 0°C - 35°C
    Operatings System Windows 64 bits
    Power Autonomy 8 hours in heated regime

    Dimensions [mm]

    450 x 300 x 200
    Total weight [kg] 13
    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. Basic examples are available for the following languages:

    • C#
    • Labview
    • Matlab

    Free data library search & analysis software

    Toegether with the Gasex Prota product we provide also a data analysis software that permits to

    • Compare masurements with customized or existing libraries
    • Create a chemiometric model from a choosen set of calibrated gas spectra.
    • Monitor evolution of the concentration of different gases.
    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 190 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. Gas calibration can be performed directely by the end-user or (dependingof the dangerosity) can be performed by Arcoptix on demand.

    Non- Exclusive Distributor List for Spectrometers
    France, Germany
    Italy, UK
    South Korea
    Switzerland and
    Rest of the world
    Gasex Drawing
    : not yet vailable
    DOWNLOADPDF Description of Gasex Porta analyser
    DOWNLOADPDF Quick Starter Guide
    DOWNLOADPDF Drawing Gasex Gas analyser
    DOWNLOAD PDF Application Note CO2 in Water
    DOWNLOADPDF Application Note NH3 in Water
    DOWNLOADPDF Application Note Isotope Measurement
    DOWNLOADPDF Tutorial about Fourier Spectrometry