Graded Interference Filter Spectrometer

The release of volatile organic compounds from industrial processes can have negative impacts on the environment while also posing significant health and safety concerns. In the environment, many of these chemical are considered precursors to ground-level ozone, which is the primary component of smog. In addition, many volatile organic compounds are cancer-causing in humans while others pose dangerous explosion hazards. These chemicals are used or produced in a variety of industries including the chemical, automotive, and semiconductor industries. Although chemical recovery and waste treatment strategies are employed to reduce the emissions of the volatile organic compounds, there is a strong need for a low-cost, compact sensor that can quickly and reliably identify leaks in the facility process line. Infrared spectroscopy is an excellent method for the analysis of volatile organic compounds, however, infrared spectrometers are complex instruments which are too expensive and physically bulky for leak detection applications where low-cost, portability and maneuverability are critical. Advanced Fuel Research, Inc. proposes to develop a low-cost, very compact infrared spectrometer based on a novel graded interference filter in combination with an infrared microbolometer focal plane array detector. Phase I will fabricate the graded interference filter. A prototype spectrometer will then be assembled with the filter coupled to a microbolometer focal plane array. Gas-phase measurements will demonstrate the spectral accuracy and resolution of the instrument. Phase II will result in a complete infrared spectral sensor covering the mid- and long-wavelength infrared regions, including the analysis algorithms and light gathering optics for remote chemical sensing. In addition to applications as a remote volatile organic compound leak detector, the technology developed in this program will have applications in gas sensing in proess monitoring the control and continuous emissions monitoring.