Capintec CAPTUS 600, Руководство пользователя, Страница: 138 / 218

CAPINTEC, INC. CAPTUS
®
600
in dpm , not cpm. This means only peaks for which a Conversion Factor (CF) is entered in
memory will be compared to this trigger level.
Counting Time determines how long the CAPTUS
®
600 will count during a Wipe Test.
Input the desired Trigger Level and Counting Time.
Press
F4 [OK] when the data is correct. This will store the data for this area in memory. The
Trigger Level / Count Time Area Select Screen (Figure 12-7) will re-appear.
When finished setting the Trigger Levels, press
0 to return to the Wipe and MCA Setup menu
(Figure 12-3).
GENERIC CONVERSION FACTORS
Generic Conversion Factors is the next item that should be set up. Generic CF is used as a
general-purpose measure of activity. It does not correspond to any particular isotope. For this
reason, it should only be used as a check and not as a measure of activity of any particular
isotope.
The Generic CF is multiplied by the cpm measured for a Region of Interest consisting of all
256 channels of the CAPTUS
®
600 Pulse Height Analyzer (PHA) after a wipe is measured.
Since Wipe Tests are only performed on the 400 and 1600 keV full-scale range, it is
necessary to set up CFs for these ranges only. A CF should be chosen so that for a wipe that
is equivalent to background, the results for the generic CF don't exceed the Trigger Levels
set up in the previous section.
To set up Generic Conversion Factors, from the
Wipe and MCA Setup menu, press 4 to
select GENERIC CONVERSION FACTORS . Figure 12-9 will appear.
13:06
OK
400 keV CONVERSION FACTOR :>2.0
1600 keV CONVERSION FACTOR : 2.0
DONE P
GENERIC CONVERSION
Figure 12-9
If Generic Conversion Factors have never been entered, the default values of 2.0 will be
displayed. Otherwise, the last entered values will be displayed.
12-6 WIPE TEST SETUP November 07