Fourier Transform Infrared Gas Analyzer

A Fourier Transform Infrared (FTIR) Gas Analyzer is a spectroscopic instrument that simultaneously identifies and quantifies multiple gas-phase chemical compounds within a sample stream by measuring their characteristic infrared absorption signatures across a broad wavenumber range in a single measurement scan. Unlike single-gas electrochemical or NDIR sensors that detect one or two target compounds, FTIR gas analyzers resolve complex multi-component gas mixtures — including simultaneous measurement of 20 or more compounds — from a single measurement, making them the preferred analytical tool for stack emission monitoring, process gas analysis, atmospheric research, and industrial hygiene applications requiring comprehensive gas-phase chemical characterization.

The instrument’s Michelson interferometer generates an infrared beam modulated across the full mid-infrared spectral range — typically 600 to 4,000 cm⁻¹ — that passes through a temperature-controlled multi-pass gas cell with an optical path length of 0.2 to 20 meters. Extended path lengths are achieved through White cell or Herriott cell mirror configurations that fold the beam across multiple passes within a compact cell body, increasing effective absorption path length and detection sensitivity without requiring a physically long sample cell. Mercury cadmium telluride (MCT) detectors — thermoelectrically cooled or liquid nitrogen cooled — provide the sensitivity required for trace-level gas detection at concentrations from sub-parts-per-million to percent levels.

Quantitative analysis uses classical least squares (CLS) or partial least squares (PLS) spectral fitting algorithms to deconvolute overlapping absorption bands from multiple compounds in a mixture, comparing measured spectra against reference spectra libraries containing thousands of pure gas compound spectra acquired at matched temperature and pressure conditions. Measurement update rates of 1 to 30 seconds per complete spectral scan enable near real-time process monitoring and emission reporting.

Heated sample lines — typically maintained at 180°C to 200°C — transport stack gas samples to the analyzer cell without condensation of moisture, acid gases, or semi-volatile compounds that would compromise measurement accuracy and corrode sample handling components.

In Pakistan, FTIR gas analyzers are deployed at industrial stack emission monitoring installations, cement and brick kiln emission compliance programs, petrochemical facility process gas analysis stations, pharmaceutical manufacturing solvent vapor monitoring, and environmental research programs measuring atmospheric trace gas compositions.

Tactical Supply Pakistan supplies FTIR gas analyzers for industrial emission monitoring, process analysis, and environmental measurement procurement across Pakistan.