Understanding NRT- Reading 1- 2 of 2- Radiogaphic Testing A
Understanding nrt reading 1- 2 of 2- radiogaphic testing a
Understanding nrt reading 1- 2 of 2- radiogaphic testing a
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Activity <strong>of</strong> Co-60<br />
Corresponding to its half-life the radioactive activity <strong>of</strong> one gram <strong>of</strong> 60 Co is 44<br />
TBq (about 1100 curies). The absorbed dose constant is related to the decay<br />
energy and time. For 60 Co it is equal to 0.35 mSv/(GBq h) at one meter from<br />
the source. This allows calculation <strong>of</strong> the equivalent dose, which depends on<br />
distance and activity.<br />
Example: a 60 Co source with an activity <strong>of</strong> 2.8 GBq, which is equivalent to 60<br />
µg <strong>of</strong> pure 60 Co, generates a dose <strong>of</strong> 1 mSv at one meter distance within one<br />
hour. The swallowing <strong>of</strong> 60 Co reduces the distance to a few millimeters, and<br />
the same dose is achieved within seconds.<br />
Test sources, such as those used for school experiments, have an activity <strong>of</strong><br />
Change language