NUCLEONIX SYSTEMS GA720 User manual

I N S T R U C T I O N
M AN U AL
GAMMA AREA MONITOR
TYPE : GA720
NUCLEONIX SYSTEMS PRIVATE LIMITED
Plot No : 162 A & B, PHASE II, I.D.A.Cherlapally, Hyderabad - 500 051
Ph: 91-040-27263701/30918055, FAX : [phone], e-mail : [email protected]
File Name :GA720_Man
Date :02-04-2012

Contents
S.No. Description Page No.
Unpacking
CHAPTER I Introduction 01-01
CHAPTER II Front panel and Side panel controls / 02-02
indications / diagrams
CHAPTER III Specifications 03-03
CHAPTER IV Installation 04-04
CHAPTER V Operating Instructions 05-09
CHAPTER VI Side panel Connector Details 10-10
CHAPTER VI ICalibration 11-11
CHAPTER VIII Availing of maintenance / calibration services and
warranty clause 12-15
CHAPTER IX Block diagram & Description 16-17
CHAPTER X Factory acceptance Test /
QA Report / Calibration Data 18-24

UNPACKING
The Gamma Area Monitor Type: GA720 has been thoroughly tested and is dispatched in ready to operate condition.
However, on unpacking and prior to operation, it is advisable to check visually and make sure that there is no
visible damage caused in transit.
If any damage to the instrument is observed, do not switch ON the unit and report the matter immediately to:
Customer Support Division
Nucleonix Systems Private Limited
Plot No: 162 A& B, PHASE II,
I.D.A.Cherlapally,
Hyderabad - 500 051.
Ph : 91-040-27263701/30918055, FAX : [phone], e-mail : [email protected]
In all correspondence regarding the instrument, please mention the type, serial number of the unit, date of supply
etc., of the unit.

1
CHAPTER- I
INTRODUCTION
Gamma Area monitor (Micro) Type: GA 720, manufactured & supplied by NUCLEONIX SYSTEMS is designed
using state-of-art electronic devices (latest) including microcontroller with embedded code. Use of these devices
makes it compact & highly reliable. Powerful embedded code adds-up and enhances its performances and gives
extra advantage from the angle of fault diagnostics. This unit is primarily designed to indicate dose rates in the
range of (0-100mR/hr).
This unit will be useful for monitoring Gamma dose rate levels in working areas of Radio Isotope Laboratories,
Radiology departments, Medical & Industrial Radiological installations apart from its usefulness in Atomic Power
Stations and other active labs.
This unit goes into acquisition mode directly after power on after the initial introduction & self check. It indicates
dose rate digitally on 6x7 segment LED display as well a 16x2 LCD display. There are two visual annunicator lamp
windows GREEN & RED for NORMAL & ACTIVE conditions. The ACTIVE window flashes once the dose rate
alarm occurs and in normal condition the NORMAL lamp glows.
The user interface is through a front panel keypad comprising of EHT, PROG, INC, DEC, ACK & RESET keys.
PROG key shows up different menu options on successive operation. INC, DEC are used to scroll / select various
PROG options. ACK and RESET are used for acknowledging and resetting the unit during Active mode. The unit
has user selectable options like Alarm preset level, Baud rate (for serial communication), Reset mode (auto or
manual) and other system settings. Pressing EHT key displays the current EHT value in the detector probe.
For external detector arrangement the detector can be connected 10 meters away from the monitor through a
cable arrangement.
Some important features of this unit are :
qMicrocontroller based design has been employed
qDose rate range covered (0.1 - 100) mR/hr
qAuto ranging & auto TC selection in the range of 16 sec to 0.5 sec depending upon dose rate
qLarge size 6x7 segment LED indication for dose rate is provided
qDesigned using LND GM tube type 712
qLarge size WINDOWS for NORMAL & ACTIVE alarm condition
q16x2 LCD display dotmatrix display for visualization & settings of various options
VIEW OF GAMMA AREA MONITOR
TYPE : GA720

