Electric low pressure impactor

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An electrical low pressure impactor ( English Electrical Low Pressure Impactor , ELPI) is a device for recording the mass size distribution of dust particles in gases. With its help, particle size distributions can be determined almost in real time as a function of the particle diameter.

Measuring principle

A low-pressure electrical impactor is essentially a low-pressure cascade impactor in which the particles must be electrically charged prior to deposition. Before the gas flow is passed over several impactor stages , the particles it contains are electrically charged by means of a corona discharge . If a particle is deposited on a baffle plate, it generates a current signal that is detected by an electrometer connected to the baffle plate .

Electric low-pressure impactors allow the real-time identification of particles. The response times of these devices are around one second. They can be used for both emission and immission measurement.

Electric low pressure impactors record the respective aerodynamic diameter of the detected particles. They can also be used to characterize test aerosols . The particle size range to be detected is between 6 nm and 10 µm .

literature

  • VDI 3867 Sheet 6: 2012-12 Measurement of particles in the outside air; Determination of the particle number concentration and number size distribution of aerosols; Electrical Low Pressure Impactor (ELPI) (Measurement of particles in ambient air; Determination of the particle number concentration and number size distribution of aerosols; Electrical Low Pressure Impactor (ELPI)). Beuth Verlag, Berlin. ( Summary and table of contents online )

Individual evidence

  1. ↑ Jozef S. Pastuzka: inertial impaction. In: Kvetoslav R. Spurny : Advances in Aerosol Filtration. Lewis Publishers, Boca Raton 1998, ISBN 0-87371-830-5 , pp. 437-452.
  2. ↑ a b c d Johannes Pelzer, Oliver Bischof, Willem van den Brink, Martin Fierz, Harald Gnewuch, Henna Isherwood, Markus Kasper, Andreas Knecht, Thomas Krinke, Axel Zerrath: Devices for measuring the number concentration of nanoparticles. In: Hazardous substances - cleanliness. Air . 70, No. 11/12, 2010, ISSN  0949-8036 , pp. 469-477.
  3. ↑ James H. Vincent: Aerosol Sampling - Science, Standards, Instrumentation and Applications . John Wiley & Sons, Chichester 2007, ISBN 978-0-470-02725-7 , p. 457.
  4. ↑ Albert Hellmann, Kilian Schmidt, Siegfried Ripperger, Johannes Pelzer, Klaus W. Müller: Generation of defined reference aerosols of ultra-fine particles with a spark generator. In: Hazardous substances - cleanliness. Air. 72, No. 11/12, 2012, ISSN  0949-8036 , pp. 467-472.
  5. ↑ VDI 3867 sheet 6: 2012-12 Measurement of particles in the outside air; Determination of the particle number concentration and number size distribution of aerosols; Electrical Low Pressure Impactor (ELPI) (Measurement of particles in ambient air; Determination of the particle number concentration and number size distribution of aerosols; Electrical Low Pressure Impactor (ELPI)). Beuth Verlag, Berlin, p. 2.