TY - JOUR A1 - Helsper, Christoph A1 - Dreiling, V. A1 - Haller, P. A1 - Kaminski, U. T1 - Intercomparison of Eleven Condensation Nucleus Counters / Dreiling, V. ; Haller, P. ; Helsper, C.; Kaminski, U. ; Plomp, A. ; Raes, F. ; Roth, C. ; Schier, J. ; Schürmann, G. JF - Journal of Aerosol Science. 17 (1986), H. 3 Y1 - 1986 SN - 0021-8502 SP - 565 EP - 570 ER - TY - JOUR A1 - Helsper, Christoph A1 - Mölter, W. T1 - Determination and Neutralization of the Charge Produced by the Dispersion of Powders JF - Journal of Aerosol Science. 18 (1987), H. 6 Y1 - 1987 SN - 0021-8502 SP - 877 EP - 880 ER - TY - JOUR A1 - Helsper, Christoph A1 - Mölter, W. A1 - Haller, P. T1 - Representative Dilution of Aerosols by a Factor of 10,000 JF - Journal of Aerosol Science. 21 (1990), H. Suppl. 1 Y1 - 1990 SN - 0021-8502 SP - 637 EP - 640 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 - 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 - 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 -