Panasonic PT-DZ12000U Operating Instructions Manual page 76

The sam e form ula in Sv/h at 30 cm is given by
1.6TBqEN,
where TBq is the num ber of terabecquels.
Sv/hr at 30 cm =1.6TBqEN
where; TBq
E = photon energy in MeV
N = abundance of that photon expressed as a
decim al
exam ple:
Change the % to decim als for the equation.
W e need to sum the photon energy tim es their
abundances.
Sv/hr at 30 cm = 1.6 x 3 x (1.173x1 + 1.332x1)
Sv/hr at 30 cm = 4.8 x (2.5) = 12 Sv/hr
12 Sv/hr is 1,200 Rem /hr
In an exam ple of the use of the Inverse Square Rule
a 100 Curie Co-60 source could be used. The 6CEN
calculation for that source yields 1,500 Rem /hr at 1
foot distance. 100 Curies is 3.7 TBq. The two
m ethods yield results that are the sam e within 2%.
1.6TBqEN
= quantity of radioactive m aterial
A 3 TBq Co-60 source which has gam m a
energies and abundances of 1.173 MeV at
100% and 1.332 MeV at 100%.
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