We report Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) measurements of the composition ambient 10–33 nm diameter particles formed from nucleation on 16 March 2006 in Tecamac, Mexico during Megacity Initiative: Local and Global Research Observations (MILAGRO) field study. On this day, nucleated contained far more organics than sulfates: average ion molar ratios with measurement uncertainties for nitrate, sulfur species were 6 ± 2%, 84 5%, 10 1%, respectively. The measured...

The effect of working fluid on size-dependent activation efficiencies with the laminar flow ultrafine condensation particle counter described by CitationStolzenburg and McMurry (1991) was studied theoretically experimentally. Criteria considered include tendency to avoid homogeneous nucleation within condenser toxicity. fluids that were identified have vapor pressures below butanol, so particles grow smaller sizes are more difficult detect optically. Therefore we use a second, conventional...

A method to estimate nanoparticle diameter growth rates (GR) during new particle formation (NPF) events from the measured dependence of charged fraction, f , on size, D p is introduced. The especially useful for observations intense production rates, when mode in distribution newly formed particles does not grow monotonically with time. This assumes that observed profile versus nucleation and period controlled by condensational growth, ion‐particle combination/recombination, scavenging...

Mass identified ion cluster distributions were measured under ambient atmospheric conditions and compared with model predictions based on laboratory thermodynamics data. The results are shown from several days where sulfur concentrations high thus ion‐induced growth was anticipated. Atmospheric gas phase sulfuric acid, temperature, relative humidity, SO 2 , mobility of ions small charged particles, aerosol size also in support the calculations. agreement measurement for first second acid...

This paper investigates the role of ion‐induced nucleation (IIN) in new particle formation events observed near ground level at a sampling site located Boulder, Colorado (14 March 2004 to 27 October 2005). Measurements mobility distributions small and intermediate ions (0.4–6.3 nm), size total particles (3 nm 5 μ m), charged fractions (2.5–25 nm) were carried out. The relative contributions neutral IIN inferred using both qualitative quantitative analyses. First, simple theoretical analysis...

In this study, we present a traceable method for determining the counting efficiency of optical particle size spectrometers (OPSS), also known as aerosol spectrometers. The primary standard consists an generation setup, vertical flow tube homogenization and reference counter. OPSS under testing counter sample simultaneously through specially designed isokinetic sampling probes at number concentrations ranging from 0.5 cm−3 up to several hundred particles per cm3 (depending on size)....

Several automated pollen monitors have recently become available, most using conventional and/or machine-learning algorithms to detect and classify their taxa. An international intercomparison campaign was organised by the EUMETNET AutoPollen Programme ADOPT COST Action in Munich (March–July 2021) (Maya-Manzano et al. 2023). The study showed that some automatic systems, especially those built-in correction factors compensate for losses of sampling, detection classification, agreed...

An ultrafine, water-based condensation particle counter (U-WCPC, TSI Model 3786) has been compared to a butanol-based ultrafine (U-BCPC, 3025) for measurement of atmospheric and freeway-tunnel aerosols. The U-WCPC utilizes warm, wet-walled growth tube activate grow particles through water in laminar-flow. It an aerosol sampling rate 0.3 L/min, nominal detection limit near 3 nm. Several field comparisons were made the instrument with same limit. For measurements size-selected aerosols...

The AIST-inkjet aerosol generator (IAG) can generate highly monodisperse solid or liquid particles in the particle diameter range from 0.3 to 20 μm at precisely known generation rates. device has been developed for evaluating counting efficiencies of optical and condensation counters. Particle efficiency IAG is defined as number generated by one voltage pulse sent an inkjet head. 95% confidence interval were 0.998 ± 0.006 within 0.4 10 range. remained close unity when droplet rates 20–500...

We carried out a set of experiments to compare three particle number concentration standards (NCSs) by calibrating the same condensation counter (CPC) unit (Model 3772, TSI Inc., Shoreview, MN, USA). The were, in order operation size range, primary NCS National Institute Advanced Industrial Science and Technology (AIST, Japan), Single Charged Aerosol Reference (SCAR) (Finland), Inkjet Generator (IAG) AIST. results obtained with 3 were found agree at all overlapping sizes within uncertainty...

A method to determine the cutoff diameter and counting efficiency of single-particle optical particle counters (OPC) is presented. An aerodynamic aerosol classifier (AAC) coupled with an atomizer was used generate monodisperse dioctyl phthalate particles a condensation counter (CPC) as reference instrument. This accurate for capturing OPCs at lower size ranges determining diameter. The CPC found be poor instrument larger than 1 µm in which case inkjet generator (IAG) source Two different...

A butanol-type ultrafine condensation particle counter (UCPC, Model 3776, TSI, Inc., Shoreview, MN, USA), which can achieve a 50% detection efficiency diameter (d50) of 2.5 nm using capillary-sheath structure, was modified and tested in the laboratory for airborne measurements. The aerosol flow rate through capillary is key factor affecting quantification number concentrations. pressure-dependent correction determined newly added mass meter sheath external calibration system. effect...

Schemes of conditional data processing are evaluated based on either the peak-to-base ratio or signal-to-noise as a metric for analyte detection in single-shot laser-induced breakdown spectra. The signal investigated is 288.1-nm Si I emission line provided by an aerosol stream monodisperse 2.5-microm-sized silica microspheres. Both and spectral region corresponding to continuum used evaluate statistical distribution noise. probability false hits determined evaluating various thresholds. As...

Chromated copper arsenate (CCA) has been the predominant wood preservative used in North America recent years. The emission of volatile metals and leaching from combustion ash CCA-treated pose serious concerns. In this work, mineral sorbents were evaluated for their capabilities to control both problems. Results thermodynamic analyses suggested that alkali alkaline earth metal-based can potentially react with during combustion. Experiments conducted by mixing burning including lime soda a...

Abstract We report on an inter-laboratory comparison for the calibration of light-scattering optical particle counters measuring number concentration airborne particles in size range 300 nm–5 µm. This comparison, registered as EURAMET pilot study Nr. 1453, is important first step towards internationally recognized SI traceability measurement low concentrations encountered clean-room facilities. The participating metrology laboratories NMIJ (Japan), DFM (Denmark) and METAS (Switzerland) each...

This study introduces the method to evaluate counting efficiencies of optical particle counters (OPCs), , at diameter greater than 1 μm by using an inkjet aerosol generator (IAG). demonstrates evaluations 5 and 10 in volume equivalent diameter. The chemical composition particles is either sodium chloride or lactose monohydrate. flowrate IAG set 0.3 L/min, delivered OPC with sampling 6 L/min (Omron, ZN-PD50S). mismatch flowrates compensated for adding particle-free air a laminar flow chamber....

A method was developed to verify the viable counts of BioTrakTM (TSI Model 9510-BD) without using test bacteria. In this method, an inkjet aerosol generator (IAG) used deliver a known number particles BioTrak in given sampling time. An IAG generates two types monodisperse particles, inert and fluorescent particles. Inert consist chemical substance that does not emit fluorescence when are irradiated by laser beam BioTrak. were whether false positive or not. Depending on version discrimination...

Radionuclides released during the Fukushima Daiichi nuclear accident caused altitude-dependent surface contamination in mountainous areas of Japan. To explore possible cloudwater deposition that formed a distinctive profile, data from pollen sensors deployed nationwide were analyzed. Utilizing polarization scattered light, Cedar and water droplets distinguished. On March 15, when was simulated previous studies, dense clouds with high droplet number concentrations observed outside 137Cs...

The aim of this study was to establish traceable number concentration measurements airborne particles beyond 10 μm in particle size. To end, the primary standards for at National Metrology Institutes Switzerland and Japan were further developed extend their measurement capabilities. Details on upgraded setup are provided. An inter-comparison two using an optical counter as transfer standard showed that these agree well within stated uncertainties polystyrene (PS) equivalent diameter 15 µm....

Abstract The concentration of nanometer-sized particles is frequently measured in terms particle number using well-established measuring instruments, such as condensation counters (CPCs). Traceability for these measurements can be achieved by means calibration against a reference aerosol electrometer starting at concentrations >1000 cm −3 . Here, two independent methods extending traceability down to 1 are described. first method relies on custom-made, optical counter while the second...

The classical nucleation theory predicts that a decrease in temperature under constant saturation ratio increases the energy barrier for homogeneous to occur; therefore lower would allow higher inside condensation particle counter (CPC) while suppressing homogenous of working fluid vapor below threshold value. On other hand, also heterogeneous occur, which potentially minimum detectable size CPC. Accordingly, it is important investigate experimentally whether super-saturation decreases or...

To simulate and better understand toxic metal–sorbent particle interactions, laser-induced breakdown spectroscopy (LIBS) was implemented to quantify trace amounts of manganese enriched on the surface concomitant silica microsphere particles in an optical access laboratory-scale combustion system. Flame atomic absorption measurements verified that introduced nanoparticles were extensively dissociated within high-temperature region H2–O2–N2–air flame. LIBS-based conditional spectral analysis...