NUCLEONIX SYSTEMS PRIVATE LIMITED GR612 User manual

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NUCLEONIX SYSTEMS PVT LTD
I N S T R U C T I O N
M A N U A L
GAMMA RAY SPECTROMETER
TYPE : GR612
NUCLEONIX SYSTEMS PRIVATE LIMITED
Plot No : 162 A & B, PHASE II, I.D.A.Cherlapally, Hyderabad - 500 051
Phone: [phone],
FAX : [phone],E-mail : [email protected]

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EIX SE
CONTENTS
S.No. Description Page No.
Unpacking
CHAPTER I Introduction
CHAPTER II Specifications
CHAPTER III Front Panel & Rear Panel Controls
CHAPTER IV Operating Instructions
CHAPTER V PC Communication (optional)
CHAPTER VI Block Diagram & Description
CHAPTER VII System Interconnections
CHAPTER VIII Maintenance
CHAPTER IX Contact Us for Availing Services 21-24
19-20
18-18
16-17
15-15
10-14
04-04
04-07
08-09

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S V
UNPACKING
Gamma Ray Spectrometer Type :GR 612 has been thoroughly tested and is despatched 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, 32918055, 32914548FAX : [phone],
e-mail : [e-mail] (or) [e-mail]
In all correspondance regarding the instrument, please mention the type, serial number of the unit.
Also if you find any short supply and missing items, not tallying with the packing slip, the same is to be reported
immediately by e-mail/FAX and all the original packing is to be preserved intact till the matter is settled.

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NUCLEONIX SYSTEMS PVT LTD
CHAPTER - I
INTRODUCTION
GAMMA RAY SPECTROMETER TYPE : GR 612 manufactured by Nucleonix Systems is a state-of-art
microcontroller based modular unit consisting of LV Power supply card, High Voltage Card, Linear Amplifier card,
Single Channel Analyser and Controller based Timer/Counter Cards housed into a single enclosere.
The Gamma Ray Spectrometer GR 612 essentially accepts the input pulses from a Scintillation Detector which
givesout electrical pulses proportional in amplitude to the incident Gamma energy. Low Voltage unit provides the
necessary LV supplies to powerup the circuits for their functionally. The High Voltages card provides the necessary
bias for scintillation detector. The detector output amplified by Linear Amplifier is fed to the Single Channel Analyser
for pulse height analysis. The output events from SCA are counted for a preset time in Controller card. SCA is an
important unit in GRS which scans the entire Gamma Spectrum. Controller card has built-in Six digit serial
counter & under programme control it can store the data in CPS, CPM & counts for preset time mode. It has three
modes of data. Readings upto 1000 readings can be stored and recalled on to the LCD dotmatrix display. Also
data counts can be printed directly onto a printer through printer port or downloaded into a PC through serial port
under software control.
Gamma Ray Spectrometer GR 612 manufactured by NUCLEONIX is widely useful for teaching & research labs in
Universities & R&D labs in the field of Nuclear & Radiation physics experiments and this system also can be used
for Radiochemistry work & also in Nuclear power plants for Gamma sample counting.

