The IMx Monitoring System
The IMx Monitoring system is a highly modular Fourier Transform Infrared (FTIR) monitor 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.
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 specie has a unique fingerprint, automated software can be used to analyze a spectrum 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. Matching of patterns identifies the compounds present while matching of pattern intensities determines the individual gas concentrations. Because different gases absorb infrared with different intensities, the detection limits very 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. Any of these can be analyzed for at any time. The 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.

Gases that can NOT be measured with the IMx
Only molecular species can be detected in the infrared. As a result, atomic species cannot be detected with FTIR. In addition, homonuclear diatomic species (e.g. Cl2, N2, O2, H2, etc.) have no infrared absorption bands and they cannot be detected either.

Typical Applications of FTIR monitoring

Industrial process control Industrial fence-line monitoring Public exposure monitoring

Stack monitoring Pond/area monitoring Urban air monitoring

Ambient Air Monitoring Cooling tower/flare monitoring Emergency response detection

Industries using IMx systems for process control, worker exposure monitoring, or environmental monitoring

Chemical plants Aircraft manufacturing Power Plants Incinerators

Petrochemical plants Steel furniture manufacturing Gas pumping stations Waste disposal facilities

Refineries Polymer production Kilns Medical facilities

Advantages of the IMx FTIR system

• Can monitor many compounds simultaneously: typically thirty to fifty are monitored simultaneously in real time
• Produces near-real time, continuous results: The IMx can collect and display results as fast as once per second although it is usually used in industrial facilities with averaging times on the order of one minute to several minutes.
• Can cover a broad range of concentrations: The IMx can detect from the low ppb-range to the high percent range. This allows it to be used in diverse applications requiring broad coverage yet high sensitivity.
• Can monitor long, multiple open-air paths: The IMx, in its open path mode, can cover paths up to 1 km in length. The unit also has accessories allowing multiple paths to be monitored with one FTIR base unit making it very cost effective.
• Rugged design applicable to industrial monitoring: The IMx uses a rugged piston and cylinder moving mirror assembly as well as dynamic alignment that automatically aligns the instrument thousands of times per second throughout all data collection. These make the IMx very rugged and highly immune to vibration/temperature swings that plague other FTIR systems.
• Cost effective modular design: The IMx modular design allows it to be converted from one mode of operation to another. This means the system has extended life as it is used for various applications. An added benefit is that this type of manufacturing is much less costly because all components are identical. This has brought the cost of the system down substantially compared to other units of comparable quality.