Ludlum Measurements 334A, Руководство по эксплуатации

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Model 334A Operations Manual
Ludlum Measurements, Inc 14 January 2021
NOTE: After a few hours, if the 3 peaks are not all visible, the Offset needs to be increased
by 8, 16, or 24 channels to shift the peaks further left. Click Reset Spectrum and run the
unit again for several hours to accumulate another spectrum .
Lining Up the Daughter Radon Peaks
After all three peaks of the Alpha radon spectrum are clearly visible on the screen; the radon
daughter peaks can be calibrated. Line up each of the red lines with their respective peak
location by dragging the lines across the screen until they line up with the top of the peak.
Another number will appear while the line is being dragged that indicates the number of
counts per channel. Release the line on the channel with the highest counts.
Calibrating the Isotope-of-Interest
The isotope(s)-of-interest also needs to be energy calibrated at this point. Remove the filter
and leave the detector exposed. Using an appropriate source holder, to provide repeatable
geometry, place the desired isotope-of-interest calibration source in the detector recess so
that the source face is the same distance from the detector as a filter would be . Leave it there as a well-
defined peak becomes visible on the screen. Remove the source before the peak becomes
too large.
Then, drag the remaining red line and align it with the peak location. Repeat this procedure
if necessary with a second source corresponding to the alternate isotope-of-interest.
Alternatively , use the Isotope of Interest Channel Calculator (found on the CD) to
determine the peak location, without a source.