36
3) test intrinsic relative error in the reference points according to the Table 9.3
Table 9.3
Flux density at reference point,
оj
, min
-1
cm
-2
Measurements quantity, n
Statistical error, %, no
more than
10-30
5
5
400-600
5
5
4000-6000
5
5
40000-60000
5
5
200000-400000
5
5
4) do five measurements of alpha- radiation φ
ij
, as stated in item 2) in every reference point.
For every next measurement turn the reference source around the source geometric surface for 72
approximately (relative to the previous source position);
5) calculate average value
j
of
- radiation flux density for every reference point, using
Formula
5
1
5
1
i
ij
j
;
(9.17)
6) calculate intrinsic relative measurement error of flux density Q
j
, %, for every point, using
the Formula
oj
oj
j
j
Q
,
(9.18)
where
oj
– density of particle flux from active surface of the reference source as of the test
time, min
-1
см
-2
;
Verification results are considered positive if values of confidence limits of the intrinsic
relative measurement error of BDAB
- radiation flux density for all verifiable points, calculated
using the Formula (9.18), don’t exceed the limits of permissible intrinsic relative error
add
, calculated
using the Formula
)%
20
(
A
add
,
(9.19)
where А − coefficient equal to 10 min
-1
·cm
-2
;
φ – measured value of
- radiation flux.
9.8.3.9 Calculate intrinsic relative measurement error of β- radiation flux density for BDAB in
the following way:
1) connect BDAB to BDOI. Switch BDOI on and select β- radiation flux density
measurement mode;
2) close β- filter on the detection unit and place the detector very close to the reference source
90
Sr+
90
Y of the type 4SО, 5SO or 6SO, second category, so that the detector surface is parallel to the
source surface. At that the geometric center of the source surface must be perpendicular to the
geometrical center of the detector sensitive surface with
2 mm accuracy. Press OK button. When
statistical error value will be less than 5 %, press the STOP button;
3) open β- filter on the detection unit and install
-filter. Install detector in the same position
on the same reference source and press the START button. Read measured values of β- radiation flux
density
ij
when statistical error will be less than 5 %;
4) using the same source, do measurements according to items 2), 3) in the four mutually
perpendicular directions when the detector center moves by 15 mm relative to the source center;
5) do verification according to items 2) – 4) in reference points according to the Table 9.4
Содержание BDG1-PM1403
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