PTW DIAMENTOR E2 - Page 21

DIAMENTOR E2
Calibration
D651.131.00/05 en 21
− Note down the reading M
Reference
shown on the
diagnostic dosemeter.
− Note down the dose area product reading
shown on the DIAMENTOR E2 (DAP
Measured
).
− Calculate the dose area product
DAP
Calc
= M
Reference
x A where A is the field size.
− Repeat the measurement 3 times, noting down
the results.
Fluoroscopy (undercouch tube)
− Place the measurement phantom without de-
tector on the patient couch (phantom at the bot-
tom).
− Start fluoroscopy and determine the field size A
in the plane of the phantom by means of the
phantom depicted on the screen.
− Turn the measurement stand and put the detec-
tor and its holder in place (phantom at the top,
detector at the bottom).
− Start another fluoroscopy for approx.
30 seconds.
− Note down the reading M
Reference
shown on the
diagnostic dosemeter.
− Note down the dose area product reading
shown on the DIAMENTOR E2 (DAP
Measured
).
− Calculate the dose area product
DAP
Calc
= M
Reference
x A where A is the field size.
− Repeat the measurement 3 times, noting down
the results.
Fluoroscopy (overcouch tube)
− Place the measurement stand without detector
on the patient couch (phantom at the top).
− Start the fluoroscopy and determine the field
size in the plane of the phantom by means of
the phantom depicted on the screen.
− Turn the measurement stand and put the detec-
tor and its holder in place (phantom at the bot-
tom, detector at the top).
− Start another fluoroscopy for approx.
30 seconds.
− Note down the reading M
Reference
shown on the
diagnostic dosemeter.
− Note down the dose area product reading
shown on the DIAMENTOR E2 (DAP
Measured
).
− Calculate the dose area product
DAP
Calc
= M
Reference
x A where A is the field size.
− Repeat the measurement 3 times, noting down
the results.
Calculating the New Chamber Calibration Factor
− Calculate the mean value of (dose area prod-
uct) DAP
Calc
.
−
Calculate the mean value of (dose area prod-
uct) DAP
Measured
.
− Calculate the new chamber calibration factor
K
new
, using the mean values and the old cham-
ber calibration factor:
K
new
=
old
Measured
Calc
K
DAP
DAP
⋅
Saving the New Chamber Calibration Factor
Enter the new chamber calibration factor as de-
scribed in section
4.5.