2
CHAPTER - II
FRONT PANEL & SIDE PANEL CONTROLS
2.1 FRONT PANEL CONTROLS
2.1.1. NORMAL & ACTIVE LAMPS
The NORMAL lamp (GREEN) glows during acquisition mode until the dose rate exceeds alarm preset
value. Once dose rate exceeds alarm preset value then the NORMAL lamp turns OFF and the ACTIVE
lamp (RED) blinks. Once the dose rate falls below the preset level, then (i) if Reset mode is AUTOthen
it comes back to normal mode. (ii) if RESET mode is manual, then it comes back to normal mode only
after RESET key is pressed.
2.1.2. DOSERATE (mR/hr) [6x7 segment display]
This gives the visual display of the current dose rate in acquisition mode. On pressing EHT key it displays
the current EHT value. It also displays fault conditions like EHT fail, Supply fail. It also displays the
overrange indication by blinking the maximum dose rate.
2.1.3. STATUS DISPLAY: [16x2 LCD dot-matrix display]
This is a 16 X 2 alpha numeric LCD dotmatrix and responds to all the commands from the keypad and
displays dose rate in acquisition mode with “A” blinking. It also displays the different parameters like
Preset alarm level, Reset mode, Audio status, Baud rate, Calibration adjustment, Audio frequency
adjustment.
2.2. SIDE PANEL CONTROLS
2.2.1. MAINS
This is a 3 pin MS connector for connecting the power cable.
2.2.2. ON
This is a toggle switch (inside the unit) which is used to power the unit. When the switch is put 'ON' the
mains AC power is available to the unit.
2.2.3. AUDIO ALARM
There is an audio alarm also which produces loud beeps alternately with the ACTIVE lamp. The audio
alarm can be turned off by pressing ACK key. It can be made OFF permanently through the AUDIO
ALARM - ON/OFF option in PROG menu.

3
CHAPTER - III
SPECIFICATIONS
Radiation detected :X – ray & Gamma Radiation
Range :0.1 mR/hr to 100 mR/hr
Detector :Halogen quenched GM tube LND712
Accuracy :+/-10% Full scale
Display :Auto – ranging direct reading, 6digit 7 segment LED display & 16x2 LCD display.
6x 7 segment display is interfaced using multiplexed display driver IC & used
for display of dose-rate information. 16x2 LCD for visualization of preset alarm
& other parameters.
Time Constant :Time constant varies continuously from 16 sec to 0.5 sec depending upon
countrate
Calibration Accuracy :+/-10% throughout the range
Calibration Stability :Better than +/-10% over a period of six months
Alarm range :0.1 mR/hr to 99.9 mR/hr
Alarm setting accuracy & stability
Better than +/-10% over a period of six months
Alarm System :a. Alarm indication is by flashing Red (LED) large area window display and
Loud audio alarm
b. Distinctive EHT / Detector failure alarm
c. The instrument has alarm acknowledgement and Reset switches on front
panel
d. Provision for remote alarm acknowledge and reset
e. Alarm annunciation scheme: as tabulated below
Condition Visual indication Audio
(Red LED)
Normal OFF OFF
Abnormal (Active) Flashing ON
On acknowledgement
after being abnormal Steady Red OFF
Reset after returning to Normal OFF OFF
Monitor Enclosure :Vapour-tight, rugged & elegant. The instrument can be offered with compliance
to required IP standards.
Mounting :Monitor is wall-mountable type.
Data Storage :Microcontroller has on-chip EEPROM to store the preset alarm levels and other
settings.
Self-Diagnostics :The monitor has built-in self-diagnostics. On being powered it performs tests to
check for the High voltage supply, Detector and pulse processing electronics .
Power :230 VAC +/-10%, 50 Hz, single-phase supply.
Environment :The instrument will be able to withstand temperature upto 60 deg C and relative
humidity upto 90% in radiation areas.
Front panel keypad :Keypad provided on Front Panel facilitates user to configure & program the Area
Monitor (deactivated by internal jumper selection).

4
CHAPTER - IV
INSTALLATION
This unit can be used as wall mounted unit or can be operated as a table top model. For wall mounting arrangement
the unit is provided with suitable clamps to be fixed on to wall and hooks have been provided on the unit for
hanging. The unit is provided with two handles for lifting and shifting purposes.
For installing the unit, Mains cord is to be fixed to the three pin circular connector on the unit side and the other
side through the three pin plug to 230V A.C. mains supply.
Now the unit can be switched ON for use. Alarms can be preset to the desired level.
The unit goes into dose rate acquisition mode on power on after performing hardware self check. The dose rate
in mR/hr is indicated both in the 6x7 segment display as well as in the 16x2 LCD display.

