@article{HelsperFissan1982,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Zur Reaktion von Rauchdetektoren auf Brandkenngr{\"o}ßen / Fißan, H. J.; Helsper, C.},
  series = {Tagungsbericht zum Internationalen Vortragsseminar {\"u}ber Probleme der automatischen Brandent-deckung / Institut f{\"u}r Elektrische Nachrichtentechnik. Technische Hochschule Aachen ; Fachgebiet Nachrichtentechnik. Universit{\"a}t Duisburg, Gesamthochschule . 8. Internationales Vortragsseminar "AUBE 82"},
  journal   = {Tagungsbericht zum Internationalen Vortragsseminar {\"u}ber Probleme der automatischen Brandent-deckung / Institut f{\"u}r Elektrische Nachrichtentechnik. Technische Hochschule Aachen ; Fachgebiet Nachrichtentechnik. Universit{\"a}t Duisburg, Gesamthochschule . 8. Internationales Vortragsseminar "AUBE 82"},
  address   = {Duisburg},
  pages     = {20 -- 37},
  year      = {1982},
  language  = {de}
}
@article{HelsperFissan1983,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Calibration of the Polytec HC-15 and HC-70 Optical Particle Counters / Fißan, H. J. ; Helsper, C.},
  series = {Aerosols in the mining and industrial work environments, Vol. 3. Instrumentation, Marple, Virgil A. ; Liu, Benjamin Y.},
  journal   = {Aerosols in the mining and industrial work environments, Vol. 3. Instrumentation, Marple, Virgil A. ; Liu, Benjamin Y.},
  publisher = {Ann Arbor Science},
  address   = {Ann Arbor, Mich.},
  pages     = {825 -- 829},
  year      = {1983},
  language  = {en}
}
@incollection{HelsperFissanFranzen1978,
  author    = {Helsper, Christoph and Fissan, H. J. and Franzen, H.},
  title     = {Particle Size Distributions of Combustion Aerosols},
  series = {Atmospheric Pollution 1978 : Proceedings of the 13th International Colloquium; 25-28 April 1978; Paris, France; Edited by Michel M. Benarie},
  booktitle = {Atmospheric Pollution 1978 : Proceedings of the 13th International Colloquium; 25-28 April 1978; Paris, France; Edited by Michel M. Benarie},
  editor    = {Benarie, Michel M.},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {0-444-41691-9},
  doi       = {10.1016/S0166-1116(08)71583-8},
  pages     = {263 -- 266},
  year      = {1978},
  abstract  = {It has been observed that carcinogenic polycyclic aromatic hydrocarbons (PAH) are present in the atmosphere. Combustion processes are considered the most important sources for PAH. Among these, the burning of coal produces the highest emission, but in cities with high traffic density and low meteorological exchange activities, vehicle emissions determine the immission situation, especially in narrow streets. For estimating the potential health effects caused by PAH, it is sufficient to characterize the emission of PAH with respect to their physical state, concentrations, and, as far as the particulate phase is concerned, size distribution. The size distribution is important for transport phenomena, inhalation, and deposition in the respiratory tract. These parameters mainly depend on the combustion system, on system operating conditions, on the exhaust system, and on exhaust cooling conditions. At exhaust-gas temperatures in the range of ambient air temperatures, almost the whole emission of PAH is made up of particulate matter.},
  language  = {en}
}
@incollection{HelsperDressler2012,
  author    = {Helsper, Christoph and Dressler, J{\"o}rg},
  title     = {Partikelmesstechnik},
  series = {Reinraumtechnik},
  volume    = {2012},
  booktitle = {Reinraumtechnik},
  editor    = {Gail, Lothar and Gommel, Udo and Hortig, Hans-Peter},
  edition   = {3},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {978-3-642-19435-1},
  doi       = {10.1007/978-3-642-19435-1_3},
  pages     = {69 -- 95},
  year      = {2012},
