Beta-ray Attenuation Research Articles

Comparison of PM2.5 Monitoring Data Using Light Scattering and Beta Attenuation Methods: A Case Study in Seoul Metro Subway

A study on monitoring PM2.5 concentrations at an underground subway station using light scattering and beta attenuation methods was conducted. Six optical particle counters (OPCs), which were representative of the light scattering method and had 16 size channels, were installed at different sampling sites in the waiting room and platforms to compare PM2.5 concentrations, determine PM2.5 /PM10 ratios, and characterize the size distribution based on particle number. In terms of the beta attenuation method, a beta-ray attenuation monitor (BAM) was set up at the platform to compare it with OPCs for one month. It was found that 1h-average PM2.5 concentrations varied at different sampling sites depending on PM composition, while 24h-average PM2.5 concentrations were independent of the sampling sites. There was a significant difference between the means of 1h-average PM2.5 concentrations observed by the BAM and OPC when PM2.5 contributed to less than 50% or higher than 80% of PM10. In contrast, the 24h-average PM2.5 concentrations observed by the BAM and OPC showed the same patterns as each other with an insignificant difference. Therefore, an OPC can be used to monitor the 24h-average PM2.5 concentration in an underground subway station. However, the use of OPC to measure the 1h-average PM2.5 concentration should consider PM composition and other factors. In addition, more frequent calibration is needed on a regular basis.

On-line measurement of ultralow mass concentration particulate based on light scattering coupled with beta ray attenuation method

Light scattering method is the most commonly used method for on-line measurement of ultralow particulate matter mass concentration. However, when the particle characteristics change, the effectiveness of the empirical relationship decreases, which would lead to a sizeable deviation. To accurately measure the mass concentration of particulate matter in real-time, a coupling measurement idea of light scattering and beta-ray attenuation is proposed. The beta-ray attenuation is little affected by particle properties and accurately reflects the average PM mass concentration in the measured period. The single calibration method (M1), periodic calibration method (M2), average calibration method (M3), and asymmetric factor calibration method (M4) are formed based on the coupling idea. The results of all methods are perfect when the particle size is unchanged. However, when the particle sizes fluctuate frequently, the results of M1, M2, and M3 deviate seriously from the actual value, and the applicable working conditions have limitations. The results of M4 are in good agreement with the actual value, and the effectiveness is not limited by the particle size. Finally, the prototype based on experimental exploration was developed and had been continuously operated for more than 528 h at a 1000 MW unit of a coal-fired power plant.

Relationships between Meteorological and Particulate Matter Concentrations (PM2.5 and PM10) during the Haze Period in Urban and Rural Areas, Northern Thailand

Meteorological parameters play a crucial role in the ambient air quality of urban and rural environments. This study aims to investigate the relationship between meteorological parameters (including temperature, relative humidity, and wind speed) and the concentrations of PM2.5 and PM10 in the urban area and the rural area, northern Thailand during the haze period (January to April) from 2016 to 2020. Statistical analyses of the Spearman-Rank correlation coefficient and the multivariate gaussian regression were used to investigate the relationships. The secondary data of ambient PM2.5 and PM10 concentration and meteorological parameters were acquired from the Thai Pollution Control Department. The measurements are obtained using the Beta Ray attenuation method. The results showed that approximately 24% to 65% of daily average PM2.5 concentrations in the urban area over the study period exceeded Thailand’s National Ambient Air Quality Standards. The average PM2.5/PM10 ratios in the urban and the rural areas over the haze period were 0.69 and 0.66, respectively. Our analysis established a significant correlation between atmospheric temperature ( r = 0.624) and relative humidity ( r = −0.722) with the concentrations of PM2.5 and PM10. In both areas, PM2.5 and PM10 concentrations were also positively correlated with temperature. In contrast, relative humidity was significantly related with the decrease of PM2.5 and PM10 concentrations. However, wind speed does not affect PM2.5 and PM10 concentrations. Additionally, the daily backward trajectories using the hybrid-single particle Lagrangian integrated trajectory model also demonstrated air mass movement in March mostly came from the southwesterly direction, which moved through the highlands, the large biomass burned areas, upwind neighboring provinces, and transboundary transports before reaching the air monitoring stations. Our findings improve the understanding of particulate matter pollution and meteorological patterns during annual haze periods in the urban and rural areas. We expect the output of this study can help improve existing haze mitigation measures for improving the prediction accuracy of air pollution under variable meteorological parameters.

