The article presents the detection of gases using an infrared imaging Fourier-transform spectrometer (IFTS). The Telops company has developed the IFTS instrument HyperCam, which is offered as a short- or long-wave infrared device. The principle of HyperCam operation and methodology of gas detection has been shown in the paper, as well as theoretical evaluation of gas detection possibility. Calculations of the optical path between the IFTS device, cloud of gases and background have been also discussed. The variation of a signal reaching the IFTS caused by the presence of a gas has been calculated and compared with the reference signal obtained without the presence of a gas in IFTS's field of view. Verification of the theoretical result has been made by laboratory measurements. Some results of the detection of various types of gases has been also included in the paper.
Concentrations and elemental composition of fine (PM2.5) and coarse (PM2.5-10) ambient particles, at two sampling points located at the same urban background sites, were investigated. The points were 20 m distant from each other and at various heights (2 and 6 m) above the ground. A dichotomous sampler, equipped with a virtual impactor, and a cascade impactor were used to sample the dust. An X-ray fluorescence spectrometer was used in the elemental analyses. The investigations revealed heterogeneity of the spatial distribution and the elemental composition of suspended dust at the investigated urban background site. Coarse dust, whose concentration at 2.0 m above the ground was affected by secondary emission from roads, soil and other local low-level sources in some periods, appeared more heterogeneous.