Fourier Transform Infrared (FTIR) analysis is a technique of measuring chemical species (analytes) using selective and consistent absorption of infrared energy, specifically in the mid-infrared region [400 to 4,500 wave numbers, (cm-1)]. The infrared absorption characteristics of a specific compound are the "fingerprint" of that compound. The quantity of infrared light absorbed by a gas sample is proportional to the concentration.

Extractive FTIR refers to systems that remove gas from the stack or duct of interest, filter particulate matter and transport the gas through a heated sample line to an onsite mobile lab for continuous or semi-continuous "real time" analysis by an FTIR spectrometer.

The use of Fourier Transform Infrared (FTIR) monitoring systems continues to grow in the industrial and regulatory communities as more process applications are identified. Over the past 20 years, refinements in FTIR hardware and operating software have improved reliability and operability of the instrumentation to a level suitable for routine use. Further, as FTIR continues to prove itself (as demonstrated in Method 301 and 320 validations), it has become more accepted by regulatory agencies and more requested by industry. Indeed, the USEPA Emission Measurement Center (EMC) has acknowledged that FTIR technology shows promise since it has the capability to measure more than 100 of the 189 Hazardous Air Pollutants (HAPs) listed in Title III of the Clean Air Act Amendments (CAAA) of 1990. Upon passage of the CAAA, measurement methods existed for only 40 of the HAPs.

Applications
FTIR Monitoring can be applied to either process evaluations or environmental emissions measurements. Field applications using the FTIR system include:

Process

• Control Equipment Efficiency Testing
• Process Trial Studies
• Process Optimization

Environmental and Stationary Source Measurement

• Compliance Emissions Assessment to Meet Permit Requirements / Emission Standards
• Emissions Factor Development
• Compliance Assurance Monitoring (CAM)
• Source Screening
• Substitute to the Traditional Continuous Emissions Monitoring System (CEMS)

Advantages
The greatest advantage FTIR analysis has over traditional monitoring system analyzers is the capability of real-time measurements of multiple compounds simultaneously in very complex gas streams. This provides cost savings. It enables a system to be designed with fewer analyzers and substantially lowering total system cost per analyte.

There are several other advantages associated with the use of an extractive FTIR monitoring system:

• Data is acquired on a real-time basis. This is particularly suited to optimization studies, initial process trials, and design studies where the impact of a process adjustment or component modification can be evaluated nearly immediately.
• FTIR provides a distinct cost advantage when replacing numerous (traditional) analyzers like CO, NOx, SO2, and CO2, NH3, and HCl.
• Any gas that absorbs infrared light can potentially be identified and quantified using the FTIR. The technique has undergone USEPA validation for about 40 HAPs.
• The interferogram is a permanent record of the testing conducted. It can be analyzed in the future to identify and quantity additional IR-absorbing gas compounds not known or selected for analysis at the time of sampling.
• Source-specific test methods containing reference spectra of the gas compounds of interest are required to obtain accurate, representative data. Once a test method is developed for a specific source or a number of similar sources, it can be used over again, reducing mobilization and overhead costs.
• The FTIR, once set for an application, is less labor intensive than traditional test methods.
• The FTIR is totally automated, allowing for around-the-clock data collection without operator assistance.
• The FTIR is self-calibrating once quality reference spectra have been generated.
• The FTIR is capable of monitoring over large concentration ranges without re-calibration.

• A versatile measurement tool
• Reliable and accurate
• Capable of measuring complex gas streams
• Capable of achieving low detection limits
• Cost effective and easy to use.

Avogadro testing capabilities now include extractive Fourier Transform Infrared (FTIR) monitoring. FTIR monitoring can be applied to both process evaluations and environmental emissions measurements. This makes us uniquely qualified to provide these very specialized services to meet your needs.