Aerosol photometer

Aerosol photometer — light-scattering type with a threshold sensitivity of at least 10 mg/1. Capable of measuring concentrations in the range of 80 to 120 mg/1, and with air sample flow rate of 1 fC + 10%/min. 

Introduce DOP aerosol upstream of the filter through a test port and search for leaks downstream with an aerosol photometer. Filter testing shall be performed after operational air velocities have been verified and adjusted where necessary. 

Open the appropriate number of nozzles until a DOP challenge concentration of 100 mg/liter of air is reached. This challenge concentration is measured upstream of the HEPA filter and is evidenced by a reading between 4 and 5 on the logarithmic scale of the aerosol photometer. 

A popular method for certifying the integrity of the filter installation uses a polydisperse aerosol, created by blowing air through liquid (e.g., poly-alpha-olefin) introduced into the upstream ductwork, followed by scanning the entire downstream side of the filter face and periphery with a probe nozzle of an aerosol photometer. This testing will identify leaks caused by damage due to... 

The Sinclair-Phoenix aerosol photometer brought the light to a focus at the sample cell, with a diaphragm stop placed in the optical path so that a diverging cone of darkness encompassed the light-collecting lens of the... 

Dioctyl phthallate is not now used for this purpose because of a risk to operator health. An aerosol of mineral oil is now used. It is provided from generators that heat the oil and then vaporize it by entrainment in an inert gas stream. The particle size range is from 0.1 to 1.25 J.m with a median diameter of 0.3 pm. Aerosol particles passing through a Alter are detected with an aerosol photometer. 

HEPA filter integrity testing is performed at 6-month intervals on level I and level II HEPA filters. HEPA filter testing includes Measuring (Machines, Eilters, Diffusers) Inlet and Outlet Air Velocity or Volume and Integrity Test of HEPA Filters Using Aerosol and Photometer. Refer to (provide reference to attachment no.). 

A challenge aerosol concentration of 10 to 20 Xg/l of air is satisfactory. In upstream position (gain adjustment), adjust the concentration immediately upstream from the filter to read 100% on the photometer. If the upstream concentration of 100% cannot be reached, increase generator output. 

Pinatubo volcanic aerosol Aircraft observations with impactors and a suntracking photometer, J. Geophys. Res 95,129I5-12922. 

The most often measured property of the LRT wildfire smokes is the mass concentration of aerosol particles in fine (PM2.5) or submicron (PMi) or in fine and coarse size fraction together (PM10). The mass concentration is usually determined either with a tapered element oscillating microbalance (e.g., [19]), or with the instruments based on p-attenuation (e.g., [13]). In addition to mass concentration, real-time instruments can measure other physical properties of particles, e.g., number concentration of particles in different size fractions using a differential mobility particle sizer [13] or the optical characteristics of smoke by a nephelometer [32]. Ground-based instruments also include remote sensing instruments such as sun photometers [32],... 

Organic carbon (OC) and elemental carbon (EC) concentrations in smoke aerosol can be measured by using a semicontinuous thermal-optical OC/EC instruments [18]. Water-soluble organic carbon (WSOC) and water-soluble ions can be detected in smoke plumes with a PILS combined with a total organic carbon analyzer [30] and IC [19]. Besides smoke-specific tracers, the HR-ToF-AMS enables to study the concentrations of organic matter (OM), nitrate, ammonium, sulfate, and chloride in smoke particles [30]. Black carbon (BC) can be measured in real-time with several instruments, e.g., with aethalometer [19], multi-angle absorption photometer [29], and particle soot absorption photometer [25]. 

Toledano C, Cachorro VE, Gausa M, Stebel K, Aaltonen V, Berjon A, Ortiz de Galisteo JP, de Frutos AM, Bennouna Y, Blindheim S, Myhre CL, Zibordi G, Wehrli C, Kratzer S, Hakansson B, Carlund T, de Leeuw G, Herber A, Torres B (2012) Overview of sun photometer measurements of aerosol properties in Scandinavia and Svalbard. Atmos Environ 52 18-28... 

