ISSN:0049-8246    

DOI:10.1002/xrs.1300090302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe use of the multiple linear regression program for the derivation of influence coefficients destroys the data bank in the Philips PW 1450/10 spectrometer computer and interrupts analysis. Consideration of the basis of α‐coefficients as applied to relatively dilute solutions leads to methods of avoiding the use of this program. Linear regression involving a single independent variable and simple algebraic expressions can be used to derive the coefficients. The requirements for converting α‐coefficients applicable to one solvent for use in a different solvent are desc

ISSN:0049-8246    

DOI:10.1002/xrs.1300090303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA computer control system for an electron probe microanalyser has been designed using CORAL‐66, a high level compiler language, for the control program and CAMAC modules for the instrument interface. The consequences of the choices made in the design are discussed. The performance of the system was measured by comparing the results from carrying out typical operations by hand and by computer control. The results showed an improvement in precision for general operation and analysis, a reduction in the time for analysis and an improvement in operator performance from using the control syste

ISSN:0049-8246    

DOI:10.1002/xrs.1300090304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe ways in which the usefulness of the electron probe X‐ray microanalyser is extended by computer control and the demands imposed on the computer operating system by a general purpose electron probe are discussed. Three main modes of operation are identified and a flexible operating system to meet the main requirements for these modes is described. Examples of the use of the system are given with particular emphasis on two applications which could not be tackled easily with a manually operated system: composition surveys over large areas of the sample and digital mapping technique

ISSN:0049-8246    

DOI:10.1002/xrs.1300090305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractFifty pairs of window/non‐window glasses, the samples in each pair being matched in refractive index to the fourth decimal place, have been analysed using energy‐dispersive X‐ray fluorescence spectrometry. The spectra, from 200μg fragments, were compared using a computer based multi‐dimensional data processing system. Forty‐three pairs of glasses were readily discriminated and forty‐nine pairs showed significant differences at about the 5% level. The spectral data for the 100 glass samples were then examined graphically for trends in the elemental levels between the window and non‐window glasses. This led to the construction of two linear combinations, namely the peak area ratio (to calcium) of iron with that of magnesium and the peak area of arsenic with refractive index. When plotted against each other these linear combinations and a selection rule allowed 95% of the glasses to be correc

ISSN:0049-8246    

DOI:10.1002/xrs.1300090306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA simple equation relating the intensity of characteristic X‐ray lines to their respective weight fractions has been obtained for a thick sample excited by an isotopic source. It follows from the equation that a single intense line in a standard sample suffices to generate calibration constants over a wide range of elements. Validity of this aproach has been demonstrated by the analysis of a standard soil sample using only the Fe Kα line for calibration. A procedure for correction of peak overlaps has been given using the Kβ/Kα ratios, modified by the matrix effects. The method is very useful for the analysis of soil samples and can be conveniently applied to other matr

ISSN:0049-8246    

DOI:10.1002/xrs.1300090307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA detailed study of energy‐dispersive X‐ray spectra is undertaken. Considerable attention is given to a method for a systematic and accurate description of the K and L spectra; a digital correction for the peak profile is evaluated. The following second order effects and spectral artefacts are investigated: radiative Auger transitions, spectral background components, Raman scattering of X‐rays, silicon escape, fluorescence of the detector materials, and sum

ISSN:0049-8246    

DOI:10.1002/xrs.1300090308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractEs wird eine quantitative Analysenmethode für geologische Proben (Silikate and Karbonate) mittels Röntgenmikrosonde beschrieben. Im Falle von Silikaten sind fur eine Totalanalyse mehr als 10 chemische Elemente simultan zu erfassen (Haupt‐und Nebenelemente). Zwei experimentelle Moglichkeiten sind realisierbar: (a) Automatischer Sequenzbetrieb mittels Kristallspekrometern; (b) Kombination WDS/EDS (wellenlangendispersives und energiedispersives System). Diese beiden Möglichkeiten werden diskutiert. Technische Angaben und apparativer Aufwand werden beschrieben. Es wird dargelegt, auf welche Weise eine hohe analytische Genauigkeit erreicht werden

ISSN:0049-8246    

DOI:10.1002/xrs.1300090309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractSmall amounts of particulate matter electrochemically extrated from super‐alloys were accurately analysed by X‐ray fluorescence spectrometry with pure element bulk standards. The extracts are less than a few hundred micrograms per square centimeter and are not homogeneous. They are approximated by a thin film on a filter substrate. The penetration of the particulates into the membrane filter on which they are mounted is negligible and no absorption correction for the filter is required. The spectral distribution of the X‐ray source used in the calculation was obtained from Kramer's formula with self‐absorption correction for the continuum and from measurements of the characteristic line. The intensity‐concentration algorithm is based on the fundamental parameter method; the calculation is simplified because no matrix correction is required if the relative intensities are less than or equal to 0.04. The method gives excellent results in chemical

ISSN:0049-8246    

DOI:10.1002/xrs.1300090310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe spectral photon distribution from X‐ray tubes operated at constant potential is compared to the distribution resulting from self rectification circuits. Kramers' equation is modified by calculating the average values of the photon flux during one period of voltage fluctuation and the results are used to transform Gilfrich and Birks' experimental tube spectra to those expected from a half‐wave rectification circuit. The effect of using both constant potential and sine wave potential, as well as constant potential with overlaid sine wave ripple, is discussed. Results are shown by using experimental data from Ag‐Au‐Cu alloys and ‘no standard’ methods (data evaluation without reference

ISSN:0049-8246    

DOI:10.1002/xrs.1300090311

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY