PCM-2 Manual.pdf - Voss Associates

Background Averages
Alpha and beta channel background count rates for all active detectors are
displayed. These are the values currently being used by the PCM-2 for internal
calculations, computed with the current weighting factors. Counts are updated
periodically in this display. Count rates are shown in the units selected in the
instrument parameters menu (CPM or CPS). Pressing the F2 key enables or
disables geometry correction of background data. When correction is applied, the
raw count data is multiplied by a detector geometry correction factor. This
permits easy comparisons of count rates from detectors of differing sizes.
Detector Performance Data
The user may view the current day files for transactions, status, changes, and
source check results. Day files are explained in detail in Section 5.
Hand Probe Readings
Depending upon system operating mode, this screen shows either count times or
RDA values calculated for each detector channel at the present background levels
and operating parameters. The display is sorted from highest (worst) to lowest
(best) to provide a quick assessment of the range of values and to identify which
detectors are most likely to cause problems if background levels increase.
Gross Count Rates
Stored background and current real-time count rates are shown for the optional
hand frisking probe (if installed). Background data is accumulated whenever the
probe is in its holder; net count rates are therefore displayed only when the probe
is in use. The hand probe alarm setpoints for the alpha and beta channels are also
displayed
The last count rate from each detector channel is shown, without any averaging or
weighting factors applied. This screen is particularly useful for observing the
response of detectors to a source.
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PCM2.MAN/ Rev A/April 1995