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NUCLEONIX SYSTEMS PVT LTD
CHAPTER - II
SPECIFICATIONS
1. HIGH VOLTAGE PCB
a. Output voltage variable continuosly from 0 to 1500 volts.
b. Output current (maximum) 1mA.
c. Load and Line Regulations : better than 0.05% of full scale
d. Indefinite overload and short circuit protections and self recovery.
e. Output ripple less than 25 mV.
f. Dimensions : Two bit Module.
g. HV is adjustable by ten turn helipot with knob.
h. HV indication is provided on a 20x2 LCD DOT MATRIX DISPLAY
2. LINEAR AMPLIFIER PCB
a. Input Polarity : Positive or Negative
b. Total Gain ( Typical) : 500 ( approx)
c. Output (Unipolar) : 0V to 8V (usable recommended Linear range)
d. Max. Output (Unipolar) : 12V (Saturation Level)
3. SINGLE CHANNEL ANALYSER PCB
a. Input : Unipolar or Bipolar with a +ve leading edge 0 to 10V
b. Output Pulse Polarity : Positive
Pulse Amplitude : +5V
Pulse Width : 0.5 micro sec
c. LLD output pulse amplitude : +5V
Output pulse width : 0.5 micro sec
Base line variable by : 10 turn helipot / Dial
Base line variation : 0 to 10 V by helical potentiometer
d. Window width continuosly : Variable by helical potentiometer / Dial
Window : 0-1V in WINDOW mode
ULD range : 0-10V in NORMAL mode
e. LLD, ULD & MODE switch, controls have been provided on front panel
4. COUNTER TIMER PCB
: 20x2 LCD dotmatrix display has been provided to indicate data counts
& Elapsed time
: 0-9999 seconds
: START, STOP, PROG, STORE, INC & DEC command buttons have
been provided on the front panel key board
: a. Counts for a preset time b. CPS c. CPM
: Programmable through switch control buttons
: Upto 1000 readings
: includes selection of preset time storing / recalling of data, starting
and stoping of acquistion, lable assignment for data counts such as
BG (back ground), ST (standard) and SM (samle).
:
a. Display
b. Preset time
c. Command Buttons
d. Modes of Data
Acquistion
e. Preset Time Selection
f. Data storage
g. Programmability
h. Serial port
: This module additionally has built-in RS232C serial port for down
loading the data into PC.

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NULEO SSTEM PVTTD
5. EXPERIMENTS :
a Study of energy resolution characteristics of a scintillation spectrometer as a function of applied high voltage
and to determine the best operating voltage.
b Study of Cs-137 spectrum and calculation of FWHM & resolution for a given scintillation detector.
c Study of Co-60 spectrum and calculation of resolution of detector in terms of energy.
d Energy calibration of Gamma Ray Spectrometer (Study of linearity).
e Spectrum analysis of Cs-137 & Co-60 and to explain some of the features of Compton edge and backscatter
peak.
f Unknown energy of a radioactive isotope.
g Variation of energy resolution with gamma energy.
h Variation of gamma intensity as a function of distance (Verification of inverse square law).
i Activity of a Gamma Source (Relative Method).
j Activity of a Gamma Source (Absolute Method).
k Mass Absorption Coefficient.
6. APPLICATIONS :
Y
X
NI
The system finds wide range of applications in nuclear research and academic fields which include analysis
of Gamma Radiation, Identification of unknown isotopes and their relative adundance.
Measures the strength of Radioactivity of sample.
Useful in radiotracer techniques.
Can be used for protein bound iodine studies in medicine using well type scintillation detector etc.
Swipe sample counting in Health Physics Labs.
SCINTILLATION DETECTOR :
Scintillation detector with flat type NaI crystal of 1"X1" or 1 1/2" X 1 1/2" or 2" X 2" or 3"X3" flat or well type
detector of 1 1/2" X 1 1/2" or 2" X 2" of NUCLEONIX make or its equivalent is compatible to GR612. The
output of these units (taken from preamplifier) is POSITIVE for all Nucleonix make Scintillation detectors.
Hence the input polarity of the amplifier in GR612 is to be selected for POSITIVE. Scintillation detector
preamplifier required LV supply of 12V is drawn from the GRS rear panel. So, also the HV bias supply for the
PMT of the detector assembly is also drawn from GRS rear panel. Preamplifier of the scintillation detector is a
charge integrating type of preamplifier which gives out positive output. This output from scintillation detector is
fed to input (BNC) of the amplifier part of the Integral GRS(I).
SERIAL PORT (RS232C) (OPTIONAL) :
Built-in serial port facilitates stored data transfer under PC programme control. This transferred data can be
further processed if required by the user in PC.

