Counting System
 Para Electronics offers radiation monitoring instruments :  Radiation Monitor
 Special Unit for measurement of Radioactive Contamination in Steel and Other Metals | NIM Modules
 Radiation Survey Meter (Analog / Digital) | Contamination Monitor | Spectroscopy
 Area Gamma Monitor| Portal Monitor | Laundry Monitor| Data Acquisition
 Scrap Monitor |Teleprobe Surveyor | Foot Monitor | Alpha Particulate Monitor

Special Projects
         
 PCM-3 : Portable Contamination Monitor, with Pancake Type GM Detector for Contamination Measurement

Portable Contamination Monitor, Model PCM-3, is a micro controller based, portable ,light weight, battery operated instrument for measurement of environmental / field dose rate of gamma ray and x-ray radiation. It is useful for Health Physics applications in Nuclear Power Plants, Nuclear Medical Centers and Radio Isotope laboratories. Model PCM-3 employs external GM detector for direct readout of either dose rate in uR/hr, contamination in Bq/gm, Count Rate in CPS or CPM. With Pancake type GM tube, Model PCM-3 is useful for measurement of Contamination in Steel, other metals and alloys.

This pancake type GM tube is supplied externally with 1 meter long cable. Portable Radiation Survey Monitor, Model PCM-3, works on 6V rechargeable Ni-MH batteries. A mains operated charger is also supplied with PCM-3 for keeping the batteries charged. Typical operational battery charge life is 8 to 10 hours of continuous use.
 

Selection of Material, either Aluminum or Iron or Cast Iron or Copper is provided. User can enter material thickness between 0.1 mm to 199.9 mm. Backlit ON/OFF key allows user to turn OFF the backlit to enhance the battery charge. Two line LCD display is used as interactive Menu for displaying Dose Rate in µR/Hr or Contamination in CPS or in Bq/gm and also to get the type of material and its thickness. Calibration of PCM-3 is done at factory, using Co-60 radioactive sources supplied by BRIT, Mumbai. A small check source (Co60) can be supplied as an option at extra cost. Dose Rate Alarm setting is also provided to activate an LED indicator when the incident dose rate value exceeds the set alarm value.

Model PCM-3 is supplied with standard accessories like battery charger, operating manual and carrying case.
 

Specifications :

 Dose Rate Indicator
  Measuring Ranges : Contamination : 0.01 - 100.00 Bq / gm
Dose Rate : 0 - 20,000 uR/Hr
Count Rate : 0- 10,000 CPS 
 
  Detector   : Pancake type, externally mounted with 1 meter long interconnecting cable
  Radiation Detected   :  Alpha, Beta (without Shutter), Gamma/X Rays
  Accuracy :
± 20% of Range
  Energy Range : 100 KeV to 2 MeV (Gamma)
  Time Constant   : 1 second for CPS and 10 second for Bq/gm or µR/Hr
  Material   : Aluminum, Copper, Iron and Cast Iron
  Material Thickness : 0.1 to 200 mm
  Menu Display : 16x 2 Characters LCD for display of reading and other parameters
  Dose Rate Alarm : Settable in µR/Hr through out the range
  Alarm Indication : Illuminated RED LED
  Diagnostic Output : No pulse indication, Low battery indication
  Audio Output   : Chirper output proportional to incident dose rate
  Backlit  : User Selectable ON or OFF
  Battery / Charger : 6 V Ni-MH battery with mains operated charger
  Battery Life : More than 8 Hours per charging
  Dimensions : 140 W x 110 B x 50 H centimeters
  Weight : Approximately 500 gms
  Standard Accessories : Operating Manual, Carrying Case
  Check Source (Co60) : Optionally available at extra cost
  Warranty : 1 year from date of dispatch


 PRSM-1 : Portable Radiation Survey Meter

Portable Radiation Survey Monitor Model PRSM-1 is a micro-controller based, portable battery operated instrument for measurement of environmental/ field dose rate of Gamma and X-ray radiations. It is useful for Health Physics applications in Radioisotope Laboratories, Nuclear Power Plants, Nuclear Medical Centers.

Model PRSM-1 employs an external GM detector for direct readout of either dose rate or counts for selected time interval.  It is powered by 4 nos. type AA pencil cells - carbon or NiCd type.

Audio Chirper can be turned ON or OFF as per users choice. Two line LCD display is used as interactive Menu as well as Dose Rate Display / Counts.

