Fourier Transform Infrared Trace Gas Analyser

A Fourier Transform Infrared (FTIR) Trace Gas Analyser is a high-sensitivity spectroscopic instrument designed to detect and quantify chemical compounds present at very low concentrations — from sub-parts-per-million (ppm) down to parts-per-billion (ppb) and parts-per-trillion (ppt) levels — in complex gas-phase matrices including ambient air, industrial stack emissions, exhaled breath, cleanroom atmospheres, and controlled environment monitoring applications. The combination of FTIR’s simultaneous broad-spectrum measurement capability with extended optical path length sample cells delivers trace-level multi-component gas analysis from a single measurement scan without consumable reagents or carrier gases.

The instrument architecture centers on a high-brightness infrared source — globar or quantum cascade laser array on advanced variants — coupled into a long-path gas absorption cell achieving effective optical path lengths of 5 to 200 meters through White cell or Herriott cell mirror configurations that fold the infrared beam across multiple internal reflections within a compact cell body of 0.5 to 5 liters internal volume. Each additional meter of optical path length increases the absorption signal of a target compound proportionally, with 100-meter path cells achieving detection limits approximately 100 times lower than equivalent 1-meter single-pass cells at the same detector sensitivity.

Mercury cadmium telluride (MCT) photodetectors — thermoelectrically cooled to -80°C or liquid nitrogen cooled to -196°C on highest-sensitivity configurations — provide detector noise levels 10 to 100 times below ambient-temperature DTGS detectors, enabling the low signal levels produced by trace concentrations of target gases at ppb and ppt levels to be resolved above the instrument noise floor.

Spectral resolution of 0.5 cm⁻¹ resolves individual rotational-vibrational absorption lines in the spectra of small gas molecules including H₂O, CO₂, CO, CH₄, N₂O, NH₃, HCl, HF, and SF₆, enabling species identification and quantification in multi-component mixtures through reference library spectral fitting without interference from overlapping absorption bands of co-present compounds.

In Pakistan, FTIR trace gas analysers are deployed at industrial emission monitoring stations, pharmaceutical cleanroom atmospheric monitoring programs, environmental research stations measuring greenhouse gas flux, cement and energy sector regulatory compliance monitoring, and defense research institutions detecting chemical warfare agent simulants at trace concentrations.

Tactical Supply Pakistan supplies FTIR trace gas analysers for industrial emission monitoring, environmental research, and defense analytical procurement across Pakistan.