On-Line Measurement of Ultralow Mass Concentration Particulate Based on Light Scattering Coupled with Beta Ray Attenuation Method

On-Line Measurement of Ultralow Mass Concentration Particulate Based on Light Scattering Coupled with Beta Ray Attenuation Method

Evaluation of Performance of Inexpensive Laser Based PM2.5 Sensor Monitors for Typical Indoor and Outdoor Hotspots of South Korea

Inexpensive (<$300) real-time particulate matter monitors (IRMs), using laser as a light source, have been introduced for use with a Wi-Fi function enabling networking with a smartphone. However, the information of measurement error of these inexpensive but convenient IRMs are still limited. Using ESCORTAIR (ESCORT, Seoul, Korea) and PurpleAir (PA) (PurpleAir U.S.A.), we evaluated the performance of these two devices compared with the U.S. Environmental Protection Agency (EPA) Federal Equivalent Monitoring (FEM) devices, that is, GRIMM180 (GRIMM Aerosol, Germany) for the indoor measurement of pork panfrying or secondhand tobacco smoking (SHS) and Beta-ray attenuation monitor (BAM) (MetOne, Grants Pass, OR) for outdoor measurement at the national particulate matter (PM2.5) monitoring site near an urban traffic hotspot in Daejeon, South Korea, respectively. The PM2.5 concentrations measured by ESCORTAIR and PA were strongly correlated to FEM (r = 0.97 and 0.97 from indoor pan frying; 0.92 and 0.86 from indoor SHS; 0.85 and 0.88 from outdoor urban traffic hotspot). The two IRMs showed that PM2.5 mass concentrations were increased with increased outdoor relative humidity (RH) levels. However, after applying correction factors for RH, the Median (Interquartile range) of difference compared to FEM was (14.5 (6.1~23.5) %) for PA and 16.3 (8.5–28.0) % for ESCORTAIR, supporting their usage in the home or near urban hotspots.

Variability of PM10 in industrialized-urban areas. New coefficients to establish significant differences between sampling points.

One of the main problems that arise in the assessment of air quality in an area is to estimate the number of representative sampling points of each microenvironment within it. We present a new model that reduces the variability and increases the quality of the comparison of the sampling points. The study is based on the comparison between a city in eastern Spain, Vila-real, a macro city in México, Monterrey and the Piemonte region regarding the assessment of PM10 in microenvironments. Vila-real is located in the province of Castellón. This province is a strategic area in the framework of European Union (EU) pollution control. On the other hand, Monterrey in México, located in the northern state of Nuevo León, has several problems with particulate material in the atmosphere produced by the extraction of building materials in the hill that surround the city. Finally, the Piemonte region, which is located in the north of Italy, has to be in consideration due to higher concentrations of PM10 in the Po river basin. In the case of Vila-real the PM10 samples were collected by a medium volume sampler according to European regulations. Particle concentration levels were determined gravimetrically (EN 12341:1999). In the case of Monterrey the PM10 concentrations were determined by Beta Ray Attenuation according to US-EPA regulations. In the Piemonte region, the average concentration of PM10 was also obtained by means of the Beta Ray Attenuation as well as using gravimetric instruments. The methodology carried out in this paper is a useful tool for developing future Air Quality Plans in other industrialised areas.

ARIMA analysis of the effect of land surface coverage on PM10 concentrations in a high-altitude megacity

This paper uses ARIMA models for daily temporal analysis of the effect of land surface coverage (LSC) on PM10 concentrations in a high-altitude megacity. Bogota, the capital of Colombia, is the urban center with the greatest population density and third-highest air pollution levels in Latin America. Six automatic monitoring stations were used; they were equipped with measurement instruments for PM10, temperature and solar radiation as well as wind speed and wind direction. The duration of the sampling period was 6 years. The hourly PM10 sampling system included continuous-monitoring equipment that used beta ray attenuation. We analyzed atmospheric stability and the spatial distribution of LSC (vegetated, non-vegetated, impervious and water bodies) before applying the iterative process of Box-Jenkins for ARIMA models. ARIMA analysis indicates greater persistence in PM10 pollution in the presence of increased vegetated LSC (trees and grasslands); persistence decreased in the presence of more impervious LSC (roofs, pavements and footpaths). PM10 persistence is found to be 2 days (48 h). The best distance to demonstrate these findings is between 50 and 100 m, with respect to the monitoring stations' physical location. Urban areas with a predominance of vegetated LSC register lower PM10 concentrations than urban areas with a predominance of impervious LSC (average daily difference = 42.7%). This study's findings serve as a reference point for the development of differentiated strategies for air pollution control in line with urban LSC.