Specifications :

 Dose Rate Indicator
  Dose Rate Ranges : 0 - 200 mR/Hr (auto ranging)
  Accuracy : ± 20% of Range
  Energy Range :  100 KeV to 2 MeV
  Integration Time (sec) :
Fast  Meduim Slow
(1 Sec)  (5 Sec) (10 Sec)

  High Voltage
:
0 to + 1000 Volts at 0.1 mA internally settable
  Detector Probe : Halogen quenched GM Tube Type 712 or equivalent
Sensitivity : 18 CPS at 1 mR/Hr, Operating Voltage 500 - 900 Volts
Housing : Size - 24 mm Dia x 110 mm Long, Aluminum tube Powder epoxy coated
  Display  : 16 x 2 line LCD for Dose Rate Indication
  Backlit : User selectable ON or OFF
  Chirper : Audio proportional to incident radiation rate. User selectable ON/OFF
 General
  Dimensions : 140 W X 110 B X 50 H mm
  Weight  : Approximately 460 gms
  Battery  : 4 nos of 1.5 V Pencil Cells type AA (30 Hrs of operational life) or rechargeable NiCd Cells Optional
 Accessories

  Battery Charger

: 240V AC, 50 Hz mains operation

 

 
 PRSM - A : Para Radiation Survey Monitor (GM Tube Based) 

 

 

Para Radiation Survey Monitor Model PRSM-A is a battery operated portable instrument designed for survey application in Nuclear Power Plants, Environmental Survey Labs. Etc. 

Model PRSM-A has analog meter display for indication of Dose Rate or Contamination Level. Beep Rate proportional to input dose rate can be turned ON or OFF.

Typical Dose Rate ranges are 2, 20 and 200 mR/Hr however other ranges also can be supplied. The Range Selection switch enables user to select appropriate range. In Contamination Monitor mode, the analog display indicates Counts per sec. Typical ranges are 50, 500 and 5000 CPS. Dose Rate or Contamination Monitor modes are switch selectable.
 

PRSM-A, uses GM tube as radiation detector. GM Tube can be housed inside the instrument or can be supplied in an SS enclosure (with shutter arrangement for beta measurements) with suitable cable.

PRSM-A, works on a 9 V battery. Typical battery life is more than 15 hours if Alkaline battery is used. Battery charge level is indicated on the meter dial, for 3 seconds whenever the instrument is turned ON.

Specifications :

  Radiation Detected :  Beta/Gamma (depending on the GM tube type used)
  GM Detector   :  Internal or External with 1 meter long cable 
  Detector Housing :  As required
  Ranges :  Dose Rate : 0 - 2, 20, 200 mR/Hr
 Contamination : 0 - 50, 500, 5000 CPS
  Range Selection :  x 1, x 10 , x 100
  Indication :  Analog Meter Dial graduated in above ranges
  Audio Output   :  Beep Rate proportional to dose rate (can be turned ON/OFF)
  Battery Operation   :  9 V Alkaline battery (Dura Cell or similar) 
  Battery Life :  > 15 Hrs
  Weight   :  Approximately 650 gms
  Supplied with :  Leather carrying case with shoulder strap & Instruction Manual
   

 

 

 PCM-2 : Contamination Monitor

 

 

PCM2, Contamination monitor is used for measurement of radioactive contamination in Nuclear Power Plants, Nuclear Medicine Centers. This instrument is ideally suitable for scanning material, tools, clothing, personnel etc. It is a mains operated unit & includes nuclear detector (GM tube) assembly probe and processing electronics. 

Specifications:

 Detector Assembly 
  Detector :  Thin walled GM counter 
  Housing : Chrome plated brass tube with shield to prevent beta detection 
Size : 270 L x 32 D mm
  HV supply : 0 to 1000 Volts @ 1 mA internally set at detector operating voltage 
 CRM and Failure Alarms
  Alarms : Beeper and Red Flasher ON when count rate exceeds preset level
  Set Point Adjustment : Adjustment over entire range.
  Reset : Push switch to clear alarm condition 
  Failure Alarm : Red Flasher alarm is continuously ON if no pulse is detected within 60 secs 
 Count Rate Meter
  Linear CRM : Three ranges of 0-10, 100 and 1000 CPS switch selectable 
  Accuracy :  ±5 % of full scale 
  Display : Taut band 96 x 96 mm square panel meter, 270° deflection pointer movement 
 
    *  (Other GM deyectors also can be offered as option)

 

 
 PAG-3 : Para Area Gamma Monitor (GM Tube Based) 

 

 

Para Area Gamma Monitor Model PAG-3 is a micro-controller based; economical, stand-alone, mains operated instrument that uses GM tube as nuclear radiation detector. Necessary electronics & high voltage supply are housed in the equipment. PAG-3 has dose rate range 0 to 100 mR/Hr. Audio and visual alarms turn ON if the dose rate level exceeds the set value. Alarm relay change over contact is provided for external control or indication.

