Beta-Gamma Hand, Foot & Clothing Monitor BM731 manufactured by NUCLEONIX SYSTEMS primarily serve as a personnel monitoring system for checking the contamination of hands, foot & clothing of radiation worker / technicians working in Nuclear Power Plants, reactors, Radiochemical plants and other similar installations.
This instrument uses state-of-art electronic devices including controllers with embedded code to perform powerful monitoring and fault diagnostic operations while monitoring.
Modular construction of hand/foot assemblies, PCBs & excellent engineering facilitate easy maintenance. Visual symbolic LED window displays for Left/Right Hand & Foot annunciation indication in the event contamination of that particular limb is a unique feature for NUCLEONIX make system.
Each Hand & Foot detector assembly shown in figure is modular in construction with two detectors plugged onto a single pre-amp box, facilitating easy maintenance incase of problems.
Features
State of art electronics design, using controllers with embedded code, serial bus based devices makes the equipment compact and highly reliable.
Uses GM133 for Hand/Foot channel detectors and GM137/GM133 for clothing probe.
User I/O interface is through a detachable keypad & large LCD dotmatrix display.
Centronics port for printing of settings and alarm information on printer.
Built-in serial port (RS485) provided facilitates networking for centralized monitoring and fault diagnostics purposes.
Monitor design ensures continuous maintenance free operation for a long time
Monitor is designed to withstand the harsh atmospheric conditions in Radiochemical plants.
Major controls, including keypad that can be detached are, inside the unit (behind lockable hinged doors) prevent unauthorized tampering.
Plug-in type PCB design with EURO connectors, facilitate easy replacements incase of failures.
Specifications
Hand Detector Assembly
Foot Detector Assembly
(a) Detector Assemblies:
The detector assemblies will be manufactured and tested as per IEC61098. 1) Hand Detector Assembly:
a. Number of monitoring Channels : FOUR (Left Hand Upper & Lower& Right Hand Upper & Lower)
b. Detector Type: Thin walled G. M. Detectors (GM 133)
c. Detector Wall Material: 446SS of area density 40–60 mg/cm2
d. Probe construction: Each channel has TWO G.M. detectors. The detectors are provided with necessary Lead shielding of 12/25mm thickness to keep the background counts low. The detector assembly with pre-amplifier are easily detachable for any maintenance.
e. Protection Grill: The whole detector assembly is given adequate protection against contaminated hand touching the detector body with a thin metallic SS grill. This design permits maximum viewing area.
(2) Foot Detector Assembly:
a. Number of monitoring Channels: TWO (Right foot & Left foot)
b. Detector Type: Thin walled G. M. Detectors (GM 133)
c. Detector Wall Material: 446SS of area density 40–60 mg/cm2
d. Probe construction: Each foot channel has TWO G.M. detectors. The detectors are provided with necessary Lead shielding of 12/25mm thickness to keep the background low. The detector assembly with pre-amplifier are easily detachable for any maintenance.
e. Protection Grill : The whole detector assembly is given adequate protection with a thin metallic SS grill, this design permits maximum viewing area.
f. Foot Assembly dust tray : An SS tray provided just below the foot detectors facilitate, periodical cleaning of foot dust that may fall into it, including any brushedout dust from the surfaces of GM tubes.
(3) Pre-Amplifiers : Each pair of detectors of Hand or Foot are plugged into a pre-amp box which has necessary electronics to convert detector tail pulses to TTL signal for counting.
Foot Assembly Dust Tray
Pancake Detector Probe
(4) Clothing Probe :
a. Number of monitoring Channels: ONE
b. Detector Type: Thin walled G. M. Detectors (GM 133 / GM137)
c. Detector Wall Material: 446SS of area density 40–60 mg/cm2
d. Probe construction: Hand-Held type. Side window probe in a protective housing with a rotatable shutter for cutting off Beta particles. It is placed in a holder with micro-switch assembly on the side of the monitor. On removing the detector from the holder the monitoring will be initiated.
e. Pre-amp & HV, for this are built-into a small box, housed inside the Hand monitor assembly.
(b) Electronic Unit :
The Electronic Unit consisting of chassis fitted with pluggable PCBs with EURO connectors are housed in vertical column of the unit & is covered by a hinged lockable door. Hand detector assembly is mounted on this vertical column. Foot detector assembly with its rectangular base is provided with lockable castor wheels at the bottom for ease of movement during installation. Onto the rear end of this foot assembly, vertical column is hinged. All the interconnecting cables between various detector assemblies to electronic unit are routed neatly, through the vertical column.
