296-297 / 3107
- put ionisation chamber in H
2
O in reference conditions
- irradiate with photon beam
reading M
Q
(Q = quality of your beam)
D
w,Q
= M
Q
∙N
D,w,Co
∙k
Q,Co
∙
k
i
N
: chamber calibration factor, delivered by standards
calculate dose to H
2
O in absence chamber:
How to measure absorbed dose in water:
k
Q,Co
: correction of N
D,w,Co
for use in quality Q instead of Co
(depends on chamber type and beam quality Q)
D,w,Co
laboratory
(N
D,w,Co
specific for each individual chamber)
corrections for deviations from reference conditions
other than Q, e.g. temperature, air pressure, recombination, etc.
k
i
:
i