Sources correction factor

Procedures for determining the spectral responslvlty or correction factors In equation 2 are based on radiance or Irradlance standards, calibrated source-monochromator combinations, and an accepted standard. The easiest measurement procedure for determining corrected emission spectra Is to use a well-characterized standard and obtain an Instrumental response function, as described by equation 3 (17). In this case, quinine sulfate dlhydrate has been extensively studied and Issued as a National Bureau of Standards (NBS) Standard Reference Material (SRM). 

Debye-Walter factors of the source and the absorber, respectively 5r, experimental correction factor, which is constant as function of the mercury concentration), experimental line width F/2 and isomer shift 5 as a function of the Hg content of the PtHg alloy (taken from [482])... 

Figure 9-2 Viscosity correction factor Kv for conventional reliefs in liquid service. Source API RP 520, Recommended Practice for the Sizing, Selection, and Installation of Pressure-Relieving Systems in Refineries, 6th ed. (1993), p. 35. Used by permission of the American Petroleum Institute, Washington, DC.

Estimating the amount of a metabolite when an authentic reference standard is not available is still a challenge. Yu et al.191 described a procedure that uses the results of an in vitro metabolite identification based on a test compound that produces 14C-labelled metabolites essentially the 14C-labelled metabolites are used to provide a correction factor for the MS response when assaying samples that contain the same metabolite in a study that did not use the 14C-labelled test compound. Flop192 described another novel approach for metabolite quantitation based on the observation that the MS responses for most compounds are very similar to responses from nanospray ESI. Valaskovic et al.193 also reported equimolar MS responses for multiple compounds when the flow rate to the nanospray ESI source was set to about 10 nl/min. It is too soon to know whether these intriguing findings can be readily applied to discovery metabolite identification studies. 

Determinate errors may also arise from unavoidable sources. An error that is known to have occurred but was unavoidable is called a bias. Such an error occurs each time a procedure is executed, and thus its effect is usually known and a correction factor can be applied. 

The application of SIMS, SNMS, SSMS and GDMS in quantitative trace analysis for conducting bulk material is restricted to matrices where standard reference materials (SRMs) are available. For quantification purposes, the well characterized multi-element SRMs (e.g., from NIST) are useful. In Table 9.5 the results of the analysis by SNMS and the RSCs (relative sensitivity coefficients) for different elements in a low alloy steel standard (NBS 467) are compared with those of SSMS. Both solid-state mass spectrometric techniques with high vacuum ion sources allow the determination of light non-metals such as C, N, and P in steel, and the RSCs for the elements measured vary from 0.5 to 3 (except C). RSCs are applied as a correction factor in the analytical method used to obtain... 

In the weak coupling limit, as is the case for most molecular systems, each molecule can be treated as an independent source of nonrlinear optical effects. Then the macroscopic susceptibilities X are derived from the microscopic nonlinearities 3 and Y by simple orientationally-averaged site sums using appropriate local field correction factors which relate the applied field to the local field at the molecular site. Therefore (1,3)... 

Convert measured SD and/or SI to paleo-C02 levels, and calculate paleoelevation using either (preferably) leaf material from the same taxon from a contemporaneous low elevation flora, or sea-level C02 reconstructions from other sources. Use C02 correction factor for stomatal density if necessary. 

Correction Factors Considered by Simamora and Yalkowsky. Source Simamora and Yalkowsky, 1994. (Copyrighted by the American Chemical Society Reproduced with permission.)... 

The dependence of the correction factor on the total count rate in the spectrum in the measurements with the p-type detector is presented in Figs. 3 and 4. Figure 3 shows a comparison of the dependences measured with the 241Am source for measurements with the base-line restorer threshold set to AUTO and VAR. Figure 4 presents the dependencies of the correction factors when 60Co was used as the second source. In Fig. 5 the dependence of the correction factor on the total count rate measured with the Ge(Li) detector is presented. The dependencies of the correction factors on the total count rate measured on the spectrometer with the Ortec 573 amplifier are presented in Figs. 6 and 7, with Fig. 6 pre-... 

Fig. 3 Correction factor for the 662 keV peak as a function of the total count rate measured on a p-type detector with an 241 Am source with the base-line restorer threshold set to AUTO (full circles) and with the base-line restorer threshold set to VAR (open...

Fig. 7 Correction factors for the x-ray peak at 32 keV (a) and the correction factors for the 662 keV peak (b) as functions of the total count rate measured on a low-energy p-type detector with a 60Co source...

Figure 12-34. Correction factor versus L/D for two-phase flashing flow through pipes. (Source J. C. Leung and M. A. Grolmes, The Discharge of Two-Phase Flashing Flow in a Horizontal Duct, AlChE Journal, 33(3), p. 524, 1987.)...

The ionisation process does not reproduce, in the output of ions, the relative amount of gas at the source. By the use of reference gases, such as N2, the gauge sensitivity can be established and, by the use of appropriate correction factors, differing extents of ionisation can be accounted for. 

Figure 20.8 shows the resulting correction factors for H+ derived from the present simulations, including a magnetic field of 37 mT in the center part of the ion source, in comparison to the values published by Poll et al. [13] and Gluch et al. [34]. In contrast to [13] and based on the findings in [34] for each electron energy and each ion a characteristic discrimination... 

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