TY - JOUR A1 - Helsper, Christoph A1 - Fißan, H. J. A1 - Muggli, J. A1 - Scheidweiler, A. T1 - Verification of Ionization Chamber Theory JF - Fire Technology. 19 (1983), H. 1 Y1 - 1983 SN - 1572-8099 SP - 14 EP - 21 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 - 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 - 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 - 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. 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 - TY - JOUR A1 - Helsper, Christoph A1 - Bartz, H. A1 - Fißan, H. J. A1 - Kousaka, Y. (u.a.) T1 - 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. JF - Journal of Aerosol Science. 16 (1985), H. 5 Y1 - 1985 SN - 0021-8502 SP - 443 EP - 456 ER - TY - JOUR A1 - Helsper, Christoph A1 - Nießner, R. T1 - On the Influence of the Vapour Substance on the Behaviour of an Expansion Type Condensation Nucleus Counter JF - Journal of Aerosol Science. 16 (1985), H. 5 Y1 - 1985 SN - 0021-8502 SP - 457 EP - 461 ER - TY - JOUR A1 - Helsper, Christoph A1 - Wiedensohler, A. A1 - Lütkemeier, E. A1 - Feldpausch, M. T1 - Investigation on the Bipolar Charge Distribution at Various Gas Conditions / Wiedensohler, A.; Lütkemeier, E.; Feldpausch, M. ; Helsper, C. JF - Journal of Aerosol Science. 17 (1986), H. 3 Y1 - 1986 SN - 0021-8502 SP - 413 EP - 416 ER - TY - CHAP A1 - Helsper, Christoph A1 - Fissan, H. J. A1 - Franzen, H. ED - Benarie, Michel M. T1 - Particle Size Distributions of Combustion Aerosols T2 - Atmospheric Pollution 1978 : Proceedings of the 13th International Colloquium; 25-28 April 1978; Paris, France; Edited by Michel M. Benarie N2 - 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. Y1 - 1978 SN - 0-444-41691-9 U6 - https://doi.org/10.1016/S0166-1116(08)71583-8 SP - 263 EP - 266 PB - Elsevier CY - Amsterdam ER -