diffuse sampling Articles

  • Area Monitoring: Diffusion Sampling

    Indoor and outdoor gas hazards that exist in open areas are usually monitored using diffusion-type sensors. A diffusion sensor has no active sample-drawing system; diffusion sensors rely on the ambient air movement and pressure to deliver the sample to the sensing element. Diffusion-type sensors are a reliable and cost-effective way to monitor open area gas hazards. When installing diffusion ...

  • ITRC guidance document for passive diffusion sampling

    The ITRC in conjunction with the USGS, US EPA, US Army Corp of Engineers, and other prominent federal and state groups have released a comprehensive document, based on significant case studies and backed up by controlled laboratory testing, for the use of polyethylene membrane passive diffusion samplers, such as the EQUILIBRATOR Diffusion Sampler manufactured by EON Products, Inc. Part 1 of the ...


    By EON Products Inc.

  • ITRC position paper for passive diffusion sampling, 2002

    This document is intended to facilitate the use of polyethylene diffusion bag (PDB) samplers for long-term monitoring (LTM). The guidelines presented in Sections 2 and 3 relate to appropriate implementation, data interpretation, and regulatory issues of concern. Although diffusion samplers can be useful for many different activities and have membranes composed of various materials, this ...


    By EON Products Inc.

  • ITRC technical regulatory guidelines for passive diffusion sampling, 2004

    Polyethylene diffusion bag (PDB) samplers are low-density polyethylene bags containing deionized water, used to collect water samples in groundwater wells for laboratory analyses of volatile organic compounds (VOCs). PDB samplers are passive devices, relying on the movement of groundwater from the aquifer or water-bearing zone through the screen or open interval of a well. VOCs in groundwater ...


    By EON Products Inc.

  • Mcclellan air force base diffusion

    Parsons Engineering Science, Inc. (Parsons ES) was retained by the US Air Force Center for Environmental Excellence Technology Transfer Division (AFCEE/ERT) to perform an evaluation of passive groundwater diffusion sampling technology. The diffusion sampler evaluation was funded under Contract F11623-94-D0024, Delivery Order RL72, as part of the AFCEE/ERT Remedial Process Optimization (RPO) ...


    By EON Products Inc.

  • Diffuse reflectance spectroscopy using a handheld FTIR

    As has been previously discussed (1), FTIR spectroscopy is emerging as a technique that can be effectively used for applications and/or in locations that heretofore would be considered too demanding. The development of portable FTIRs, and more recently handheld FTIRs, is significant because it enables this powerful analytical technique to solve problems for a whole range of new applications, both ...


  • Rotating angled plate diffusing wave spectroscopy

    Solid–like non–ergodic samples can be difficult to study using standard single speckle diffusing wave spectroscopy as the measurement may lack requisite ensemble averaging. We demonstrate here that this required ensemble averaging can be induced by translating the speckle over the collection optics so that multiple speckles are observed over the duration of the experiment. Translation is achieved ...


    By Inderscience Publishers

  • Ammonia diffusion through Nalophan™ bags

    The aim of the work is to verify the diffusion rate of ammonia through the Nalophan™ film that constitutes the sampling bag, considering storage times ranging from 1 to 26 h. The ammonia decay over time was evaluated using gas-chromatography for the quantification of ammonia concentration inside the bag. The research assesses the roles of both of ammonia and water concentration gradients ...


    By IWA Publishing

  • Exposure to environmental tobacco smoke at work, at home, and during leisure time: personal exposure measurements by diffusive sampling of airborne 3-Ethenylpyridine

    Environmental tobacco smoke (ETS) is associated with an increased risk of several diseases. In 2002, the ETS exposure level was studied in a Finnish cross-sectional population sample with a sub-sample of currently working nonsmokers. In all, 123 nonsmokers (25-64 years) reporting at least 1 h of daily exposure to ETS participated in personal exposure measurements. Two 3 M organic vapor monitors, ...


    By SAGE Publications

  • Field trial of a new commercially available diffusive ground-water sampler

    Field trials of a new commercially available diffusive ground-water sampling device were conducted at two industrial properties in the Blue Ridge Province of North Carolina. The test sites have extensive monitoring well networks and more than five years of historical water quality data. Volatile organic compounds (VOCs) including purgeable aromatics (petroleum hydrocarbons) and halogens ...


    By EON Products Inc.

  • Marine sediment components: identification and dispersal assessed by diffuse reflectance spectrophotometry

    Analysis of deep-sea sediments presents a number of exceptional challenges. Generally, the amount of material available is small and has to be shared among investigators. Also, deep-sea sediment contains a diverse range of components from a variety of sources including lithogenous, biogenous and hydrogenous. Finally, large number of samples is frequently analysed making rapid analysis a ...


    By Inderscience Publishers

  • Influences of inter-organisational relationships in technology diffusion: the network perspective

    A conceptual challenge in exploring the role of interorganisational relationships is adapting an inherently level-ambiguous concept to incorporate distinct interpersonal- and interorganisational-level concepts. As compared to studies that have focused on large enterprises in developed countries, we define technology diffusion of small-sized firms whose resources are limited as distinct constructs ...


    By Inderscience Publishers

  • Diffuse phosphorus models in the united states and europe: their usages, scales, and uncertainties

    Received for publication February 3, 2008. Today there are many well-established computer models that are being used at different spatial and temporal scales to describe water, sediment, and P transport from diffuse sources. In this review, we describe how diffuse P models are commonly being used in the United States and Europe, the challenge presented by different temporal and spatial scales, ...

  • ITRC technology overview of passive sampling technologies

    This document presents technical overviews of 12 passive sampling technologies. It describes each technology’s basis of operation, intended applications, advantages, limitations, and development status. Contacts for additional information are provided. This overview is an outgrowth of interest and information generated in preparation of the ITRC Technical and Regulatory Guidance for Using ...


    By EON Products Inc.

  • Evaluating Leaks in a Soil Gas Sampling Train

    ABSTRACT The current advisory for active soil gas investigations in California requires leak tests to be conducted at eveiy soil gas probe while taking a sample. A leak may allow ambient ak into the sample train thus diluting the soil gas and underestimating the results. Also, the leak check compound itself may have impurities thereby contaminating the sample. The advisoiy suggests leak ...


    By Eurofins Air Toxics Inc

  • Residential Vapor Intrusion Evaluation: Long Duration Passive Sampling v. Short Duration Active Sampling

    Abstract Sampling indoor air for potential vapor intrusion impacts using current standard 24-hour sample collection methods may not adequately account for temporal variability and detect contamination best represented by long-term sampling periods. Mr. Henry Schuver of the U.S. Environmental Protection Agency (EPA) Office of Solid Waste staled at the September 2007 Air & Waste Management ...

  • Adsorption kinetics and diffusion of Saxitoxins on granular-activated carbon: influence of pore size distribution

    Saxitoxin (STX) is the most toxic non-protein substance known. STX-producing cyanobacteria have been identified in most continents and are being detected more widely because of global warming, threatening human drinking water supplies worldwide. Removal of these components can be accomplished by adsorption on granular-activated carbon (GAC) but little is yet known about the kinetics of the ...


    By IWA Publishing

  • Aeolian dust in sediment: a re-examination of methods for identification and dispersal assessed by diffuse reflectance spectrophotometry

    Analyses of aeolian sediments present two main challenges: (1) when aerosol particles are collected on atmospheric filters, only a small amount of aeolian material is normally present, and (2) in these and other samples, the aeolian sediment is typically mixed with other types of particles and the aeolian material often makes up only a small percentage of the total sample. Diffuse Reflectance ...


    By Inderscience Publishers

  • Monitoring and assessing heavy metals in topsoils as potential diffuse pollutants in the Pyeongchang River Basin, Korea

    Topsoils, mainly from crop fields, orchards, forests, and barns around the Pyeongchang River, were collected to investigate their heavy metal concentrations. Pollution load index, ecological risk index, and enrichment factor were applied to assess levels of heavy metal contamination for topsoils. The concentrations of cadmium (Cd) (1.7 mg/kg) and chromium (Cr) (4.1 mg/kg) exceeded the troublesome ...


    By IWA Publishing

  • Diffusion flux of phosphorus nutrients at the sediment–water interface of the Ulansuhai Lake in northern China

    Overlying water and sediment samples were collected from 11 locations in Ulansuhai Lake in June of 2012 to determine the concentration of dissolved inorganic phosphorus (DIP) in the interstitial water, overlying water and sediment and to estimate the diffusion flux of DIP at the sediment–water interface. The DIP levels in overlying water were 0.004–0.185 mg/L (average = 0.062 mg/L), while they ...


    By IWA Publishing

Need help finding the right suppliers? Try XPRT Sourcing. Let the XPRTs do the work for you