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NUCLEONIX SYSTEMS PVT LTD
(D) ACCESSORIES
SCINTILLATION DETECTOR (S) :
ScintillationdetectorwithflattypeNaIcrystalof1"X1"or2"X/2"or3"X3"welltypedetectorof2"X2"or3"X3"of
NUCLEONIXmakeoritsequivalentiscompatibletoGR611(I).Theoutputoftheseunits(takenfrompreamplifier)is
POSITIVEforallNucleonixmakeScintillationdetectors.
HencetheinputpolarityoftheamplifierinGR611M(I)istobeselectedforPOSITIVE.RequiredLVsupplyof-12Vfor
thescintillationdetector,isdrawnfromtheGRSrearpanelthroughaLVcable.AlsotheHVbiassupplyforthePMTofthe
detectorassemblyisdrawnfromGRS,HVmodule.Preamplifierofthescintillationdetectorisachargeintegratingtypeof
preamplifier.
NucleonixSystemsofferswiderangeofNaIScintillationDetectorsofdifferent
sizesbothwithflat&welltypecrystals,tomeettherequirementsofwiderangeof
usersforGammarayspectrometrymeasurements.
Scintillationdetectorsofferedinclude1"x1",2"x2"&3"x3"NaIintegralassemblies
withbuilt-inpre-amplifiers.Thesedetectorassembliesgiveexcellentstability,
superiorperformance&goodresolutionintherangeof8.0to9.5%forCs-137.
Scintillationdetectorsof othersizescanalso beofferedagainstuserspecific
requirements
GammaReferenceStandardSetType:GS290consistsofasetofFIVEGammasources
evaporated&sealedon25mmdiax5mmplasticdisccoveringSIXphotopeak
energiesintherangeof2to5microcurie.Areferencechartforthisisgivenbelow.
Theaccuracyofthesesourcesisintherangeof+/-10%.Allthesediscsourcesare
enclosedinaboxmadeofpolishedwoodacrylicsheetandsupplied.
GAMMA REFERENCE STANDARD SET
TYPE GS 290
LEAD CASTLE FOR SCINTILLATION DETECTOR -LS 250
Thisconsistsof40mmleadshieldingcylindricalringsassembledaccordingtothedetector.Thereisaprovisioninthe
bottomringthroughwhichsystemconnectionsaregiventothedetector,whichisplacedintheleadshield.
Thetopringhasaholdingknobthroughwhichsamplecanbeloadedontothescintillationdetector,andthiscloses
theleadcastlefromtopside.
1-Inchdetector(8leadassemlingparts) 2-Inchdetector(9leadassemblyparts) 3-Inchdetector(10leadassemblyparts)
Isotope Energy Nominal Half
MeV activity life
Co-57 0.123 2-5Ci 273Days
Ba-133 0.36 (Main) 2-5 Ci 7.5Years
Na-22 0.511; 1.280 2-5Ci 2.6Years
Cs-137 0.662 2-5Ci 30Years
Co-60 1.17;1.33 2-5Ci 5.3Years

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NUCLEONIX SYSTEMS PVT LTD
CHAPTER - III
FRONT PANEL & REAR PANEL CONTROLS
FRONT PANELS AND INDICATIONS
FRONT PANEL CONTROLS AND INDICATIONS :
POWER ON SWITCH :
This is a miniature ROCKER switch which is used to power the unit. When the switch is put ‘ON’ the mains AC
power, is made available to the unit.
EHT (0-1500V) :
This is knob or ten turn dial to be rotated in the clockwise direction for increasing HV which is applied to the
Scintillation Detector, through a rear panel connector. Current HV value is indicated on the LCD dot-matrix display.
INTELLIGENT KEY PAD:
(a) PROG key button : This key is an important one which facilitates the user to programme the operation of
the instrument for different modes / conditions. More details are covered under "OPERATING INSTRUCTIONS"
in CHAPTER IV.
(b) START key button : This is used for starting of acquisition and printing, once all the programme parameters
have been set.
(c) STOP key button : This key can be used to terminate acquisition and printing whenever required. In the
normal course acquisition will stop automatically at the end of preset time and the data printing will stop
once the end serial number setting for printing has reached.
(d) INC/DEC key button : These keys are used while setting the programme parameters to increment and
decrement a value or to change the option selected to another value available.
(e) STORE key button : This key is used for storing the readings or data values in the following way, in the
manual mode of storing only.
At the end of acquisition for a preset time if user presses this button, data counts and with or without EHT will be
stored and the Sl.No. in the display increments to the next value.
In CPS/CPM modes the current CPS/CPM is saved on pressing this button.
OPERATIONAL CONTROLS OF FRONT PANEL
GAIN COARSE : Rotary control to vary the gain of the amplifier in hree steps viz. 1,2,4,8,16 and
32
FINE : A ten turn helipot control to provide continuous variation in the gain of the unit.
MODE (Switch) : Three way rotary control to select any one of the three modes of SCA operation
INT : In the integral mode the pulses of amplitude exceeding the base line (LLD)
setting will be made available at the output. ULD is ignored in this mode.
NORMAL : In this mode of the upper level and the lower level helical potentiometers are
independently variable from 0 to 10 V and an output is generated for pulses
analysed between these two levels. This mode is useful for wide window
applications.