5
CHAPTER –V
OPERATING INSTRUCTIONS
5.1. INTRODUCTION: This chapter illustrates details on configuring and operating the instrument, for a
desired installation in a plant environment. Basically, operating instructions are illustrated with the
help of menu options / responses that appear on LCD / LED displays. Each of the menus facilitate
the user to choose function/ value to be set or entered as desired for its operation, at the installed
location.
An important note (to follow) for the user is
- key can be used to increase the value at the cursor position / toggle the option.
 - key can be used to shift the cursor position from right to left / toggle the option.
5.2 POWER ON CONDITION: When instrument is switched on, initially, the audio visual observations
noticed till the indications shown are stable is called power on condition.
When the power is switched on, the following audio visual indications are noticed. First, to start with,
one audio beep is heard. Followed by this the following visual indications will be lit. Red cluster LED
window will flash for a while and goes off. Followed by this, normal cluster LED window will be lit,
additionally other LED’s for” dose rate unit” indication will all glow for a while and default selected
unit LED will lit permanently. The status of LCD and large LED display with power on condition is
given in the following table.
When we switch ON the unit, the LCD display will show-up
LCD display
AREA GAMMA
MONITOR
for 1 sec
Then
NUCLEONIX
SYSTEMS
for another 1 sec
Followed by this, unit goes into acquisition mode and displays the following on
½ “ LED display
XXX.XX
And 16x2 LCD display
XXXX.XX mR/hr A
Character ‘A’ blinks indicating that dose rate acquisition is ON & mR/hr unit is default unit, stored.

6
5.3 ENTER PASSWORD
Now to program & configure the unit for desired functions or to change preset values, user has to
go through ‘PROG’ button / key. Different menus will appear as follows. On pressing ‘PROG’ key
first time unit will display menu as follows, prompting the user to enter factory set four digit
PASSWORD
ENTER ^
PASSWORD : XXXX
To enter the password use orkeys. If the password entered is correct then it will go to next
option of the menu as given below & facilitates the user to enter ‘ALARM SET POINT’.
5.4 ALARM SET POINT
GA720 will show the current default alarm set value of 5.00 mR/hr. If user wants he can change to
another value, by orkeys.
ALARM SET
POINT : XXX.XX
Once alarm set point is programmed, user can Press ‘PROG’ key once again to go to next option in
the menu i.e., given below.
5.5 RESET MODE
RESET AUTO/MANU
MODE
‘RESET’ option user can either set it as AUTO or MANU (manual). In manual reset, user has to
press the RESET button to bring back the unit into normal mode, once the dose rate falls below the
alarm set point. In auto mode, once the dose rate falls below the alarm set point, the unit
automatically returns to normal mode and the alarm condition is turned off. AUTO/MANU option can
be selected by orkeys. Default setting is = Manual
Once RESET MODE, option is selected user can now press ‘PROG’ button to go to next menu
option i.e ‘Audio Status’
5.6 AUDIO STATUS
There are FOUR options, for the user and any one of the options can be selected byor keys.
D = TONE / TONE 2 / TONE 1 /OFF
These four options include dual tone, Tone2, Tone1 & off mode. Once this option is selected then
press ‘PROG’ key to go to next menu option ‘BAUD RATE’. Default setting is = D TONE

7
5.7 IP ADDRESS
XXX.XXX.XXX.XXX
5.7 BAUD RATE
Baud rate is to be selected for data communication in a networked environment for RS485
communication. There are two options as indicated in LCD display.
BAUD RATE 9600/19200
One can select any of the two options for baud rate by using byorkeys. Having done that, user
can go to next option by pressing ‘PROG’ key. The next option that appears in LCD display is
hardware check. Default setting is = 9600
5.8 HARDWARE CHECK
Hardware check can be performed by orkeys.
HW. CHK
This checks LV supplies & EHT. If these are found to be alright, display prompts with an indication
as ‘OK’. Following this indication user can now go to the next option in menu by again pressing
‘PROG’ key. This prompts a menu as ‘calibration factor’.
5.9 CALIBRATION FACTOR
This is a feature provided in the design, to facilitate the user to set calibration factor such that
the calibration accuracy is within specified range. It may so happen that detector to detector
sensitivity may slightly vary & by setting this value suitably one can get desired calibration
accuracy. Range provided is 0.75 to 1.25 for calibration factor.
CALIB. XX.XX
FACTOR
By default it is set to 1.00 default. If user wants to go through calibration again, after changing the
calibration factor, he may do so. Having set this & upon pressing ‘PROG’ key, the next menu
option that appears is SET UNIT.
5.10 SET UNIT (setting of Engineering unit)
Here there are four options that appear in the LCD display as shown below
SET UNIT mR/hr / Sv/hr / cps / cpm
User can select any one of the four units as required by his plant / facility. However by default,
mR/hr unit is set at factory. Selection is byorkeys. The next menu option that will appear, on
selection of ‘PROG’ key after this above function set, is ‘DEVICE ADDRESS’.
Default setting is = mR/hr

