Doza DROZD Manuale d'uso - Pagina 9
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4.5 Procedure
4.5.1 External examination
Items to be checked during external examination:
-
proper completeness;
-
availability of operational documentation;
-
absence of defects which could affect the dosimeter's operation.
4.5.2 Testing
Testing of the dosimeter is carried out in accordance with 2.3.
4.5.3 Determination of basic relative measurement error of AEDR of gamma radiation
Determine the basic relative measurement error at levels of AEDR of gamma radiation 10
-1
and 900 μSv·h
.
Perform calibration as follows:
1) place the dosimeter on calibration installation with front panel towards the source and the
center of dosimeter's sensitive area located at the central axis of the gamma radiation beam at a
distance from the source corresponding to reference AEDR value 10 μSv·h
located 20 mm deep below the center of the circle at the dosimeter's front panel;
2) turn the dosimeter on in the measurement mode and press the "START" button;
3) expose dosimeter to radiation and measure AEDR taking readings from the LCD with
statistical uncertainty is less than 5 %;
4) perform at least three (i=3) measurements for this test point;
5) perform operations described in 1) – 4) for the second level of AEDR equal to 900 μSv·h
6) For each test point j calculate the basic relative error of AEDR
following formula
H
*
where
is the value of AEDR, reproduced by the calibration installation UPGD-2M-D, μSv·h
refj
H
*
is the arithmetic mean value of AEDR of gamma radiation calculated using three
mean
j
measurement results for each of test points, μSv·h
is the uncertainty of the calibration installation (from the calibration certificate), %.
CAL
The result of calibration is considered satisfactory if the basic relative measurement error does
not exceed corresponding limit stated in the section 1.2.3.
4.5.4 Determination of basic relative measurement error of AED of gamma radiation
Determination of the basic relative measurement error of AED shall be performed with one
value of AED equal to 90 μSv.
Perform calibration as follows:
1) turn the dosimeter on in the AED measurement mode and press the "START" button;
2) place the dosimeter on calibration installation with front panel towards the source and the
center of dosimeter's sensitive area located at the central axis of the gamma radiation beam at a
distance from the source corresponding to reference AEDR value 900 μSv·h
located 20 mm deep below the center of the circle at the dosimeter's front panel;
3) simultaneously start exposing the dosimeter to radiation and start the stopwatch;
4) stop exposure after t = 360 seconds and take readings in μSv from the LCD;
5) perform three measurements for this test point;
*
H
H
mean
j
1
1 .
j
*
H
ref
j
-1
;
FVKM.412113.026RE
9
-1
, the detector's center is
D in percents by the
i
2
*
ref
2
j
100
CAL
-1
, the detector's center is
-1
;
(4.1)
-1
;