ABB Open Path 开路傅里叶红外 FTIR.pdf

? ABB Group March 29, 2015 | Slide 1 Open-path FTIR ABB Measurement Products – Analytical Solutions OP-MR configuration § Mono-static configurationAnalyze the air filling the optical path between the instrument and a retroreflector. The spectrometer acts as a light modulator, sending the light to the remote retroreflector (via a 25 cm diameter telescope) and senses the returned beam from the retroreflector with a photovoltaic MCT detector. The retroreflectoris composed of an array of cubes-corners. In this mode of operation, the optical path is twice the distance between the instrument and the retroreflector. ? ABB Group March 29, 2015 | Slide 2 OP-MR configuration § Passive configurationMeasure the infrared energy emitted by the sample. The spectrometer collects the sample emitted energy via its 25 cm diameter telescope which is then collimated into the Michelson interferometer to be modulated and finally sent to the detector module. In passive configuration the OP-MR uses the MR series FTSW500 radiometric software to control the instrument, collect the data and perform the radi-ometric calibration. ? ABB Group March 29, 2015 | Slide 3 Mono-static to passive configuration § The opto-mechanical interface of the OP-MR is design to be easily converted from one configuration to the other (Mono-static – passive). Changing configuration is essentially replacing the source and detector module which consist of an indexed threaded mechanical fix without needs of alignment. ? ABB Group March 29, 2015 | Slide 4 ABB Open-path FTIR The instrument is configured for monostatic monitoring; which consist in generating an infrared signal from the interferometer,send this signal to the retro-reflector to be reflected back to the FTIR and collected by a MCT detector. The air path between the FTIR and retro- reflector is absorbing part of the infrared signal and provides the atmospheric transmission signature. ? ABB Group March 29, 2015 | Slide 5 Open-path FTIR系统构成 ? ABB Group March 2