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NUCLEONIX SYSTEMS PVT LTD
WINDOW : In the "Differential" mode the unit operated as a high resolution narrow window of
1 volt analyzer. Therefore pulses exceeding the base line setting (above LLD)
and within the window setting will be available at the output. In this mode LLD is
called as BASE LINE.
LOWER LEVEL DISCRIMINATOR : Ten turn potentiometer to vary from 0 to 10V
UPPER LEVEL DISCRIMINATOR / WINDOW : In 'NORMAL' mode this control is called ULD and this gets
triggered when the input pulse height is above the ULD setting. Dial corresponds to (0-10V) for ten turns. SCA
output is allowed if the input pulse height is below the ULD setting.
In 'WINDOW' mode this control is called WINDOW and ten turns variation corresponds to (0-1V) i.e., one turn is
equal to 100mV window. WINDOW is usually set to one tun (100mV) for scanning of an istope for its energy Vs
Countrate output. This window always overrides on the baseline.
NORMAL MODE OF ANALYSIS : This mode of operation is recommended when the user wants to count a wide
energy band of any isotope. Both LLD & ULD corresponds to (0-10V) for ten turns and user can bracket the region
of interest and count the sample. In this mode SCA gives output for each of the input pulses lying above LLD and
below ULD.
INT MODE OF ANALYSIS : This is integral mode of operation SCA generates output for all the input pulses just
above the LLD threshold. It ignores the ULD setting. Any application requiring this kind of situtation, user can set
to this mode.
WIN MODE OF ANALYSIS : This mode of operation is recommended when the user wants to calibrate the
Gammaray spectrometer or when one would like to scan the gamma spectrum of an isotope or when wants to
counts for a narrow band of energies.
In this mode LLD is called 'Base line' and ten turns corresponds to (0-10V). ULD is called WINDOW & ten turns
corresponds to (0-1V). That means each turn corresponds to 100mV Window. In this mode window overrides
(sits) on the baseline and all the input pulses above baseline and within the window set are counted. That is SCA
gives output for pulses between (BASELINE) and (BASELINE+WIN).
e.g. If baseline is at 1.0V (Dial at 1.0) & WIN dial at 1.0 (100mV window). For input pulses above 1.0V but below
1.1V, SCA output is generated.
LCD DOTMATRIX DISPLAY :
This is a 20 X 2 alpha numeric LCD dotmatrix and responds to all the commands from the keypad and displays
programme parameters, data counts, preset and elapsed times etc,.
REAR PANEL CONTROLS AND INDICATIONS :
TO PRINTER (Optional) : This is a 25 pin D-female connector through which one can connect a printer (with
centronics interface cable) for direct printing of data.
SERIAL PORT (RS232) (Optional) : This is a circular I/O connector having RS232 compatible signals for serial
data communication to a P.C. Under software control from a PC, the stored data reading from this unit can be
downloaded into PC.
MAINS SOCKET : This is a three pin socket, where mains cord is plugged & 230V, AC, 50Hz is applied.
FUSE : AC mains fuse provided to protect the transformer & secondary side circuits in case of over load condition.
5PIN I/O TEST SOCKET : All LV voltages have been brought out onto this as test points for checking low voltage
supplies.
HV OUT : This is a UHF socket from where HV output is taken to scintillation detector.
LV OUT : This is 5 pin I/ socket from where LV supply to scintillation detector pre-amplifier is taken.

