Instruments - FTIR

The IMx Monitoring System
The IMx Monitoring system is a highly modular Fourier Transform Infrared (FTIR) monitor (gas measurement equipment) that can be configured by the user to perform one of several different monitoring tasks. The IMx consists of a base unit and snap-on accessories. The accessories allow for a) extractive monitoring (e.g. stack or process control) using one of several different cell configurations, or b) open-path monitoring (e.g. cross-stack or open-air) using telescope-based accessories. Open-path FTIR system allows for efficient fence-line monitoring. All units are NEMA-enclosed for use outdoors or in explosive environments and configurations exist for internal or external computer control.

Principle of Operation
The IMx is based upon a Fourier Transform Infrared (FTIR) spectrometer. This spectrometer gathers a full infrared spectrum, from near-visible to the far-infrared. Embedded in this spectrum are the absorption signatures (fingerprints) of all molecular compounds present in the sample. Because each molecular specimen has a unique fingerprint, automated software can be used to analyze a spectrum, thus identifying all compounds present and their concentrations. The actual analysis is done by comparing observed fingerprints in the spectrum with calibrated reference spectra stored on the hard drive of the analysis computer from the gas measurement equipment. Matching of patterns indicates the compounds present while matching of pattern intensities determines the individual gas concentrations. Because different gases absorb infrared with different intensities, the detection limits vary, but most gases can be detected in the low ppb-range.

Gases that can be measured with the IMx
The calibrated reference library currently in the IMx system has more than 200 compounds. IMx can thereby act as an HF analyzer, CH4 analyzer, and CO2 analyzer.  Any of these compounds can be analyzed for at any time with our gas measurement equipment. The system library contains both organic and inorganic compounds and focuses on compounds of interest to industrial process control and environmental monitoring. New species can and are being added to the library all the time, as required for specific applications.

For further information, please use the website of IMACC shown below, or email Ralph Brewer, IMACC