TY - JOUR A1 - Helsper, Christoph A1 - Wiedensohler, A. A1 - Weise, W. A1 - Lütkemeier, E. T1 - Determination of the Bipolar Charge Equilibrium in Pure Gases / Wiedensohler, A. ; Weise, W. ; Helsper, C. ; Lütkemeier, E. JF - Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft für Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR) Y1 - 1986 N1 - International Aerosol Conference ; (2, 1986, Berlin (West)) SP - 383 EP - 386 PB - Pergamon Press CY - Oxford [u.a.] ER - TY - JOUR A1 - Helsper, Christoph A1 - Fißan, H. J. A1 - Thielen, H. J. T1 - Determination of Particle Size Distributions by Means of an Electrostatic Classifier / Fißan, H. J.; Helsper, C. ; Thielen, H. J. JF - Journal of Aerosol Science. 14 (1983), H. 3 Y1 - 1983 SN - 0021-8502 SP - 354 EP - 357 ER - TY - JOUR A1 - Helsper, Christoph A1 - Fißan, H. J. A1 - Kapadi, A. A1 - Liu, B. Y. H. T1 - Data Inversion by Simplex Minimization for the Electrical Aerosol Analyzer JF - Aerosol Science and Technology. 1 (1982), H. 1982 Y1 - 1982 SN - 0278-6826 SP - 136 EP - 146 ER - TY - JOUR A1 - Helsper, Christoph A1 - Lütkemeier, E. A1 - Wiedensohler, A. T1 - Charge Distribution by Unipolar Charging of Small Aerosol Particles / Lütkemeier, E. ; Helsper, C. ; Wiedensohler, A. JF - Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft für Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR) Y1 - 1986 N1 - International Aerosol Conference ; (2, 1986, Berlin (West)) SP - 474 EP - 478 PB - Pergamon Press CY - Oxford [u.a.] ER - TY - JOUR A1 - Helsper, Christoph A1 - Mölter, W. T1 - Characteristics of a Nebulizer with Cyclone Preseparator / Mölter, W. ; Helsper, C. JF - Aerosols, their generation, behaviour and applications. Annual Conference of the Aerosol Society / Aerosol Society (UK) ; 5. Y1 - 1991 SP - 89 EP - 94 CY - Loughborough ER - TY - JOUR A1 - Helsper, Christoph A1 - Fißan, H. J. T1 - Calibration of the Polytec HC-15 and HC-70 Optical Particle Counters / Fißan, H. J. ; Helsper, C. JF - Aerosols in the mining and industrial work environments, Vol. 3. Instrumentation, Marple, Virgil A. ; Liu, Benjamin Y. Y1 - 1983 N1 - International Symposium on Aerosols in the Mining and Industrial Work Environment ; (1981.11.01-06 : ; Minneapolis/Minn.) SP - 825 EP - 829 PB - Ann Arbor Science CY - Ann Arbor, Mich. ER - TY - JOUR A1 - Helsper, Christoph A1 - Fißan, H. J. A1 - Kasper, W. T1 - Calibration of Optical Particle Counters with Respect to Particle Size / Fißan, H. J. ; Helsper, C.; Kasper, W. JF - Particle and Particle Systems Characterization. 1 (1984), H. 1984 Y1 - 1984 SN - 1521-4117 SP - 108 EP - 111 ER - TY - JOUR A1 - Helsper, Christoph A1 - Nießner, R. A1 - Rönicke, G. T1 - Application of a Multistep Condensation Nuclei Counter as a Detector for Particle Surface Composition / Nießner, R.; Helsper, C.; Rönicke, G. JF - Aerosols : science, technology, and industr. applications of airborne particles ; proceedings of the 1. Internat. Aerosol Conference held Sept. 17-21, 1984, Minneapolis, Minn., U.S.A / ed.: Benjamin Y. H. Liu Y1 - 1984 SN - 0444009477 N1 - International Aerosol Conference ; (1, 1984, Minneapolis, Minn.) SP - 63 EP - 66 PB - Elsevier CY - New York [u.a.] ER - TY - JOUR A1 - Helsper, Christoph A1 - Nießner, R. T1 - Application of a Multistep Condensation Nuclei Counter as a Detector for Particle Surface Composition / Nießner, R. ; Helsper, C. JF - Journal of Aerosol Science. 16 (1985), H. 3 Y1 - 1985 SN - 0021-8502 SP - 201 EP - 209 ER -