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NUCLEONIX SYSTEMS PVT LTD
When we switch on the unit, the display will show up,
CHAPTER - IV
OPERATING INSTRUCTIONS
4.1 INSTRUCTIONS ON INTELLIGENT KEYPAD COMMANDS
for 3 Sec.
GAMMA RAY SPECTROMETER
for 3 Sec.
NUCLEONIX
SYSTEMS
This signifies that by default "acquistion
is in preset time mode". Because in
majority of the situations counting is done
for a preset time set.
If you want other modes of acquistion
such as CPS (Counts per second) or CPM
(Counts per minute) then press s or t
keys to select required mode or else
proceed as follows. If ACQ MODE is
required by PR. TIME then, skip the above
selction and prodeed as given below.
4.1.1 ACQUISTION MODE SELECTION
By default, display changes to,
ACQ MODE HV
PR.TIME XXXX
This always displays the current HV.
We can vary the HV by using helipot
knob on the front panel. As you
increase the knob in clockwise
direction HV increases. This is the
HV that is applied to G.M detector.
4.1.2. PRESET TIME SETTING
By pressing PROG key, display changes to,
This displays the previous preset time for counting. We can change the preset
time by the following way.
PRESET HV
TIME XXXX XXXX

Cursor position
sKey can be used to increase the value at the cursor position.
tKey can be used to shift the cursor position to the left.
>

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NUCLEONIX SYSTEMS PVT LTD
4.1.4. LABLE ASSIGNMENT FOR A DATA READING
Lable assignment is required and will be quiet useful for Researchers and Health physicists who may be
counting Beta/Samples or research samples. They will record background count, a reading with standard
source and followed by this number of readings with different samples. So, a feature for lable assignment has
been added in the micro controller software,
BG = Background
ST = Standard
SP = Sample
"SAVE? (PROG)"
This signifies that the set (programmed) parameters and their values are to be saved for operation of the
equipment. User can save the parameters by pressing s or tkey. If these parameters are not saved,
system will take and work according to the earlier programmed parameter.
Once programme parameters are saved user will find the display as
* Now steps (4.2.3), (4.2.4) & (4.2.5) as given below can be skipped by ** Normal users. One can keep
pressing "PGROG" key till you find
4.1.3. NUMBER OF READINGS
This displays the number of Readings taken during acquisition and also displays the HV
By pressing PROG key again display changes to,
READINGS HV
XXXX XXXX
By pressing PROG key, display changes to,
Before acquisition for each reading lable is to be assigned. If same lable is to be continued after a
particular assignment, then user need not do any thing, the same lable will continue till such time one
changes it.
LABLE XX HV
XXXX
XX :
Lable can be changed by using s or t keys, options are SP (Sample), ST
(Standard), BG ( Background).

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NUCLEONIX SYSTEMS PVT LTD
By default '1' is displayed. Number of iterations can be changed by using s
or tkeys.
Iteration programmability is another useful feature that has been provided. Sometimes user may like to
iterate a reading 2 or 3 times. The system allows this and it displays averaged reading only, at the end of
two or three iterations. Acquistion for iterations once initiated will go till all the iterations are completed.
Users intervention is not required.
By pressing PROG key, display changes to,
4.1.5. ITERATION PROGRAMMABILITY FOR A READING :
ITERATION HV
X XXXX
4.1.7. RECALL DATA READINGS
This is a very useful feature that has been provided in this unit. At the end of storing/saving of a set of
readings, this feature will enable the users to recall the readings on to the display, from the Sl.No. set in
the "RECALL" mode.
By pressing PROG key, display changes to,
Recall serial number can be changed by s or tkeys.
Sl.No. No. of counts
RECALL SP
XXXX XXXXXX
SAVE?
To save the above parameters press s or tkeys
"OK" will be displayed on saving of parameters (PRG)
4.1.6. SAVING PROGRAMMED PARAMETERS
All the programmed parameters are to be saved by the user before he can start acquisition. Without
saving, the system will use the previous parameters for acquisition.
By pressing PROG key, display changes to,
SAVE ? (PRG) HV
XXXX
>
>
>