Comparison of electrostatic charge and beta attenuation mass monitors for continuous airborne PM10 monitoring under field conditions

An electrostatic PM10 mass monitor (EPMM) used for wireless continuous airborne particulate matter monitoring was developed and evaluated in our previous work. However, differences in measured PM10 mass concentrations between the electrostatic charge and the beta ray attenuation methods due to the frequent occurrence of high humidity and temperature in the ambient air in Thailand’s have not been extensively studied in our previous work; and in the literature, it would be necessary to compare the output of the EPMM against the beta ray attenuation mass monitor. In this study, we evaluated the performance of the EPMM simultaneously with a commercially available FH62C14 Beta gauge continuous ambient particulate monitor, Thermo Fisher Scientific Inc., for PM10 measurements at ambient condition in the field. The measurements were made at Yupparaj Wittayalai School, Si Phum, Mueang, Chiang Mai, Thailand from November 16-23, 2015. They showed that the averages of PM10 mass concentrations measured by the EPMM linearly correlate very well with the PM10 mass concentrations measured by the FH62C14. The slopes were 0.9620 and 1.0649 for 1 and 24-hour, respectively, and R2 of 0.8634 and 0.9889 for 1 and 24-hour, respectively. Finally, this comparison proved to be particularly useful in the refinement and design of the EPMM.

Colorado air quality impacted by long-range-transported aerosol: a set of case studies during the 2015 Pacific Northwest fires

Abstract. Biomass burning plumes containing aerosols from forest fires can be transported long distances, which can ultimately impact climate and air quality in regions far from the source. Interestingly, these fires can inject aerosols other than smoke into the atmosphere, which very few studies have evidenced. Here, we demonstrate a set of case studies of long-range transport of mineral dust aerosols in addition to smoke from numerous fires (including predominantly forest fires and a few grass/shrub fires) in the Pacific Northwest to Colorado, US. These aerosols were detected in Boulder, Colorado, along the Front Range using beta-ray attenuation and energy-dispersive X-ray fluorescence spectroscopy, and corroborated with satellite-borne lidar observations of smoke and dust. Further, we examined the transport pathways of these aerosols using air mass trajectory analysis and regional- and synoptic-scale meteorological dynamics. Three separate events with poor air quality and increased mass concentrations of metals from biomass burning (S and K) and minerals (Al, Si, Ca, Fe, and Ti) occurred due to the introduction of smoke and dust from regional- and synoptic-scale winds. Cleaner time periods with good air quality and lesser concentrations of biomass burning and mineral metals between the haze events were due to the advection of smoke and dust away from the region. Dust and smoke present in biomass burning haze can have diverse impacts on visibility, health, cloud formation, and surface radiation. Thus, it is important to understand how aerosol populations can be influenced by long-range-transported aerosols, particularly those emitted from large source contributors such as wildfires.

Calculation of beta-ray attenuation coefficients through thin foils

Through the use of the P 1 approximation to the linear transport equation and assuming that electrons only undergo elastic interactions with atoms, the fraction of transmitted beta-rays through foils is calculated arriving at the well-known exponential dependence with foil thickness. The resulting attenuation coefficients are in good agreement with experimental values.

A system for the sampling of inhalable airborne particles

This paper describes an instrument developed for the semi-continuous measurement of aerosol mass and its classification into three classes. These classes have been chosen to evaluate the health hazards caused by inhalable particles. The instrument takes samples through three probes, each providing different cut-off points (∼15 μm, ∼4 μm, ∼2 μm) and collects airborne particles on circular membrane filters. The increase in weight is measured by the beta-ray attenuation method.

