CIANFLONE 2501XBT, Инструкция по эксплуатации и безопасности

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5. OPERATING THE PORTASPEC
5-5
Portaspec to the sample will cause inaccuracies in the results. Maximum
sample distance from bottom of x-ray port should not exceed 0.05 inches.
Cianflone Scientific has available, and can provide sample preparation and
presentation equipment to suit your needs.
5.5. Qualitative and Quantitative Analysis
Qualitative analysis is the determination of what elements are present in a sample.
Specimen preparation is less critical with this analysis method.
In qualitative analysis, the Portaspec can be made to scan through the two-theta
angle range of interest. The elements present are identified by the increase in
counts observed. Intensities at element peaks can be used to determine if an
element is present, but not quantify the amount. However, the approximate
concentration of an element can be estimated when compared to standards.
A qualitative analysis can be performed using the Model 2501XBT. From the Setup
mode u
nder the Scaler tab, press the “Read Count Rate” button. Set the Element
Dial to a low angle, press the “Read Count Rate” button. Now scan through the
two-theta range slowly while observing the reading in the Count Rate window. As
you scan past an element present in a sample, an increase in the count rate will be
noticed.
Quantitative analysis is the determination of the amount of an element present in a
sample using one of the analysis methods described in detail in the Portaspec
Software Instructions. With the use of calibration standards, a comparison of analyte
intensities verses concentration, thickness or weight can be used to create a
regression or calibration model. These standards with known or proven
concentrations should number at least three and more, for greater modeling
accuracy. The more standards used, the easier it is to recognize a non-linear trend
in the standardization process. Although a calibration curve need not be linear to be
useful, short segments of non-linear curves, if bracketed by standards, can be
assumed to be linear.
Refer to the Portaspec Analysis and Control software for detailed methods on
quantitative analysis.