  abstract  = {Der Schutz von Produkten vor der Kontamination durch Partikel gilt als eine zentrale Aufgabe der Reinraumtechnik. Da es dabei um Kontaminationseffekte weit unterhalb der visuellen Wahrnehmbarkeit geht, braucht es leistungsf{\"a}hige Verfahren, um die Messgr{\"o}ße „Partikelkontamination" {\"u}ber den gesamten Bereich, den Anwender fordern, pr{\"a}zise zu bestimmen. Neben der Partikelh{\"a}ufigkeit ist dabei die Gr{\"o}ße der Partikel, die sowohl das Transportverhalten wie auch die m{\"o}gliche Wirkung auf das Produkt beeinflusst, von entscheidender Bedeutung. Ferner kann es f{\"u}r die Ermittlung von Kontaminationsquellen von Interesse sein, die Form und die chemische Natur der Partikel zu bestimmen (z. B. textile Fasern, Metallabrieb, fl{\"u}ssige Tr{\"o}pfchen). Die Partikelh{\"a}ufigkeit wird {\"u}blicherweise als Konzentration, d. h. bezogen auf das analysierte Gasvolumen angegeben. Bei den in reinen Technologien {\"u}blichen niedrigen Konzentrationen dient als H{\"a}ufigkeitsmaß die Partikelanzahlkonzentration, also die Partikelanzahl pro Volumeneinheit des Tr{\"a}germediums.},
  language  = {de}
}
@article{HelsperDreilingHalleretal.1986,
  author    = {Helsper, Christoph and Dreiling, V. and Haller, P. and Kaminski, U.},
  title     = {Intercomparison of Eleven Condensation Nucleus Counters / Dreiling, V. ; Haller, P. ; Helsper, C.; Kaminski, U. ; Plomp, A. ; Raes, F. ; Roth, C. ; Schier, J. ; Sch{\"u}rmann, G.},
  series = {Journal of Aerosol Science. 17 (1986), H. 3},
  journal   = {Journal of Aerosol Science. 17 (1986), H. 3},
  isbn      = {0021-8502},
  pages     = {565 -- 570},
  year      = {1986},
  language  = {en}
}
@book{HelsperBesslingKiocketal.1979,
  author    = {Helsper, Christoph and Beßling, Harro and Kiock, R. and Fißan, H. J.},
  title     = {Experimentelle Untersuchung der Partikelanzahlkonzentration im Windkanal f{\"u}r den Einsatz von laseranemometrischen Verfahren / Beßling, Harro; Kiock, R.; Helsper, C.; Fißan, H. J.},
  publisher = {DFVLR},
  address   = {K{\"o}ln},
  pages     = {48 S.},
  year      = {1979},
  language  = {de}
}
@article{HelsperBartzFissanetal.1985,
  author    = {Helsper, Christoph and Bartz, H. and Fißan, H. J. and Kousaka, Y. (u.a.)},
  title     = {Response Characteristics for Four Condensation Nucleus Counters to Particles in the 3 to 50 nm Diameter Range / Bartz, H. ; Fißan, H. J. ; Helsper, C.; Kousaka, Y. ; Okuyama, K. ; Keady, R. Fruin, S. ; McMurry, P. H.; Pui, D. Y. H. ; Stolzenburg, M. R.},
  series = {Journal of Aerosol Science. 16 (1985), H. 5},
  journal   = {Journal of Aerosol Science. 16 (1985), H. 5},
  isbn      = {0021-8502},
  pages     = {443 -- 456},
  year      = {1985},
  language  = {en}
}
@article{HelsperBartz1987,
  author    = {Helsper, Christoph and Bartz, H.},
  title     = {Theoretische Bestimmung des Abscheidegrades eines Filters bei verschiedenen Betriebszust{\"a}nden / Bartz, H. ; Helsper, C.},
  series = {Staub, Reinhaltung der Luft. 47 (1987)},
  journal   = {Staub, Reinhaltung der Luft. 47 (1987)},
  isbn      = {0039-0771},
  pages     = {112 -- 114},
  year      = {1987},
  language  = {de}
}
@article{Helsper1979,
  author    = {Helsper, Christoph},
  title     = {Evaluation of Particle Size Distributions by Means of Particle Counters / Fißan, H. J. ; Helsper, C.},
  series = {Proceedings of the First Workshop of Particulate Control : 16. - 17. March 1978, Kernforschung-sanlage J{\"u}lich GmbH / prepared by U.S. Environmental Protection Agency, Off. of Research and Development, Washington, D.C, 1979,},
  journal   = {Proceedings of the First Workshop of Particulate Control : 16. - 17. March 1978, Kernforschung-sanlage J{\"u}lich GmbH / prepared by U.S. Environmental Protection Agency, Off. of Research and Development, Washington, D.C, 1979,},
  publisher = {Zentralbibliothek d. Kernforschungsanlage J{\"u}lich [in Komm.]},
  address   = {J{\"u}lich},
  pages     = {495 S.: Ill., graph. Darst.},
  year      = {1979},
  language  = {en}
}
@book{Helsper1981,
  author    = {Helsper, Christoph},
  title     = {Bestimmung, Simulation und Korrektur des nichtidealen {\"U}bertragungsverhaltens klassifizierender Aerosolmeßverfahren},
  publisher = {Univ.-Gesamthochsch},
  address   = {Duisburg},
  pages     = {65 S.},
  year      = {1981},
  language  = {de}
}