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NUCLEONIX SYSTEMS PVT LTD
4.1.8. END SL.NO. "DATA READING" FOR PRINT OPTION :
This option facilitates that user to Erase the memory completely
By pressing PROG key, display changes to,
ERASE MEMORY?
By pressing s or t keys we can Erase the Memory
4.1.10. FOR STORING DATA (AUTO OR MANUAL)
This option facilitates the user to store the Data automatic or manual
By pressing PROG key, display changes to
STORE (DATA) HV
AUTO XXXX
By pressing s or t keys we can change to AUTO or MANUAL mode
4.1.11. FOR STORING DATA (WITHOUT HV OR WITH HV)
This option facilitates the user to store the Data with HV or without HV
By pressing PROG key, display changes to
STORE (DATA) HV
WITHOUT HV XXXX
By pressing s or t keys we can store data with HV or without HV
4.1.9. FOR PRINTING DATA
By pressing PROG key, display changes to
PRINT? HV
DATA XXXX
Now connect the Printer and Press START to print the data.

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NUCLEONIX SYSTEMS PVT LTD
Menu Options
ACQ mode Pr. Time
CPS
CPM
Preset Time -----
Sl.No. (A/O) -----
Label
SP
ST
BG
Iteration 1 / 2 / 3
Save? (PRG) OK / skip
Recall -----
END NO. (PRINT) -----
PRINT DATA -----
STORE DATA AUTO
MANUAL
HV -----

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NUCLEONIX SYSTEMS PVT LTD
CHAPTER - V
PC COMMUNICATION (Optional)
Serial Data Communication software for downloading data Gamma Ray Spectrometer to PC can be provided
separately at extra cost. Necessary instructions for using this software have been provided in the file (in CD/
floppy).

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NUCLEONIX SYSTEMS PVT LTD
CHAPTER - VI
BLOCK DIAGRAM DESCRIPTION
Refer to the block diagram, given in the following page. It consist of Scintillation detector SD 151 or its equivalent,
Low Voltage, High Voltage PCB, Linear Amplifier PCB, Single Channel Analyser PCB & Controller PCB all these
PCBs are housed inside GR612. The Scintillation Detector connected to the main electronics unit is called as
Gamma Ray Spectrometer. This unit is essentially used for studying the Gamma Ray Spectra of Gamma isotopes.
SCINTILLATION DETECTOR
It consists of a Sodium Iodide crystal optically coupled to a photomultiplier. It has got three connectors, UHF,
circular I/O or Minihex & BNC connector. The high voltage (operating voltage) required for the detector is fed from
the HV PCB and is connected to the UHF connector. Minihex / 5 pin I/O connector is used to feed in the low
voltages to pre-amplifier from rear panel of GRS. The output of the detector is given to the linear amplifier input
through a BNC cable. Scintillation detector of NUCLEONIX make or its equivalent can be connected to NUCLEONIX
Gamma Ray Spectrometer electronic unit.
LOW VOLTAGE PCB
Low Voltage PCB receives secondary, Voltage Outputs from the transformer and generates the following +15V, -
15V, +24V, +5V which are used by various circuit PCBs. All these supply voltages are generated using 3 Terminal
regulator ICs.
HIGH VOLTAGE PCB
It will generate 0 to 1500V. It has got HV out (UHF connector) and the ten turn dial / helipot for changing the EHT
continuously from 0 to 1500V. It can deliver upto a maximum current of 1mA. Line & Load regulation is better
than 0.001%. HV indication is provided on a 20x2 Dot Matrix Display. It is designed using a DC to DC converter
type of circuit.
Output from the HV PCB is fed to Scintillation Detector through a UHF cable for biasing of the detector.
Typically detector bias to scintillation detector can be from 600V to 900V.
SINGLE CHANNEL ANALYSER
Single Channel Analyser receives the input from Pulse Amplifier output. SC PCB essentially scans the input
pulses for differential pulse height analysis and givesout TTL output pulses for the windowed pulses. Output from
SCA PCB is fed to Controller PCB for counting purpose.
COUNTER TIMER PCB
Controller PCB can count the events for a preset time. Elapsed time and counts are indicated on the 20x2 LCD
displays. Input can accept input pulses of POS or NEG polarity of unipolar / bipolar or TTL pulse.
Integral GRS Front Panel has keypad buttons for operation and is designed around a microcontroller. It can
acquire data in three modes of operation namely
a. Preset Scaler b. CPS c. CPM.
Readings upto 1000 can be stored and recalled back onto the display. Further unit has built-in printer port for
direct data printing and serial port for downloading of readings to PC.