8
5.11 DEVICE ADDRESS
This is a three character numerical value. This is RS485 address of the instrument limits 0 - 255
Default settings is = 000
DEVICE
ADDRESS XXX
User can select desired three digit address (ID) of the instrument. Use or keys to load this
value. Having completed this task press ‘PROG’ button for the next menu i.e., ‘AUTO ACK’
5.12 AUTO ACKNOWLEDGE
This is a selection option for alarm Ack
AUTO ACK ON/OFF
(5 min)
By orone can select or toggle this option. If it is selected as ON, after 5 minutes
automatically alarm is acknowledged & audio alarm goes ‘MUTE’. However visual alarm remains
active. Followed by this the next menu option is ‘MAX SCALE’ which is prompted on pressing
‘PROG’ button. Default setting is = OFF
5.13 MAX. SCALE
Depending on the unit chosen i.e., mR/hror µSv/hr or cps or cpm, the maximum permissible scales
are 100, 1000, 2000 and 50,000 respectively. User can choose anyvalue upto a maxof thisupper
limit & a value above the minimum value. Any value chosen out of these boundaries will be
ignored, (at the time of saving settings) and default values will be loaded . In the display, chosen
unit will appear & appropriate max value desired can be entered by the user. Similar is the case for
other units such as Sv/hr, cps or cpm. After selection of max. scale, user can now select ‘PROG’
button to go to next menu option, as follows. Default setting is = 100.00mR/hr
MAX mR/hr
(4-20mA) XXX.XX
5.14 MIN. SCALE
MIN mR/hr
(4-20mA) XXX.XX
Depending on the scale selected initially, appropriate unit (i.e typical mR/hr) appears in the display.
User cannot enter the min. scale value which is equal or above the max. scale value selected. Any
value not meeting boundary conditions will be ignored while saving the settings & default value will
be loaded. Similar if the engineering unit changed then the min. & max. scales are tabulated as
follows,

9
Engineering Unit Max. scale (4-20mA) Min. scale (4-20mA)
mR/hr 100.00 000.00
Sv/hr 1000.0 0000.0
CPS 2000 0000
CPM 50000 00000
Followed by this, on pressing ‘PRG’ button, the following menu appears ‘load default settings?
Note : Max. & Min. scales are primarily for current loop scaling, for control room operation. Also, in
the visual LED display also the same scales are set. Any value exceeding this max. scale will show
as over range, as per definition in the LED display However in the lower LCD display it continues to
show dose rate, as per actual value. Default setting is = 000.00mR/hr
5.15 LOAD DEFAULT SETTINGS
In case the user wants to retain default settings, he can skip all the previous menus & select this
menu & chose option by pressing orkey for default settings.
LOAD DEFAULT
SETTINGS?
Followed by this selection & upon pressing ‘PROG’ key one would see the menu as given below.
5.16 MODIFY PASSWORD
MODIFY
PASSWORD YES/NO
If user wants to change the pass word, he can do so by or key. Select no option to retain same
password. Having done that, finally we have completed all the ‘PROG’ button functions & are ready
to save settings. The next menu that appear as given below.
5.17 SAVE SETTINGS
SAVE ?
SETTINGS
Use or keys to save all the above settings. These are permanently stored in the EEPROM
and will be recalled at next powering on of the instrument. Having configured for required settings
unit is now ready for operation, once settings are saved unit automatically gets into operation mode
and starts acquiring dose rates and indicates in the display visually.

