The BTEX detector employs the emission band of an ultraviolet light-emitting diode at 260 nm as monochromatic light source and photodiodes for the deep UV-range as reference and signal detectors. Optical fibres are used for coupling the light to the absorption cell of 40 cm length as well as to the reference photodiode. The use of an integrated circuit log-ratio amplifier allows the direct determination of absorbance values according to Lambert-Beer’s law. Linear calibration curves over two orders of magnitude, between about 1 ppm and 100 ppm, were obtained for benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene. There is some variation of the sensitivity between the six species, which correlate with differences in the absorption spectra, with toluene, ethylbenzene, o-xylene and m-xylene showing close values between 150 μAU/ppm and 185 μAU/ppm, while benzene with 62 μAU/ppm has a somewhat lower and p-xylene with 235 μAU/ppm a somewhat higher sensitivity. The limits of detection were determined as approximately 1 ppm.
from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2jvUTX4
via IFTTT
Εγγραφή σε:
Σχόλια ανάρτησης (Atom)
Δημοφιλείς αναρτήσεις
-
from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2jCvX3K via IFTTT
-
Abstract Purpose of Review Our goal is to summarize the airway disease literature since September 11, 2001 (9/11), focusing on studies pub...
-
Treatment effectiveness holds considerable importance in the association between service quality and satisfaction in medical service studies...
-
Vol.25 No.2 from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1P7bHxT via IFTTT
-
Publication date: Available online 16 January 2017 Source: International Journal of Pediatric Otorhinolaryngology Author(s): Kaveh Karimn...
-
Understanding Head And Neck Cancers - The Southeast Sun ... The Southeast Sun (NAPSI)—According to the Centers for Disease Control an...
-
Abstract Background Henoch–Schönlein purpura is the most common vasculitis in children. Its long-term prognosis depends on renal involve...
-
Publication date: June 2017 Source: International Journal of Biological Macromolecules, Volume 99 Author(s): Oliviero Carugo The positio...
-
Publication date: 21 February 2017 Source: Cell Reports, Volume 18, Issue 8 Author(s): Arielle Glatman Zaretsky, Christoph Konradt, Fabien...
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου