Evaluate Results

The spectra returned from a search are displayed in the Search Results window.  As a result of a search, the spectra and their titles will be displayed in the upper right (Overlay) panel. A list of the spectra that satisfied the search criteria appear in the upper left (Spectrum List).  The spectra displayed are checked in this list. Several of the EDS utilities found on the X-ray Spectrum Database window are repeated on the search results window and several more have been added. Pan, zoom, auto vertical scale, vertical expansion, and KLM Markers are the same. The degree of spectra overlap is selected with the Overlap slider. There are 2 buttons for selecting log and square root displays, or if neither is selected, the display is linear. Overall, the square root display offers the best display for purposes of spectral comparisons. An additional group of buttons appear when a cursor is present, representing a "scaled" output. This is also extremely useful. All spectra are dynamically scaled at the cursor position, which can be moved by 2 of the buttons. Another pair of buttons will move the cursor to the next peak above or below the current cursor position, and the 3rd pair move the cursor to the 1st or last peak in the spectrum. The center button turns the scaled display on and off. The cursor can also be moved with the use of the arrow keys. There is feedback letting you know the display mode (log. square root or none), normalization mode (Scaled, Normalized, or none), the number of spectra checked and overlapped, and the cps in the highest peak of the spectrum being analyzed.

An individual spectrum can be accessed from this window. Highlight a spectrum title in the Spectrum List (left click), then right click the selected title to produce a drop-down menu. Go to Spectrum will display the selected spectrum in the Main Spectrum Database window (double-clicking the spectrum title will also do the same thing). From the same menu, Spectrum Info will display a window providing basic information about the selected spectrum. Check All simply checks all of the spectra in the Spectrum List, causing them all to be overlaid (sometimes making it difficult to determine much or anything), and Uncheck All deselects all spectra.

Spectra titles are displayed at the bottom of the display (Summary Panel) according to Degree of Fit. The Degree of Fit ranges from 0 to 100, 100 being a perfect fit. Also included is the Group Membership, whose values cover the same range of 0 to 100. Group Membership generally displays similar values for spectra from like materials. The Material column indicates the group or classification of the materials that are close to the unknown. If enough of the materials are from the same category, the unknown is said to be consistent with that material. In the example above, the unknown is extremely close to spectra from Finn, Hungary lighter flint particles. And even other lighter flints though not as close, are from the same classification and thus the Group Membership is also high.

The use of the Square Root Display, Scaled Display, and variable overlap, make comparisons much easier to evaluate. And by moving the cursor through peaks the similarities and differences stand out even more. It is obvious that the main difference between the unknown particles and particles from Finn, Hungary #2 lighter flints is that the latter have significant amounts of Lanthanum, causing a significant break in the Degree of Fit (~67), even though the Group Membership remains high.