The Brice-Phoenix light scattering photometer and the Absolute light scattering photometer were designed for the measurement of attenuation, dissymetry and depolarization. The former has also been used to determine the particle size distribution of an aerosol at various levels in a flowstream through a column [125]. 

Aerosol concentrations and size distributions can be investigated remotely using sun-photometry. Characterization of volcanic aerosol is important in smdies of plume chemistry, atmospheric radiation, and the environmental and health impacts of particle emissions. Watson and Oppenheimer (2000, 2001) used a portable sun-photometer to observe tropospheric aerosol emitted by Mt. Etna. They found distinct aerosol optical signatures for the several plumes emitted from Etna s different summit craters, and apparent coagulation of particles as the plume aged. More recently. Porter et al. (2002) have obtained sun-photometer and pulsed lidar data for the plume from Pu u O o vent on Kilauea, Hawaii, from a moving vehicle in order to build profiles of sulfate concentration. 

Porter J. N., Horton K., Mouginis-Mark P., Lienert B., Lau E., Sutton A. J., Elias T., and Oppenheimer C. (2002) Sun photometer and lidar measurements of the plume from the Hawaii Kilauea volcano Pu u O o vent estimates of aerosol flux rates and SO2 lifetime. Geophys. Res. Lett. Doi 10.1029/ 2002GL014744 (23 August 2002). 

We consider the case of an aerosol illuminated by a collimated light source of a given wavelength. The experimental arrangement is shown schematically in Fig, 5.6. A photometer of this type installed in a smoke stack or duct would be suitable for measuring the attenuation... 

A salt aerosol is generated in an enclosure, usually up to a concentration of 13 mg m 3, with a particle mass median diameter of 0.3 to 1.3 pm, depending on the aerosol generator used. The subject dons the respirator, enters the enclosure and performs a set of simple exercises while the salt concentration inside and outside the respirator are measured by flame photometry. The Dstl, Porton Down uses a specially built high-sensitivity flame photometer to measure very low salt concentrations (and hence to confirm very high PFs). 

KRUPA I do not know exactly how much SO3 is in the plume, but EPA flew the plume last summer and we also have stack analysis on it. One way people measure sulfate is to modify a flame photometer, one that would normally measure S02 An electrical chopper is used in front of the flame photcaneter and the aerosol is neutralized. Subsequently, total sulfur versus SO2 is measured. The SO2 concentration is subtracted from the total sulfur to calculate SO4 levels. The only person I know that might have done significant work on this is Etou at the University of Utah. Etough has found that sulfite, up to 30 in some smelters, may exist as a stable complex with transient metals, such as lead, copper, iron [Atmos. Environ. 12 263-272 (1978)] and Jake Hales has done the same thing on the MAP 3S study over Lake Michigan in precipitation. [Atmos. Environ. 12 389-400 (1978)]. Data of Hales indicate that maybe 10-20 of the sulfur could be as a stable sulfite. 

In flame emission spectrometry, the sample solution is sprayed or aspirated into a flame as a fine mist or aerosol. The sample is vaporized in the flame, and atomized by a combination of heat and the action of a reducing gas. The atoms are excited into higher electronic states by the heat, and as they revert to the ground state they emit photons, which are measured by the detector. The layout of a flame photometer is shown in Figure 2. 

Samples generally are introduced into flames in the form of solutions, by spraying or nebulizing either directly into the flame along with the fuel or indirectly into a chamber to allow coarser droplets to settle out, with the finer aerosol and fuel passing on to the burner. The direct total consumption approach was widely used in emission until the advent of atomic absorption, for which it was less suitable. It was turbulent, audibly noisy, and gave less complete vaporization of solutes. This type of sample introduction is still used in some clinical flame photometers. 

Yang, Y., Xiao, S., Zhang, Y. et al. (2013). In situ detection of trace aerosol uranium using a handheld photometer and solid reagent kit. Anal. Methods 5,4785-4789. 

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