10
17 pin MS (panel mount connector)
A
B
C
E
F
G
H
D
J
K
L
M
CHAPTER - VI
SIDE PANEL CONNECTOR DETAILS
a. 3 pin MS Male connector (Mains)
Pin Number Signal
1Live
2Neutral
3Chasis/Earth/GND
b. 17 pin MS Male connector (EXT I/O)
Pin Number Signal
A,B,C,D,E,F No Connection
GCOM Changeover II
HN/C Changeover II
JN/O Changeover II
KCOM Changeover I
LN/O Changeover I
MN/C Changeover I
N,R,P No Connection
c. 6 pin MS connector Male connector (To Detector Probe)
Pin Number Signal
AGND
B+5V
CRS-485 (“A”) (For connecting to detector side
DRS-485 (“B”) RS485 Transceiver)
EFraction of HV
FNC
3 pin MS
(panel mount connector)
1
2
3
6 pin MS (panel mount connector)
A
E
D
C
B
F

11
CHAPTER - VII
CALIBRATION
Procedure for Calibration with Source
This unit namely Gamma Area Monitor Type GA 720 has been calibrated at Radiation Standard & Calibration Lab
of Nucleonix Systems (P) Ltd., using Gamma Survey Instruments Calibrator of AEA Technology, USA. It operates
in the range of Dose rate mode (0.1 mR/hr – 100mR/hr) for Gamma Radiation.
Calibration Procedure with Gamma Source (Cs – 137 – 136.742mCi)
The instrument is calibrated with gamma instrument calibrator of Nucleonix Associates. This comprises of a 164
mCi – 137 gamma source traceable to NIST.
The monitor is pre-loaded with a lookup table for computation of dose rate. To calibrate instrument with source,
expose the detector to below dose rates and record the observed dose rates. Detector axis is to be perpendicular
to source beam. Keep the source at marked up positions for various dose rate and observe the monitor reading.
Very Important Note : Please note that for a required dose-rate, always choose to keep detector probe at
maximum possible distance from source with minimum no. of lead block attenuators. This is to prevent scattering
effect due to attenuator blocks at close distance (<50 cm)
Now in case a reading exceeds the tolerance of +/- 10%, of expected dose rate then adjust calibration factor or
monitor such as to make entire readings fall within +/- 10% of expected dose rate.
When the manual is dispatched to the customer, calibration factor is to be mentioned below and also saved in the
instrument program.
Over Load Test Passsed
(a) 10 Times Highest Range Yes/No
(b) 50 Times Highest Range Yes/No
(c) 100 Times Highest Range Yes/No
Calibration Factor :__________________ Calibrated by :________________
Calibration Date :__________________ Instument S.No. :________________
Calibration Due :__________________
Tested By :Approved By :
Date :Date :
E
xpected
D oserate (mR/hr) Observed Doserate (mR/hr)
0.0 m R/hr
1.0 m R/hr
5
.0 mR/hr
10.0 m R/hr
2
0.0 m R/hr
50.0 m R/hr
10
0.0 mR/hr

12
CHAPTER - VIII
AVAILING OF MAINTENANCE/ CALIBRATION SERVICES AND
WARRANTY CLAUSE (with in India)
8.1 GENERAL
As per the warranty clause of the company, we provide one year warranty during which period we provide
free service at our works. Hence in case of any mal-function in our instruments, you are requested to send
the unit back to our works by RPP/COURIER/SPEED POST PARCEL/GATI/XPS/door delivery. We shall
arrange immediate rectification/replacement within two weeks from the date of receipt of the equipment at
our place. Please note that the equipment will be serviced at our works only.
The equipment is to be sent to:
The Servicing Department
NUCLEONIX SYSTEMS PRIVATE LIMITED
Plot No: 162 A& B, PHASE II, I.D.A. Cherlapally,
Hyderabad - 500 051Ph: 040-27263701/329145448/32918055
E-mail: [email protected] www.nucleonix.com
For all the Radiation monitoring equipment, detectors built-in or external probes will not have one-year
warranty, but only inspection warranty at the time of supply is provided. Since detectors will / may have
fragile glass construction, we do not provide warranty. In case of failure of these components, Nucleonix will
supply detector replacement at cost-cost price.
Note: In respect of all types of portable radiation monitors, it may be necessary to checkup and recalibrate
the equipment once a year at our works.
8.2 EQUIPMENT REPAIRS / SERVICING POLICY (WITH IN INDIA)
(a) During Warrantee
The following procedure is to be followed by the customers with in India for availing services/ repairing
facility during warrantee period.
●Equipments are to be sent to our works for availing free repair services during warrantee, after the
customer receives approval from the customer support division, by sending an e-mail.
●For all equipments, costing less than 6.0 lakhs one year warrantee & free service is offered, when the
equipments are sent to our works only. For larger systems such as installed systems, networked
systems, specialized systems, costing more than 6.0 lakhs during one year warrantee, free service
is offered at site. Field service Engineer will be deputed subject to warrantee terms & conditions.
●This does not include personal computer related problems, for which local computer service provider
of the PC vendor is to be contacted. Also for software related problems online support will be provided.
Software support doesn't include cleaning of virus problems etc.
●When the equipments are sent to our works for warrantee services, they are to be properly packed
with adequate cushion to prevent any transportation damages. Nucleonix Systems is not responsible
for damages or loss during transportation.
●Packing / Freight charge is to be borne by customer when he sends the equipment to our works.
However when we return after servicing packing will be Nucleonix responsibility & Freight charges
will be to your account. Only services are free.
●Please indicate in your correspondence equipment model & serial number.
●All the equipments are to be sent to our works only on door delivery basis.
●For Door Delivery Transportation contact XPS/GATI cargo in your city / town or a reliable courier
service to pick the consignment from your place. For their nearest local address & phone no's look
into their websites. Transit insurance if the customer feels is necessary it is to be covered.
●Nucleonix Systems will not receive the equipments sent by other modes of transportation, such as
Rail/Road.
●After servicing, equipments will be sent back by same mode of transport such as XPS/GATI/COURIER/
RPP.

