ABSTRACT
HNS quantitative spectral analysis can not be achieved with the existing infrared Fourier transform spectrometer. As a common monomer explosive concerned, quick identification and quantitative analysis of the substance is important, so it is necessary to research and design a HNS detection system based on THz spectroscopy. Transmissive mode was used in the system to calculate the content of HNS. Electro-optic modulator module was introduced in the system, in order to achieve steady and rapid static scanning optical path. In the experiments HNS characteristic absorption peak positions were acquired. With this basis, combined air absorption characteristics of the wavelength band and spectrum data correlation expression was obtained, thus more characteristic wavelengths selected were determined. According to Beer-Lambert law, the function expression of HNS content and coefficient formula were presented. In the experiment different content of HNS sample powder was obtained with chemical configuration method with the content at the standard level. It made HNS sample powder into HNS Sample slice for all HNS samples, and it carried out HNS content testing with MINI-Z Terahertz spectroscopy and the system. Experimental results show that the results of the two methods are similar in the range of 0.10% to 50.00% for HNS content. Their error is less than 5.0% compared to the standard value, and the system has better linearity.
ABSTRACT
In order to realize the indoor micro noxious gas real-time monitor, and enhance measuring accuracy based on the characteristic spectrum examination method, a characteristic wavelengths filtration window was designed, in which the container is full with the highly concentrated testing gas. The container with the highly concentrated testing gas was used as the filtration window, the standard air as the reference window, the air chamber sufficient testing gas for testing density. The experiment demonstrated that using the WQF-520-FTIR infrared spectroscope to obtain the infrared absorption spectrum of dipropyl sebacate, there were mainly four characteristic wavelength lines: 3.385 26, 3.417.64, 5.797 11, and 8.561 65 microm, and the corresponding extinction was 1.520 0, 1.542 1, 2.431 8 and 1.352 6 respectively. The smallest content examined was 50 ppb, but using the characteristic wavelengths filtration window, the method could realize the 10(-4) nm magnitude alignment. The sensitivity was enhanced nearly 10 times, and the characteristic wavelengths filtration window method has the merits of high sensitivity, no discontinuity, real-time examination, and so on.