A new versatile condensation particle counter for research and environmental monitoring

Transcription

1 A new versatile condensation particle counter for research and environmental monitoring, Maximilian Weiss Palas GmbH, Greschbachstr. 3b, Karlsruhe, Germany,

2 Overview 1. Motivation (why count & size airborne nanoparticles continuously?) 2. Applications 3. Palas UF-CPC: Design and function 4. Field measurement with two UF-CPCs (water & butanol) simultaneously 5. Conclusions

3 Motivation human health Inhalable Fraction Inhaled dust Thoracic Fraction Fraction passing the larynx and getting into the thorax Alveolic Fraction The fine particles, entering the more than 300 Million alveolic bubbles INRS France (Olivier Witschger): Deposition of particles in the human respiratory tract

4 Another motivation the existing experience Leander Mölter started Palas in 1983 (29 years ago) > 26 years: Enlarging particles via condensation Untersuchung zur Erzeugung von monodispersen NaCl-Aerosolen mit einem modifizierten Sinclair-LaMer Generator. Studienarbeit von R. Kubat bei Palas in Zusammenarbeit mit Prof. Wurz, Universität (TH) Karlsruhe im Jahre > 24 years: Measuring the electrical charge of aerosols Determination and Neutralisation of the Charge produced by the Dispersion of Powder. Journal of Aerosol Science 6 (1987), Ch. Helsper, W. Mölter > 23 years: Optical particle measurement with white light Streulicht-Partikelgrößen-Zählanalyse als Methode für In-Situ-Messungen in Gas-Partikel-Strömungen. Technisches Messen tm 56 (1989) 5, H. Umhauer Today: New family of nanoparticle measurement devices UF-CPC Condensation Particle Counter U-SMPS Scanning Mobility Particle Sizer Charme Reference Aerosol Electrometer

5 Instrument setup for a CPC calibration realized with Palas equipment Calibration setup according to ISO CD Primary aerosol source Aerosol generator Aerosol conditioning Bipolar charger DEMC FCAE or Reference CPC Flow splitter Manifold with mixing orifice Number concentration control (dilution) Test CPC Make-up air supply or bleed Climatic chamber (optional) Valve with mixer Air to or from setup

6 U-SMPS for environmental monitoring Comparing the U-SMPS with two reference systems at the IfT in Leipzig (Prof. Wiedensohler)

7 Further applications for nanoparticle measurement systems - Aerosol research particle formation, behaviour - Environmental monitoring (municipalities, networks) [CPCs: CEN/TC 264/WG32] European Supersites for Atmospheric Aerosol Research 34 CPCs 19 SMPS Systems - Process monitoring & control - Workplace safety - Emission studies

8 Further applications for nanoparticle measurement systems - Filter testing - Controlled environments (e.g. hospitals) - Indoor air quality - Inhalation studies / Toxicology - Workplace safety - Emission from e.g. laser printers

9 dn in 1/cm³ - Emission from e.g. laser printers CPC 1 CPC 2 (*1.2) CPC 1 CPC 2 (*1.2) 2011_02_10_2 00:00 05:00 10:00 15:00 20:00 25:00 Zeit in min 2011_02_08_1 Source: Presentation by Stefan Seeger at Palas ATS Seminar 2011 Note: the upcoming Blue Angel test will prescribe a Butanol CPC for this measurement.

10 Counting nanoparticles makes use of condensation Since the scatter intensity decreases with the sixth power of the particle size, optical aerosol spectrometers cannot classify particles below 64 nm. However, particles can be enlarged via condensation (also in nature).

11 Liquid pump Number determination Technical realisation: Condensation particle counter optical sensor with LED-light technology LED photomultiplier condenser working fluid condenses onto the nanoparticles forming droplets Palas UF-CPC - measures the total number concentration - from 4.5 nm - flexibility in the choice of the working fluid - single particle counting up to 10 6 P/cm 3 - intuitive operation via 7 touch panel display - integrated data logger - droplet size distribution reservoir with working fluid, e.g. butanol, water saturator with constantly heated helical U-shaped channel aerosol flow

12 The inside of the UF-CPC optical sensor condenser inlet saturator reservoir

13 Single particle counting up to 10 6 particles/cm 3 due to modular sensor design LED optical sensor condenser photomultiplier aerosol flow inlet saturator reservoir Counter C max [P/cm 3 ] UF-CPC Up to 10 7 particles/cm 3 photometrically / nephelometer mode UF-CPC Up to 10 7 particles/cm 3 photometrically / nephelometer mode UF-CPC Up to 10 7 particles/cm 3 photometrically / nephelometer mode

14 Measurement location: Mail distribution center Description: the mail distribution center is located in an industrial area, about 400 m away from a high traffic highway. A night club is about 500 m away. No residential traffic has to pass through the area (next residential housing about 1 km away).

15 ratio water/butanol Results Saturday Sunday Monday UF-CPC (butanol) UF-CPC (water)

16 Conclusions Presented UF-CPC (universal fluid condensation particle counter): - unique, patented way of providing the working fluid (US 7,543,803 B2, DE A1) - counts submicron sized particles but also reports droplet size - single particle counting up to 1,000,000 particles/cm 3 due to modular design - user can operate the same instrument with butanol, isopropanol or water - Application: monitoring ambient number concentrations near a mail distribution center

17 Thank you very much for your attention!