Open Path - Fourier Transform Infrared (OP-FTIR)


The Open Path - Fourier Transform Infrared (OP-FTIR) spectrometer system provides real-time multi-gas measurement (qualification and quantification) of gases. The optical spectrum analyzers transmit electromagnetic energy on the near-visible range. The energy travels through the gas field, to one or more reflectors, and then the returning spectra is evaluated to determine what gasses were encountered along the way. The OP-FTIR provides Infrared analysis of a sample volume outside of the instrument. Infrared optical gas analysis is provided along an open linear pathway, like a fence line, and bounced off a reflector back to the instrument for analysis. The open-path means the gas field is exterior to the instrument (open to the environment) and is reflected off of one reflector, and back to the instrument for analysis. The open-path also means the detected quantities of materials detected are the total over the entire length of the beam and will not indicate location of the vapors in the beam path.

In the pilot-scale demonstration, two open path FTIR (OP-FTIR) spectrometers; one fixed path OP-FTIR monitor and one multi-path OP-FTIR monitor (autonomous scanning) are installed in AP-Tank Farm. This system is used to detect chemical vapor emissions from the operating Hanford AP farm with an emphasis on tank farm boundaries (fence line detection). The data will be available via wireless communications to TFMCS and SAFER Systems.The technical details of the OP-FTIR can be found here: