Process gas sampling

Process-Gas Sampling In samphng process gases either to... 

Mass Spectrometer. The mass spectrometer is the principal analytical tool of direct process control for the estimation of tritium. Gas samples are taken from several process points and analy2ed rapidly and continually to ensure proper operation of the system. Mass spectrometry is particularly useful in the detection of diatomic hydrogen species such as HD, HT, and DT. Mass spectrometric detection of helium-3 formed by radioactive decay of tritium is still another way to detect low levels of tritium (65). Accelerator mass spectroscopy (ams) has also been used for the detection of tritium and carbon-14 at extremely low levels. The principal appHcation of ams as of this writing has been in archeology and the geosciences, but this technique is expected to faciUtate the use of tritium in biomedical research, various clinical appHcations, and in environmental investigations (66). 

Fay and Lewis (1977) used spherical gas samples inside soap bubbles whose volumes ranged from 20 to 190 cm. Typically, a sphere was ignited with resistance wire, and the combustion process was then filmed with a high-speed camera. The fireball s maximum height and diameter, as well as the time needed to complete combustion, were evaluated. The fireball s thermal radiation was sensed by a radiation detector. Figure 6.3 relates fireball burning time and size to initial propane... 

Diffusion is a relatively slow process a sample of gas introduced at one location may take an hour or more to distribute itself uniformly throughout a room. At first glance this seems surprising, since as we saw in Example 5.10 gas molecules are moving very rapidly. However,... 

Calculate the work for each of the following processes beginning with a gas sample in a piston assembly with... 

Patterson suffered the first of many severe asthmatic attacks after collecting acidic gas samples from a Hawaiian volcano in 1983. The steroids he took for the asthma exacerbated his inherited osteoporosis, and his frame shrank nine inches to five foot seven. He applied twice for funds to create a line of lead-free rats to study biological processes in uncontaminated mammals. After both applications were rejected, he frequently became depressed. 

As the process of the gas sampling and the solvent extraction has to be carried out quickly (within 3 min at the longest) for the direct measurement of the Rn-220 decay, accurate measurements of the gas volume and the temperature are not possible. Therefore, the coexisting Rn-222 is used as a tracer for the determination of the gas volume and the solvent extraction efficiency that is, another gas... 

A second system, the removal of volatiles by vacuum, can be set up in two ways either as a flow-through or as a batch process. As a flow-through process, the sample is drawn continuously through the system, and the gases taken off by the vacuum pass through a sampling loop. Periodically, the material in the loop is injected into the gas chromatograph. In this manner it is possible to derive almost continuous profiles of volatile hydrocarbon concentrations [19]. 

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