ESR dating for Pleistocene shell fossils and value of annual dose

The ESR dating of aragonite shell fossils from the Middle to Upper Pleistocene deposits are described. Stratigraphically systematic sampling and experiments show that the ESR ages agree with the estimated ages obtained by other dating methods, considering the beta-ray attenuation with the sample thickness and cosmic rays. We can resolve each formation by applying the ESR dating to the field geology. It is necessary for the improvement of accuracy of the ESR dating to examine internal dose rate of shell itself.

Beta dose attenuation and calculations of effective grainsize in brick samples

Abstract An assumption commonly made in estimating the beta-ray contribution to individual quartz grains in bricks and tiles is that prior to extraction all grains used for TL analysis existed as discrete grains embedded in a clay matrix. We have found in many Utah brick samples that this assumption does not hold, and that the grains used for analysis were largely derived from clumps or agglomerations of quartz grains of up to 3 mm in diameter. If we apply beta-ray attenuation factors appropriate for the grain sizes actually analyzed (150–250 μm) rather than those appropriate for the agglomerations from which the analyzed samples were derived, errors in measurement of β-ray contribution in excess of 50% can result. We present details of a computer model for determining effective grain size in bricks and tiles based upon microscopic examination of sample sections.

Laboratory evaluation of instantaneous reading dust monitors

This paper discusses the results of laboratory tests conducted to evaluate three instantaneous reading respirable dust measuring instruments: the SIMSLIN II, the Tyndallometer TM-Digital and the GCA RDM-301. The SIMSLIN II and Tyndallometer employ the principle of light scattering to measure the mass concentration of respirable dust; the GCA uses the principle of beta-ray attenuation to measure mass concentration. Simultaneous measurements with a homogenous grouping of instruments were made in coal dust aerosols ranging in concentration from 1.0 to 11.0 milligrams per cubic meter to establish between-instrument variability and correlation with the Isleworth Type 113A Gravimetric Respirable Dust Sampler (MRE). Between-instrument variability, expressed as the coefficient of variation, averaged 13.5 percent for the SIMSLIN II, 6.0 percent for the Tyndallometer and 13.1 percent for the GCA. Relationships established from comparative measurements with the MRE showed on the average that measurements with the SI...

Instantaneous dust exposure monitors

This is a review of investigations conducted to evaluate portable, direct reading instruments employing the principles of light scattering and the attenuation of beta-rays to measure the respirable mass concentration of airborne particulates. Data are presented on comparative measurements obtained with several different models of beta-ray attenuation instruments manufactured by the GCA Corporation and light scattering instruments manufactured by GCA Corporation, USA, Ernst Leitz, GmbH, Germany, Rotheroe and Mitchell, England, and Sibata Chemical Apparatus Manufacturing Company, Ltd., Japan, using aerosols of coal, limestone, Arizona road dust, and silica. The effect of aerosol parameters (concentration, size distribution, index of refraction) on instrument calibration and precision are discussed.

Estimating Pasture Yield In Situ by Beta Ray Attenuation Techniques1

Agronomy JournalVolume 57, Issue 5 p. 512-513 Note Estimating Pasture Yield In Situ by Beta Ray Attenuation Techniques1 G. O. Mott, G. O. MottSearch for more papers by this authorR. F. Barnes, R. F. BarnesSearch for more papers by this authorC. L. Rhykerd, C. L. Rhykerd Professor of Agronomy; Assistant Professor of Agronomy and Research Agronomist, Crops Research Division, ARS, USDA; and Associate Professor of Agronomy, respectively, Purdue University, Lafayette, Indiana.Search for more papers by this author G. O. Mott, G. O. MottSearch for more papers by this authorR. F. Barnes, R. F. BarnesSearch for more papers by this authorC. L. Rhykerd, C. L. Rhykerd Professor of Agronomy; Assistant Professor of Agronomy and Research Agronomist, Crops Research Division, ARS, USDA; and Associate Professor of Agronomy, respectively, Purdue University, Lafayette, Indiana.Search for more papers by this author First published: 01 September 1965 https://doi.org/10.2134/agronj1965.00021962005700050036xCitations: 3 1 Contribution from Indiana Agricultural Experiment Station, Journal Paper No. 2492. The authors wish to acknowledge the technical assistance of James R. Eaton, Professor of Electrical Engineering, and Paul Ziemer, Assistant Professor of Bionucleonics, Purdue University, Lafayette, Indiana. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume57, Issue5September‐October 1965Pages 512-513 RelatedInformation