Electronic Unit essentially has the following PCB modules
• Low Voltage PCB – ONE
• High Voltage PCB – TWO
• Slave Controller with counters –ONE to carry out the following functions.
• Provides required low voltage to all circuits.
• Provides HV biasing to all twelve GM 133 detectors.
• Counting of the detector pulses, computing / control logic, storing the counts and transferring them to Master Display controller etc.
Additionally there is a Display Module fixed on the top of Hand Monitor assembly :
This unit has Master controller with all visual display windows, status LEDs and 20x4 LCD charactor display / 7.5” colour LCD display, serial port and centronics printer port etc. It reads all data from slave controller / counters PCB and presents visual indication (status on Hand/Foot & Clothing contamination) to the user.
• Counters : 13 individual counter ICs are used for counting pulses coming from each of the detector channels
• EEPROM : EEPROM is provided for storage of programmable parameters, default settings & alarm data.
• Counting Start and Stop Commands : Start and Stop signals for counting from the Detector channels are generated by the optical sensors
• Hardware Test Diagnostics: Hardware test diagnostics for checking complete hardware are performed by the Control Unit. The various checks performed are EHT check, Power supplies check, Detector Failure Check, High Background Check, Counter Electronics Check, etc. Complete diagnostics are performed at power-up. or on user prompt.
• Audio & Visual Alarms : Clear or active indications will be generated if the net counts or count rate exceeds for any one channel. Counting will run for preset time. Incomplete operation & high background will generate alarms immediately.
• Alarm Indications :
a. CLEAR : GREEN LED WINDOW for counts less than set limit – Short Audio Sound
b. ACTIVE : RED LED WINDOW for each channel – COUNTS greater than set limit – Long audio tone
c. INCOMPLETE : AMBER LED WINDOW – counting interrupted operation – Short Audio Sound
• Ranges : Hand Channels 0-9999 countsDPM/Bq, Foot Channels 0-9999 counts/DPM/Bq, Clothing channel 0-9999 CPM/CPS/Bq and Counting time 0-99sec
• Background Subtraction : Automatic background calculation & subtraction is done periodically. Audio-visual alarms are generated if background exceeds preset level.
• Detector Isolation: Incase of any of detectors becoming faulty , the corresponding detectors can be manually disabled. Once disabled the data from that detector is not counted for BG & counting mode.
• Relay Contacts : One potential free contact for each of the following conditions (Optional)
a. Alarm Condition
b. EHT Failure
c. Background High
• Human Machine Interface: Human Machine Interface is provided through a detachable hand-held keypad.
• Indications and Sensors:
Optical Sensors: The monitor is provided with optical sensors inside the detector cavities for initializing the counting.
• 20x4 LCD charactor display / 7.5” colour LCD display, for visual indication of all parameters.
• Multi-lingual message support for 7.5” colour LCD display during monitoring (Hindi/English/Tamil)
• Computer Interface : (Optional)
The monitor has got an RS-485 port for communication with Remote PC terminal through RS485 port.
(c) RS-485 Interface:
The monitor is provided with RS485 port below specifications to facilitate remote monitoring and diagnostics
RS-485 Specification :
Type : Multi-drop serial communication port, half duplex bi-directional communication
Address : User configurable from 0 to 255
Protocol : MODBUS RTU
Bit Rate : user 19200
Connector : 9 Pin D – Type Connector
(d) Input Power :
230 VAC +/- 10%, 50 Hz, single phase supply, power ON/ OFF switch control & indication are provided in the vertical column enclosure of the monitor.
(e) Environment :
The instrument is designed to with stand temperature up to 55°C and relative humidity up to 90%.
(f) Housing :
The housing is made of MS and all the major electronic assemblies are contained in the vertical coloumn. Hand assembly is assembled on the vertical coloumn. The foot probe is attached to this vertical coloumn at the foot level.
(g) Compliance : Instrument will meet all requirements applicable
(a) ANSI N 42.17
(b) IS -9000 part III & V
(c) Interference test as per IEC61000 or equ.
(h) Hand held Configurator (Optional)
• It facilitates reading monitor ID, fault Diagnostics, current count rate, preset alarm levels, current alarm status, baud rate etc.
• It uses 20x4 LCD character display.
• 2x3 tactile keypad for data counting / setting & parameters viewing.
• Uses dry cells 1.5V x 4.
Beta - Gamma Clothing Probe
Display Module
Clothing Probe with GM133 (LND 719
Pancake Detector Probe
Plot No.162 A & B, Phase-II, IDA, Cherlapally, Hyderabad-500051 India Phone:+91-40-27263701, 32918055, 32914548 Fax : 040 - 27262146
Copyrights (c) 2008, Nucleonix Systems, All rights reserved.