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NUCLEONIX SYSTEMS PVT LTD
L.V
EHT
INPUT
H
V
(0-1500V)
A
M
P
L
I
F
I
E
R
S
C
A
C O U N
T
E
R
T
I
M
E
R
Power Supply PCB
+/-15V, +24V, +5V
LV Socket (on rear panel)
Printer
Personal
Computer
Optional
BLOCK DIAGRAM OF GAMMA RAY SPECTROMETER (INTEGRAL MODEL)
TYPE : GR612
IN OUT IN OUT
SCINTILLATION
DETECTOR
230V, AC 50Hz
Centronics Port
RS232C
Integral GRS enclosure
>
>
>
>
<
>
>
<

18
NUCLEONIX SYSTEMS PVT LTD
CHAPTER - VII
SYSTEM INTERCONNECTIONS / INTEGRATION
For system interconnections, please refer to the interconnection table given on the following page.
The other optional accessories that can be connected to this system are printer which can be used for printing
data counts stored. Also a PC if user wants to download the data into PC.
Essentially the following cables are used :
1. UHF to UHF cable 01 No
2. LV cable (5 pin I/O connector Cable ) 01 No
3. Signal cables (BNC to BNC) 03 No
Required for interconnection.
OPTIONAL CABLES
4. Printer cable 01 No
5. Serial port cable 01 No
Usually the Gamma Ray Spectrometry System GR612 is shipped / despatched in ready to use condition.
System interconnection are to be made as per the table given on the following page, which include connections
between scintillation detector to the main counting system & connections on the unit itself.
GAMMA RAY SPECTROMETER INTEGRAL SYSTEM INTER CONNECTION DETAILS
S.No.
Type of Cable
Signal from
Signal to
01. UHF to UHF high voltage cable
(1.5 metre length)
EHT output from UHF socket
on rear panel of GRS
Scintillation detector
UHF socket
02. LV cable with two end Circular
I/O to Circular I/O connector.
LV signal on R.P of
Instrument
LV signal to Scintillation
detector Circular I/O
Connector.
03. Signal Cable (BNC to BNC) 1
or 1.5 meter long
Scintillation Detector (O/P
BNC)
AMP Input BNC
recepticle on F.P / R.P
of Instrument
04. Signal Cable (BNC to BNC) 0.3
or 0.5 meter long
AMP OUTPUT BNC to SCA IN (BNC)
05. Signal Cable (BNC to BNC) 0.3
or 0.5 meter long)
SCA OUT (BNC) to COUNT IN (BNC)
06 A.C mains cord 230V, AC, 50Hz, Power
socket
Instrument socket on
R.P
OPTIONAL CONNECTIONS
07.
25 pin D-25 pin D cable
Rear panel GRS
To printer
08. 3/5 pin circular I/O connector to 9/25
pin D-connector
Rear panel GRS To PC Serial Port

