@article{Helsper1995,
  author    = {Helsper, Christoph},
  title     = {Probleme der Staubprobenahme bei der Filterpr{\"u}fung},
  series = {Filtrieren und Separieren (1995)},
  journal   = {Filtrieren und Separieren (1995)},
  isbn      = {0933-5927},
  pages     = {5 -- 13},
  year      = {1995},
  language  = {de}
}
@article{HelsperMoelterHaller1990,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Haller, P.},
  title     = {Representative Dilution of Aerosols by a Factor of 10,000},
  series = {Journal of Aerosol Science. 21 (1990), H. Suppl. 1},
  journal   = {Journal of Aerosol Science. 21 (1990), H. Suppl. 1},
  isbn      = {0021-8502},
  pages     = {637 -- 640},
  year      = {1990},
  language  = {en}
}
@article{HelsperFissan1981,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Response Characteristic of a Polytec HC-15 Optical Particle Counter},
  series = {Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Association for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Associa-tion for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Schmallenberg, 22.10.80 - 24.10.80},
  journal   = {Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Association for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Associa-tion for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Schmallenberg, 22.10.80 - 24.10.80},
  publisher = {Pergamon Pr.},
  address   = {Oxford},
  pages     = {287 -- 292},
  year      = {1981},
  language  = {en}
}
@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{HelsperFissan1982,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Techniken zur Kalibrierung von Staubmeßger{\"a}ten / Fißan, H. J.; Helsper, C.},
  series = {Schwebstoffe und St{\"a}ube : analyt. u. techn. Aspekte ; Kolloquium N{\"u}rnberg 1981},
  journal   = {Schwebstoffe und St{\"a}ube : analyt. u. techn. Aspekte ; Kolloquium N{\"u}rnberg 1981},
  publisher = {VDI-Verl.},
  address   = {D{\"u}sseldorf},
  isbn      = {3-18-090429-1},
  pages     = {59 -- 64},
  year      = {1982},
  language  = {de}
}
@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{HelsperFissanMugglietal.1983,
  author    = {Helsper, Christoph and Fißan, H. J. and Muggli, J. and Scheidweiler, A.},
  title     = {Verification of Ionization Chamber Theory},
  series = {Fire Technology. 19 (1983), H. 1},
  journal   = {Fire Technology. 19 (1983), H. 1},
  isbn      = {1572-8099},
  pages     = {14 -- 21},
  year      = {1983},
  language  = {en}
}
@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}
}