Sampling train

Automated analyzers may be used for continuous monitoring of ambient poUutants and EPA has developed continuous procedures (23) as alternatives to the referenced methods. Eor source sampling, EPA has specified extractive sampling trains and analytical methods for poUutants such as SO2 and SO [7446-11-9] sulfuric acid [7664-93-9] mists, NO, mercury [7439-97-6], beryUium [7440-41-7], vinyl chloride, and VOCs (volatile organic compounds). Some EPA New Source Performance Standards requite continuous monitors on specified sources. 

Figure 9 shows the sampling train for sulfuric acid mist collection (13). The first impinger contains 80 wt % isopropyl alcohol and the second and third contain 3 wt % H2O2. The first impinger and filter retain the acid mist and SO the next two retain the SO2. After sampling, the filter is added to the contents of the first impinger and the total acid is titrated and reported as sulfuric acid. 

ISO International Organization for Standardization VO ST Volatile organic sampling train... 

SW-846, is used to measure emissions of semivolatile principal organic constituents. Method 0010 is designed to determine destruction and removal efficiency (DRE) of POHCs from incineration systems. The method involves a modification of the EPA Method 5 sampling train and may be used to determine particulate emission rates from stationary sources. The method is applied to semivolatile compounds, including polychlorinated biphenyls (PCBs), chlorinated dibenzodioxins and dibenzofurans, polycyclic organic matter, and other semivolatile organic compounds. 

Gaseous and particulate pollutants are withdrawn isoldnetically from an emission source and collected in a multicomponent sampling train. Principal components of the train include a high-efficiency glass- or quartz-fiber filter and a packed bed of porous polymeric adsorbent resin (typically XAD-2 or polyurethane foam for PCBs). The filter is used to collect organic-laden particulate materials and the porous polymeric resin to adsorb semivolatile organic species (com-... 

Sounds with a boiling point above 100° C). Figure 25-42 presents an lustration of the Method 0010 sampling train. Comprehensive chemical analyses, using a variety of applicable analytical methodologies, are conducted to determine the identity and concentration or the organic materials. 

In the sampling train itself, the gas flow must be measured to determine the sample volume. Parhculates and gases are measured as micrograms per cubic meter. In either case, determination of the fraction requires that the gas volume be measured for the term in the denominator. Some sample trains contain built-in flow-indicahng devices such as orifice meters, roto-meters, or gas meters. These devices require calibration to assure that they read accurately at the time of the test and under test conditions. 

To determine the volume through the sampling train, a positive displacement system can be used. A known volume of water is displaced by gas... 

Standard sampling trains are specified for some tests. One of these standards is the system specified for large, stationary combustion sources (4). This train was designed for sampling combustion sources and should not be selected over a simpler sampling train when sampling noncombustion sources such as low-temperature effluents from cyclones, baghouses, filters, etc. (5). 

Before taking the sample train to the test site, it is wise to prepare the operating curves for the particular job. With most factory-assembled trains, these curves are a part of the package. If a sampling train is assembled from components, the curves must be developed. The type of curves will vary from source to source and from train to train. Examples of useful operating curves include (1) velocity versus velocity pressure at various temperatures (6), (2) probe tip velocity versus flowmeter readings at various temperatures, and (3) flowmeter calibration curves of flow versus pressure drop. It is much easier to take an operaHng point from a previously prepared curve than to take out a calculator and pad to make the calculahons at the... 

Modern transducers and microprocessors have been used successfully to automate particulate sampling trains in order to eliminate the operating curves and manual adjustments (7). The automated samplers adjust continuously to maintain isokinetic conditions. In addition, the microprocessor continuously calculates and displays both instantaneous sampling conditions and the total sample volume collected at any given moment. The use of the automated system with the microprocessor, therefore, eliminates both operator and calculation errors. 

When a sampling train requires an unusual combination of sampling media (e.g., glass fiber filter proceeding impinger), the same media/devices should be in line during calibration. 

Soil vapor probe and sampling train (Nadeau, 1985). 

Gas velocity is measured over an aperture in the heated zone of the sampling train, at a temperature of 110 °C, to remove the moisture by heating. Determine the gas velocity at the sampling nozzle if the measured velocity is 28 m s for the sampling diameter used. The water concentration determined from the condensate is 75 g m" (n). 

Sampling Train The sample is extracted through a sampling train, which consists of... 

Area samples Samples taken by placing the sampling train in a fixed location m the workplace. 

Sampling train The assembly of sample medium in its holder, with connecting tubing and sample pump. 

The mercury analyses were conducted using a Coleman Instruments mercury analyser (MAS-50) equipped with a recorder. The aqueous sample solution was contained in a 250 ml Pyrex glass bubbler placed at one end of a sampling train employing nitrogen as the purging and carrier gas. A schematic diagram of the entire system is shown in Fig. 5.12. 

EPA. 1994i. Method 0030. Volatile organic sampling train. Method Status Table SW-846, third edition updates I, II, IIA and IIB. U. S. Environmental Protection Agency. 

Extraction of semivolatile analytes collected using modified Method 5 (Method 0010) sampling train Accelerated solvent extraction (ASE) (3545A in update IVB) Ultrasonic extraction... 

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