| Autor: |
Stelmaszczyk, Kamil, Karpierz-Marczewska, Ewelina, Mikhnev, Valeri, Cywinski, Grzegorz, Skotnicki, Thomas, Knap, Wojciech |
| Předmět: |
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| Zdroj: |
Applied Sciences (2076-3417); Feb2022, Vol. 12 Issue 3, p1629, 25p |
| Abstrakt: |
Featured Application: Fast (picoseconds scale) and sensitive (ppm-level) detection of impurities in gasoline employing terahertz time-domain spectroscopy systems (THz-TDS) for petrochem-ical production lines or quality assessment and control facilities. In this article, we present the possibility of using terahertz time-domain spectroscopy to detect trace, ppm-level (%wt.) concentrations of admixtures in 95-octane lead-free gasoline in straightforward time-of-flight (pulse-delay) measurements performed directly in the liquid. The method was tested on samples containing 75–0.0125% of isopropanol and 0.3–0.0250% of water. The detection limits for isopropanol and water content were determined to be 125 ppm and 250 ppm, respectively, approaching the limits of much more complicated and time-consuming methods (like spectroscopy of the vapor phase). The measured pulse delays were compared with theoretical calculations using the modified Gladstone-Dale mixing rule for the solutions. The comparison demonstrated good agreement for gasoline-alcohol mixtures and large discrepancies for gasoline-water mixtures, suggesting that gasoline-water mixtures cannot be considered idealized binary mixtures. Our results clearly show that the pulse time delay measurement by THz-TDS is a fast and sensitive method of gasoline contamination detection and, as such, can be easily integrated with industrial online real-time quality control applications. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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