19
NUCLEONIX SYSTEMS PVT LTD
CHAPTER - VIII
MAINTENANCE
OPERATING INSTRUCTIONS
Before using the GAMMA RAY SPECTROMETER (GR612) system for Normal testing user has to follow
the instructions given below.
1. Make sure all interconnections are made properly. All dials, rotary switches, rocker switches, BNC
sockets are in good condition.
2. If any damage happened to the system, report the matter immediately to:
Customer Support Division
NUCLEONIX SYSTEMS PVT. LTD.
Plot No. 162 A & B, Phase II
I.D.A. Cherlapally,
Hyderabad - 500 051. for further action/help
Ph : 91-040-27263701 FAX : [phone]
e-mail : [e-mail]
3. Before switching ON the system keep all the controls to default settings as mentioned below.
a. i. ON Rocker switch to OFF position
ii. HV adjust knob to complete anti-clockwise direction (0 volts)
b. i. COARSE GAIN switch to ( )
ii. Fine gain to 'minimum'
iii. Polarity to 'POS' (AMP IN)
c. i. MODE to 'WIN'
ii. LLD/Baseline dail to 'min' position
iii. ULD/Window dial to 1.0 ( = 100mV)
d. HV dial to minimum to start with.
4. Now place the Scintillation detector closely onto the left of the Integral Gamma Ray Spectrometer unit. If
Lead Castle is ordered with this, then assemble the Lead Castle by placing the Scintillation detector
inside the lead shielding (for details on assembly refer to the Lead Castle LS240 folder/manual).
5. Switch On the system, apply the high voltage to the detector by rotation the HV knob / ten turn pot in the
clock wise direction.
6. Place a source ( Cs_137 ) on top of the Scintillation detector, observe the Amplifier output in a good
oscilloscope(60 MHz/100 MHz) in 1V / DIV sensitivity.
7. Now adjust the 'Gain' (reduce if required) or slightly the fine gain knob dial such that the photopeak
amplitude (ht) of CS-137 as observed in the oscilloscope is in the range of 2.5V to 3.0V. (For this output
of amplifier is to be fed to oscilloscope)
8. Now restore AMP output connection to SCA INPUT and scan for the gamma spectrum of Cs-137 isotope
by taking the readings. For this vary the BASELINE (LLD) control dial in steps of 10 small divisions
(which is equal to 100mV) starting from 0.00, 0.10, 0.20, 0.30...... etc., one would observe peak counts,
between 2.5V & 3.0V baseline setting.
Here for each SCA setting counts are stored in EEPROM of Controller PCB for a preset time of 10 to 50
sec or as desired by user. For programming and using the keypad refer to command instructions in
detail. PRESET TIME is to be selected such that countrate is fairly in the range of 5000 count/preset time
near peak (approx).

20
NUCLEONIX SYSTEMS PVT LTD
9. From the above readings stored/acquired user can findout the resolution of the Scintillation detector, for
Cs-137 (Refer to Chapter IV(b) for more details and one can find linearity of the spectrometer by placing
other isotopes and counting)
Once the above is carriedout the spectrometer is calibrated and is ready for use.
At this stage user will have information on Energy Vs Baseline voltage from the linearity graph.
10. Now user can place his actual sample for counting.
a. If it is a known energy then select the LLD & ULD & MODE (either NOR for wider energy band
counting, WIN mode for narrower energy band counting) approprately and do the sample counting.
b. If it is unknown energy one has to scan the entire range by operating in WIN mode then identify
the energy band, after which actual sample counting could be carriedout.
11. This system has the facility for connecting to a printer for data printing and also data readings could be
downloaded into PC.
Also the readings could be saved at the end of each acquisition and recalled back on to display for
visualisation.
MAINTENANCE
When faults occur only an experienced technician should be entrusted with the servicing work.
Whenever a fault occurs which is beyond the local services facilities the matter should be referred 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, 32918055, 32914548
FAX : [phone]
In all correspondance regarding the GRS , kindly mention the serial number along with month/year of
purchase.
PREVENTIVE MAINTENANCE :
The following preventive measures should be taken at regular intervals.
1. Keep the unit free from dust and moisture as excessive amounts of those will result in surface leakage
paths interfering with the functioning of the circuits. Clean compressed air should be used to blow off the
dust.
2. Ensure that the printed circuit is firmly seated in its connecting socket. Press it in position if necessary.
3. Visually inspect the components for deterioration. Burnt out or heavily overloaded resistors will show a
charred or tarnished look. Leaky or highly deteriorated electrolytic capacitors are some times characterised
by a corroded appearance. Incase a burnt out or over loaded resistor or burnt or burntout tantalum
capacitor is detected they are to be replaced.