AJAH.418266.007RE
10
4.3 Safety precautions
It is necessary to follow safety requirements described in section 3.2 and in documentation
accompanying calibration tools and equipment.
4.4 Conditions
4.4.1 The following normal operating conditions shall be met during calibration:
-
air temperature ……………………………………….…….…………………. +(20 ±5) °C;
-
relative air humidity ……….……………………….….....……..……...… from 30 to 80 %;
-
atmospheric pressure ………………………………………………….… 86.0 to 106.7 kPa.
4.4.2 The detector before calibration should be placed in conditions as per section 4.4.1 and
kept under these conditions for 4 hours.
4.5 Procedure
4.5.1 External examination
The items to be checked during external examination:
-
proper completeness;
-
absence of defects which could affect the detectors operation;
-
availability of operational documentation.
4.5.2 Testing
Perform the following operations to test the detector:
-
connect detector to PC consulting with fig. 2.1;
-
apply power supply voltage;
-
Start the “TETRA_Checker” software on the PC and make sure that detector parameters
have being correctly read;
-
click on the program’s panel on the “PARAMETERS” button and select request via
broadcast address.
The detector operability can be checked by presence of indication of a measurement result in
corresponding window of the “TETRA_Checker” software.
4.5.3 Determination of basic relative measurement error of AEDR of neutron radiation
4.5.3.1 Determine the basic relative measurement error by means of successive exposure of the
detector to a set of AEDR of neutron
radiation
in the ranges: the first value is selected within the range
10 to 100
Sv·h
-1
; the second - 300 to 700
Sv·h
-1
.
4.5.3.2 For taking measurements detector should be placed in the radiation field of the
calibration installation so that the axis of the collimated beam be perpendicular to the longitudinal axis
of detector and pass through the center of the neutron moderator.
4.5.3.3 Determine measurement results at the first and the second AEDR points as the average
of five readings taken with interval of 100 seconds for each point.
4.5.3.4 Calculate the relative error
of AEDR of neutron radiation in per cent using the
following formula
100
H
H
H
*
0
*
0
*
(4.1)
where
*
0
Н
- is the AEDR value reproduced by the calibration installation,
Sv·h
-1
;
*
Н
- AEDR value as measured by the detector,
Sv·h
-1
;
The detector is considered valid if the main relative error of measurement at both points does
not exceed the value stated in the 1.2.3.
