783620H / 1013 5. MENU COMMANDS
are presented: OK or ERR, and numeric values. The SOH parameters return either OK or ERR.
If the state is OK, the parameter stayed within the set limits during the spectrum acquisition.
If the parameter varied from the nominal value by more than the allowed limit, the ERR is set until cleared by the program. The numeric values are displayed in the units reported by the
DSPEC-50. Security, Detector temperature, and Live detector temperature are available only for SMART-1 detectors. For non-SMART-1 detectors, they display N/A.
Detector State of Health
Returns OK or an error message describing a problem with detector power or bias.
+24 volts
This is the current value of the +24 volt supply.
+12 volts
This is the current value of the +12 volt supply.
!12 volts
This is the current value of the
!12 volt supply.
Fig. 84. DSPEC-50 Status Tab.
!24 volts
This is the current value of the
!24 volt supply.
High Voltage
This is the current value of the high voltage bias supply.
Note that, as of this release, the Detector temperature and Live detector temperature monitors are listed, but return only N/A.
Presets
Figure 85 shows the Presets tab. MDA presets are shown on a separate tab.
The presets can only be set on an MCB that is not acquiring data (during acquisition the preset field backgrounds are inactive [gray]). You can use any or all of the presets at one time. To disable a preset, enter a value of zero. If you disable all of the presets, data acquisition will continue until manually stopped.
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v7 (A66-BW) 783620H / 1013
When more than one preset is enabled (set to a non-zero value), the first condition met during the acquisition causes the MCB to stop.
This can be useful when you are analyzing samples of widely varying activity and do not know the general activity before counting.
For example, the Live Time preset can be set so that sufficient counts can be obtained for proper calculation of the activity in the sample with the least activity. But if the sample contains a large amount of this or another nuclide, the dead
Fig. 85. DSPEC-50 Presets Tab.
time could be high, resulting in a long counting time for the sample. If you set the ROI Peak preset in addition to the Live Time preset, the low-level samples will be counted to the desired fixed live time while the very active samples will be counted for the ROI peak count. In this circumstance, the ROI Peak preset can be viewed as a “safety valve.”
The values of all presets for the currently selected MCB are shown on the Status Sidebar. These values do not change as new values are entered on the Presets tab; the changes take place only when you Close the Properties dialog.
Enter the Real Time and Live Time presets in units of seconds and fractions of a second. These values are stored internally with a resolution of 20 milliseconds (ms) since the MCB clock increments by 20 ms. Real time means elapsed time or clock time. Live time refers to the amount of time that the MCB is available to accept another pulse (i.e., is not busy), and is equal to the real time minus the dead time (the time the MCB is not available).
Enter the ROI Peak count preset value in counts. With this preset condition, the MCB stops counting when any ROI channel reaches this value unless there are no ROIs marked in the MCB, in which case that MCB continues counting until the count is manually stopped.
Enter the ROI Integral preset value in counts. With this preset condition, the MCB stops counting when the sum of all counts in all ROI channels (regardless of the number of ROIs) reaches this value. This has no function if no ROIs are marked in the MCB.
The Uncertainty preset stops acquisition when the statistical or counting uncertainty of a userselected net peak reaches the value you have entered. Enter the Preset in % value as percent
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