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8.2.4. Status...
The QA status for the currently selected Detector is displayed as shown in Fig. 285. Click OK to close the dialog.
Fig. 285. Showing Status of QA Measurements for a Detector.
8.2.5. Control Charts...
The Control Chart... functions display the data stored in the QA database as a control chart. The displayed data can be scrolled backward or forward across the screen so that all collected data can be viewed. A typical chart is shown in
Fig. 286. The short dashed lines represent the warning limits and the long dashed lines represent the acceptance threshold limits. Note that if you call this command before any QA settings are established in the GammaVision QA database, you will receive an error message. Acknowledge the message and set up your detectors in the QA database.
Fig. 286. Control Chart Example.
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Figure 287 shows the control chart File menu, which contains the Print Graph command for printing the current graph on the current printer; a standard Windows Print Setup... command for selecting the printer and its setup features, such as landscape vs. portrait layout, paper size, number of copies, and device control options; the Exit command for closing the QA Chart
Program (this duplicates the dialog’s upper-right Close box); and an About box providing version information about the chart program.
Choose the chart time period (Week, Month, or Quarter) from the Scale menu (Fig. 288).
The Plot Variable menu (Fig. 289) contains functions for selecting Activity, Peak Energy,
Peak Width @ Half Max, Peak Width @ Tenth Max, or Background.
Fig. 287. QA Chart File
Menu.
Fig. 288.
Scale Menu.
The Detector menu item opens the list of Detectors for which background and sample measurements have been made (Fig. 290). Select a Detector for this control chart and click OK.
Offline processing of the QA data-base (including detailed trend analyses) can be done outside of
GammaVision. The database format used is welldocumented and compatible with a number of popular software products including Microsoft
Access.
NOTE
We strongly recommend that you back up any GammaVision database files before performing manipulations on them outside of GammaVision.
Fig. 289. Plot Variable
Menu.
Fig. 290. Detector Pick List.
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The Options menu (Fig. 291) includes an Always On Top command, which keeps the QA window on top of all other windows, no matter which window (in GammaVision or any other program) might be active.
Fig. 291. QA Chart
File Menu.
The Fixed Vertical Scale command adds flexibility in displaying control charts both onscreen and on printouts, for comparison with other charts.
! Fixed Vertical Scale Off (no check mark) — In this mode, the vertical scale of the graph is adjusted so that all points are shown to scale. All points are black. If one or more data points are substantially out of range, the graph may be quite compressed vertically.
! Fixed Vertical Scale On (check mark) — In this mode, the vertical scale of the graph is set to show the upper and lower alarm limits as full scale. The data points within the alarm limits are colored black. Out-of-range points are displayed in red at the lower or upper limits of the graph, at the proper horizontal coordinate. The out-of-range points are printed as a question mark ( ? ).
To switch between the two display modes, click the menu item to mark it with a checkmark or unmark it.
Figures 292 through 295 show the screen and printout for a QA data set with Fixed Vertical
Scale on, then off. Compare the location of the points that exceed alarm limits in Figs. 292 and 293 to the location of the question marks in Figs. 294 and 295.
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Fig. 292. Control Chart On Screen with Fixed Vertical Scale On.
8. QUALITY ASSURANCE
Fig. 293. Printout of Control Chart with Fixed Vertical Scale On.
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Fig. 294. Control Chart On Screen with Fixed Vertical Scale Off.
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Fig. 295. Printout of Control Chart with Fixed Vertical Scale Off.
