AJAH.418266.007RE
3
This User Manual contains information on design, principle of operation, characteristics of the
product and instructions essential for correct and safe use of this product (intended use, maintenance,
servicing, storage and transportation), as well as information regarding the utilization of the product.
1 DESCRIPTION AND OPERATION OF THE PRODUCT
1.1 Product functionality
Detectors BDMN-200 AJAH.418266.007 (hereinafter detector) are intended for measurement
of the ambient equivalent dose rate of neutron radiation
10
*
(AEDR).
Detectors are used for monitoring of radiation environment at the industrial facilities: nuclear
plants, enterprises for radioactive waste conditioning and management and nearby areas, as a part of
systems, complexes and installations for radiation monitoring.
Detectors convert AEDR into electrical pulses with frequency proportional to the AEDR value.
The conversion function is determined as
10
H
М
K
10
H
N
*
*
,
(1.1)
where
N
– frequency of pulses, s
-1
;
K – sensitivity coefficient, Sv
h
-1
s;
M – “dead time”, s.
Registration of pulses and calculation of the pulse frequency to the AEDR units are performed
by the detector’s microcontroller. Data format of the AEDR value at the output of detectors is defined
by the DiBUS exchange protocol that provides possibility of data transfer to the external devices
intended for visualization, storage, and alarm signalling. Details on DiBUS protocol are presented at
www.doza.ru.
Detectors are manufactured in modifications that differ by data exchange interface:
BDMN-200DD AJAH.418266.007 - interface RS-422, BDMN -200PD AJAH.418266.007-01 -
interface RS-485.
1.2 Technical characteristics
1.2.1 Energy range of measured neutron radiation …….…..……….…..….. 0.025 to 10.0 MeV.
1.2.2 Measurement range of the AEDR of neutron radiation ………… 0.1 μSv·h
-1
to 0.1 Sv·h
-1
.
1.2.3 Limits of the permissible basic relative measurement error of AEDR of neutron
radiation ..…………….…………………………………………………………….………...…..
25 %.
1.2.4 Energy dependence for typical neutron spectra relative to the value obtained with neutron
spectrum of Pu-Be source ………….……………………………………………………………. ±40 %.
1.2.5 Detector’s warm-up time ….……………...….……………………... not more than 1 min.
1.2.6 Continuous operation without limitation of number of turning on/off ................ unlimited.
1.2.7 Instability during 24 hours of continuous operation relative to the mean value of readings
for this period ..……………………………………………………………...…… not more than ±10 %.
1.2.8 Power supply voltage (DC) .....…..……………..…………….….…..……….…
0
,
30
0
,
4
12
V.
Limits of complementary measurement error of AEDR of neutron radiation due to changes of
power supply voltage relative to the measurements at nominal voltage …………….…………… ±5 %.
1.2.9 Power consumption ………………..………..…………………….. not more than 2.0 VA.
1.2.10 Blocks provide generation of self-diagnostics codes and current measurement
information for the external information network based on interface:
-
RS-422 (DiBUS data exchange protocol) …………....….….….…….. for BDMN-200DD;
-
RS-485 (DiBUS data exchange protocol) …………....….…..….…….. for BDMN-200PD.