Spectrum Analyzer Test Limitations

Based on data for the spectrum analyzer device, a substrate correction may not be needed for some substrates, but based on laboratory data, it may be needed for other substrates, such as steel. From the limited data available, the true lead concentration is expected to be within 0.7 mg/cm of the experimental value 95% of the time for measurements over wood and plaster when the precision of replicate measurements over the same substrate is no poorer than 0.1 mgkm.  

Correcting Irregular Geometric Shapes with PXRF Devices 

Irregular shapes of house components have not formerly been addressed, but it is recommended that measurement of any irregular shape, such as a round post, molding, etc., be especially addressed, since the flat-shaped measurement will obviously produce a different measurement. Measuring irregularly shaped wood and metal surfaces is discussed by Gooch (1991) in a Georgia Tech Research Institute report on lead paint abatement. 

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Before analyzing the results of these, or similar, thermochemical cycles, the assumptions which have been made must be critically examined. Since the cycles are tested for different surface coverages, it is assumed first that the Q-0 curves represent correctly, in all cases, the distribution of reactive sites—the energy spectrum—on the surface of the adsorbent. This point has been discussed in the preceding section (Section VII.A). It is assumed moreover that, for instance, the first doses of carbon monoxide (8 = 0) interact with oxygen species adsorbed on the most reactive surface sites (0 = 0). This assumption, which is certainly not acceptable in all cases, ought to be verified directly. This may be achieved in separate experiments by adsorbing limited amounts of the different reactants in the same se-... 

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