13
●All types of Radiation detectors, glass ware, PMTs etc which are fragile are not covered in warrantee,
if the failure is due to physical damage, external or internal due to shock, dropping, miss-handling
etc. If the failure is due to a natural fault then only it is covered under warrantee for a limited period of
three months. However complete electronics is covered for 1 year warrantee.
●You can also send the equipment personally to our works for repairs either during or after warrantee,
after fixing up with our service dept (Customer Support Division). If possible we may repair on same
day or your person can stay for a day or two & get it repaired & or calibrated.
(b) After warrantee Services
●On expiry of 1yr warrantee if you like to send the equipment (low cost less than 6.0 lakhs) for repairs
to our works, you may please observe the following procedure.
●Send an e-mail with details mentioning that you agree to pay service charges which includes: Basic
service charges per unit / module in the range of Rs: 2500 to Rs : 10,000 depending on the sophistication
of the unit calibration charges ( if applicable for your equipment) + cost of components + packing
charges + Return Freight charges @ actual.
●Once our customer support department responds & requests you to despatch the equipment to our
works for repairs, you may do so by following the steps given below.
●Followed by this you can send the equipment straight away if it is within 5 yrs old. If the equipment
is beyond 5 yrs old, then also you can send it for repairs, however only after you receive confirmation
from Customer Support Division, that it is repairable & is not an obsolete model. If the design is
obsolete then customer support division (CSD) may give you 'buy back' offer to replace with new
model or upgrade it with electronic circuit boards & enclosure.
●For all installed equipments costing above Rs: 6.0 lakhs which are larger in size & for which field
servicing only is recommended, you can obtain a quotation with relevant details by sending an e-mail
& avail the services accordingly.
●For all field servicing jobs, since we need to depute engineers, it is likely, to take time & also it will
cost more which includes Engineer's TA & DA etc., apart from basic service charges + cost of spares
etc. Please note that basic service charges will be different for different products depending upon
sophistication.
●Also in some cases it may not be possible to fix-up the problems in the field itself, in such cases we
may advise you to send them to our works.
●For all jobs to be serviced in the field, customer is requested to provide adequate details on the
nature of problems, to enable our engineer to come prepared with adequate spares.
●For any additional information send an e-mail to [email protected], Atten: Customer support division.
8.3 EQUIPMENT REPAIRS / SERVICING POLICY (FOR EXPORTS)
Equipments, manufactured & exported are subjected to a well defined quality assurance (QA) plan &
Factory acceptance tests (FAT). Nucleonix systems has the following policy to provide maintenance support
to overseas customers either directly or through international dealers / distributors.
(a) During & after warranty:
●For minor problems, which can be handled by customers, servicing tips have been provided in the
user manual / servicing manual.
●Also most of the equipments have built-in fault diagnostic features which will indicate to the user
nature of problem in the equipment. Based on the visual indication in the instrument Display, user
can take corrective action or contact Nucleonix systems by email for help.
●Nucleonix systems will guide in localizing the defective part / module or sub-system by interacting
with the customer if required. Skype will be used for communication.
●During warranty free replacement of sub-system or board (PCB) will be done. However customer has
to send defective sub-system back to Nucleonix system with-in 15 days on arranging replacement.
●During & after warranty, any Freight charges & customs clearance charges are to be borne by
customers, both ways.
●If it is a manufacturing defect, then Nucleonix system will bear the replacement cost of sub-system
/ unit. However any Freight charges & customs clearance charges in their country are to be borne by
customer.
●After warranty, services will be similar to that of services during warranty. However, customer will
have to pay for cost of parts replaced, freight charges both ways & customs clearance charges in
both the countries. Nucleonix systems plans to introduce audio visuals on web or on CDs to facilitate
product demonstration, installation & minor maintenance very soon.

