Difference between revisions of "Measurements and Calculations (Introduction to Radiochemistry)"
(→Background) 

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Counting speed:<br>  Counting speed:<br>  
−  <math>\frac{N_{bck}}{t_{bck}}=\underline{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\mbox{cps}</math>  +  <math>\frac{N_{bck}}{t_{bck}}=\underline{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\mbox{cps}</math> <br> 
Standard deviation:<br>  Standard deviation:<br>  
<math>\frac{\sqrt{N_{bck}}}{t_{bck}}=\underline{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\mbox{cps}</math>  <math>\frac{\sqrt{N_{bck}}}{t_{bck}}=\underline{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\mbox{cps}</math>  
−  
==== Counting Efficiency ====  ==== Counting Efficiency ==== 
Revision as of 08:03, 3 July 2012
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Which detector did you use?
Contents
Background
Note down the values from the background counting you started the day before.
Counting number:
Counting time:
Counting speed:
Standard deviation:
Counting Efficiency
Do a one minute count on every shelf. Use these measurements to calculate the countingefficiency of the GMdetector in %, for ^{234m}Pa. The activity of the sample can be calculated from the amount of UO_{3} used.

Counting number for each shelf (CPM)  Counting Efficency 
1  

2  

3  

4  

Twenty Measurements with Constant Distance from the Source
Do twenty measurements lasting for one minute with the source in the same position. Calculate the standard deviation and complete the table:
Nr  
1  


2  


3  


4  


5  


6  


7  


8  


9  


10  


11  


12  


13  


14  


15  


16  


17  


18  


19  


20  


SUM:  
SUM:  
Mean value of the counting numbers
The squere of the mean value
Standard deviation
Discuss the results from and ?
Assessment of the Results
Write down the given measurements and calculate how many % of the countings that are outside of the intervals <NS_{N},N+S_{N} and <N2S_{N},N+2S_{N}>:




Is there, in your opinion, to many single measurements outside of the given areas? Give a answer based on statistical normal distribution.