14
8.4 HOW TO AVAIL CALIBRATION SERVICES (FOR INDIAN CUSTOMERS)
Nucleonix Systems offers radiation calibration services to its customers. Calibration services are provided
for Nucleonix Systems manufactured products only, in general, as a company policy.
How to avail calibration services:
It is best advised that each of the Radiation monitors including Area monitors are calibrated once in a year.
When you want to send your Radiation monitor / Area monitor / Contamination monitor for calibration to our
works. You may send the equipment for calibration, by following the steps given below:
1. Our standard calibration charges per equipment (All types of Radiation monitors including portable
survey meters, contamination monitors & Area Gamma Monitors) are Rs: 2500 + Packing + Freight
charges. You can email a 'work order' accepting these charges.
2. Email your work order and despatch / send the equipment to our works if it is 5 years old or less
including details of mode of transport sent with docket particulars.
3. Also mention in your work order & clearly indicate that you will agree to pay calibration charges &
also equipment repair charges additionally if the unit is faulty & requires repairs before one can take
it up for calibration.
4. You are requested to ensure good packing to avoid any transportation damages. Especially if there
are external detector probes, they are to be packed with sufficient soft foam to ensure no damage in
transportation.
5. Use only the specified following mode of transportation system for dispatching on door delivery
basis. XPS/GATI cargo / Courier/RPP/Speed Post parcel etc. Send the equipment on freight paid
basis. (Equipments sent by other methods such as Rail/Road etc will not be collected). Also you
can cover for transit insurance both ways if you wish. Nucleonix system is not responsible for any
transportation damages or loss during transportation both ways.
6. Immediately on receipt of the equipment, we will send an acknowledgement & also a proforma bill by
email/ post.
7. Based on the proforma bill, once we receive the payment, equipment will be dispatched back by
similar mode of transportation as mentioned above.
8.5 HOW TO AVAIL CALIBRATION SERVICES (FOR FOREIGN CUSTOMERS)
Foreign customers can calibrate Nucleonix make Radiation monitors/equipments in their country at any of
their accredited Radiation calibration labs. Nucleonix systems will be happy to provide any help and guidance
if needed, for calibration. Alternatively if you send the equipment here to India we can also provide calibration
services.
Calibration Standards Lab & Facility:
We have two calibration labs.
i. Low Level Calibration Lab.
ii. High Dose Rate Calibration lab.
Low Level Calibration Lab: This has a Cs-137, 165 mci standard. "Gamma Survey Instruments Calibrator"
from Amersham.
This calibration service has NIST Traceability standard. Calibration of all portable radiation monitors, survey
meters, contamination monitors, Area monitors etc., is carried out in this lab upto 1 R/hr max dose rates.
Gamma Survey instruments calibrator has Cs-137 source 161.5 mCi as on 05 Aug 2002. It is basically a
gamma survey instruments calibrator procured from AEA Technologies UK/USA. Has NIST traceability
accuracy within +/- 7%

15
Gamma Survey instruments calibrator has Cs-137 source 161.5 mCi as on 05 Aug 2002. It is basically a
gamma survey instruments calibrator procured from AEA Technologies UK/USA. Has NIST traceability
accuracy within +/- 7%
CRC-2 camera has Co-60 standard obtained from Bhabha Atomic Research Centre, Mumbai. It is a certified
source.
8.5 ANNUAL MAINTENANCE CONTRACT (AMC)
Annual maintenance contract (AMC) services:
For all sophisticated instruments & systems and also for installed monitors & networked systems in a
nuclear facility or a Radiological lab or in a Medical cyclotron facility where no. of instruments are networked,
it is advised that customer enters into an economical Annual maintenance contract with Nucleonix system.
Detailed AMC proposal can be obtained from our customer support division (CSD), by giving required
inputs.
Inputs required by our CSD to send you AMC proposal:
●Name, year & data of purchase, Sl. Nos. of equipments, Model No's, No. of equipments for which
AMC is required. Additionally no. of calls per annum required for preventive & breakdown maintenance
may also be indicated.
Advantage of entering into AMC:
●Equipment services offered will be prompt & timely
●Nucleonix systems maintain required spares, spare tested PCBs, detectors & other critical
components which may become obsolete.
●Obsolescence in electrons is quite rapid. If you enter into AMC guaranteed service for the period of
AMC will be the responsibility of Nucleonix Systems.
●Nucleonix Systems will maintain Engineers at your disposal to attend to AMC calls on time
●Without AMC prompt service calls are not guaranteed.
●If some critical components become obsolete, then Nucleonix systems may request you to upgrade
the product with new model or new electronics which may be expensive if you are not under AMC.
Training on maintenance / servicing:
●To a limited extent, we offer training on maintenance / repairs at our works to customers on chargeable
basis. Details can be obtained from our customer support division, by customers who may require
such services.

16
CHAPTER - IX
BLOCK DIAGRAM DESCRIPTION
Area gamma monitor GA720 is shown in block diagram on the next page. It mainly consists of two parts.
(a) Detector probe with associated electronics &
(b) Main measuring unit with majority of µC based functional electronics & embedded code.
9.1 DETECTOR PROBE ELECTRONICS
This consists of energy compensated detector 71210 or its equivalent, with pulse processing electronics,
TTL to RS485 converter and +500V, HV module for detector biasing. Detector output signals generated from
RS485 transmitter chip are fed to main PCB through 5 pin I/O cable, connected to the Electronic unit.
These signals are received by RS485 receiver chip & counted by a 6 digit BCD counter in the main PCB.
The output of this counter is read by micro-controller continuously. The +5V power supply, required for HV
module and pulse processing SIL chip, generated on main board, is taken through a 5 pin I/O cable, to this
detector probe unit.
9.2 MAIN PCB CIRCUITS
Low voltage supplies +5V, +18V, & +5V ISO are generated through mains transformer, secondary & three
terminal regulator chips. All these supplies are used internally to power-up various circuits, for their functionality.
Afour channel ADC reads fraction of HV & LVs & reports to micro-controller under program control to
indicate HV & LV failures if any to the user.
User interface to GA720 is through keypad command buttons EHT, PROG, INC, DEC, ACK & RESET.
These keys enable the user to configure & select various programmable options such as alarm set point,
unit of measurement, baud rate for communication, calibration factor & many more such functions etc.,
EEPROM serves as a memory device to store all the configured parameters including instrument ID etc.,
There are two visual displays provided (a) 16x2 LCD display & (b) 6 digit 7 segment LED display, driven by
multiplexed display driver. LCD display indicates all programmable functions & their values while programming
& it also indicates, dose rate, in acquisition mode (normal situation). ½ “ LED display indicates dose rate
in the selected unit (such as mR/hr or µSv/hr or cps or cpm)
The other interfaces to micro-controller include;
•Visual alarms (ACTIVE & NORMAL) cluster LED array GREEN & RED with their driver circuit to indicate
alarm & normal condition.
•A relay driver with relay PCB provides two sets of change over contacts for external use. This relay is in
energized condition in NORMAL condition of area gamma monitor & in de-energized state in ACTIVE
condition.
•For data transmission from area gamma monitor to SCADA, an RS485 interface has been built using TXD
& RXD pins of micro-controller. This facilitates area gamma monitors RS485 networking for data
communication. These RS485 signals have been brought out on a pair of 9 pin D-connectors (male / female)
for RS485 daisy chain connection of devices. Additionally these signals are made available on 17 pin also.
Most of the interfacing devices or circuits or peripheral chips are connected to micro-controller through I2C
bus, or ports or I/O expanders etc., for interfacing.

17
MCU
P89V51
RD2
Buffer 16x2 LCD
Display
Multiplexed
Display
Driver
4 digit 7
segment
display
Buzzer
(Audio Alarms)
Visual Alarms
(Active/Normal)
LEDs
Relay Driver
Relay Board
(2 c/o contacts)
17 pin MS
Keypad
EEROM
RS485 to
TTL
6 digit
counter
4 ch
ADC
+18V fract
+5V fract
Power Supply
+5V +18V
Transformer
9V rms 20V rms 9V rms
~
Main Board
-ve tail to TTL
convertor
TTL to
RS485
HV
(500V @ 50
mA)
HV fract
+5V
+500V
Detector Probe
GM Detector
LND 71210
+500V
230V AC
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