This unit is supplied with an Auto ranging direct reading 3+1 digit 7 segment LED display for dose rate, preset alarm level and information related to instrument status, self test etc.

PAG-3 is ideally useful for health physics applications in radioisotope laboratories, nuclear reactors, nuclear power plants, environmental survey labs, etc.

Alarm Level setting, Dose Rate calibration can be performed by using the two keys namely INC/DEC and MODE Key. Optional key lock feature restricts the editing only to the authorized personnel preventing the other persons from tampering the calibration or changing the Alarm parameters.

Normal operating condition is indicated by illuminated large area Green LED. Red Flashing, large area LED accompanied by audio alarm indicates the dose rate alarm condition. On pressing the acknowledge key, the instrument will return to normal condition or may continue to flash alarm condition as the case may be. HV status is indicated by HV status indicator LEDs.

Status Indication 

Normal 

Steady Green LED 

Dose rate alarm 

Flashing Red LED & Audio Alarm

On Acknowledge 

Steady Red LED if dose rate alarm level persists

HV Normal 

Green LED ON 

HV fail 

“EHT FAIL “ message on3+1 digit 7 segment display 

No pulse / detector Fail 

“Tube FAIL “ message on 3+1 digit seven segment display. 

PAG-3 also performs self-diagnostics for HV failure, detector, counting, and memory electronics failure on power on.
Detector 
GM detector probe can be mounted internally or connected externally to the monitor. The external GM Tube is housed in suitable, airtight S.S/ Aluminum shell. Connecting cable length between the detector and the monitor will be 10mtrs (typical).

Energy compensated GM tube or User specified GM tube also can be supplied with PAG-3. 
Options

Specifications :
 

  Monitor
  Design :  Micro-controller based
  Display   :  Auto ranging direct reading 3+1 digit 7 segment LED display 
 For dose rate, Alarm level, status indication and self test 
  Range :  0.1 mR/Hr to 100 mR/Hr
  Response time   :  Response time is variable between 20 Secs to 1 Sec  
 depending on dose rate
  Accuracy   :  +/- 15 % through the range
  Alarm range :  0.1 mR/Hr to 99.9 mR/Hr
  Front panel Keys   :  2 keys provided on front panel to set alarm level, 
 Acknowledge and auto calibration
  Indication   :  Large Area Green LED for Normal Indication.
 Large Area Red Flashing visual with audio alarm for dose rate 
 Or Bright Red visual for No pulse alarm / detector fail alarm. 
 HV fail LED / HV normal LED indication 
  Outputs :  2 Change Over potential free relay contacts
  Construction   : Wall mounting type
  Dimension   :  270 L x 120 D x 200 H mm
  Options :  4 to 20 mA and or 0-5V Full Scale Output, RS-232 / RS-485 with data logging software
   
  Detector ( GM Tube) 
  Detector   :  GM tube suitable for 0 to 100 mR/Hr range
  Radiation detected :  Gamma
  Detector housing :  Internally mounted. 
 External detector ( Optional)
 The GM detector probe will be located external to the monitor.
 It shall be housed in suitable, S.S/ Aluminum shell. 
 Connecting cable between the detector and the monitor will be 
 10mtrs (typical)
  Operating voltage :  HV supply is factory set as per GM Tube specifications
     

*  (Other GM deyectors also can be offered as option)


 
 Portal Monitor 

 

 

Portal Monitor System offered by Para Electronics is intended to be used for detection unauthorized movement of nuclear material by personnel crossing the plant boundaries. The detection is based on Gamma Radiation emitted by nuclear material being carried by the personnel. Portal Monitor is designed for 24 hours continuous operation.

Portal Monitor can be supplied with various types of detectors GM Tubes, Pan cakes, Plastic Scintillators or NaI(TI) detectors. Each type of detectors have certain advantages over other type with respect to detector efficiency, ruggedness, ease of operation and the cost. Adequate lead shielding can be provided for the detectors to improve minimum detectable activity.

Settable response time, background subtraction facility, microcontroller based counting, Audio/Visual Flasher alarms are some of the standard features of Portal Monitors.

Number of detectors, mounting of detectors, lead shielding, type of detectors are configured according to the customers/users specifications. Typical configurations are 6 nos of NaI(Tl) detectors or 6 nos of Plastic Scintillators or 10-150 GM tubes with associated electronics for the basic structure of Para Portal Monitor.
 

Automatic occupancy detection, fast response time to detect the increase in counts over background counts, enables the user to set these parameters of his choice. Remote alarm indication and acknowledge are also provided for the Portal Monitor System.

Para Electronics can supply a modular system consisting of detectors, HV supplies, pulse processing unit and the counting system. Audio/Visual alarms, potential free relay contacts are provided for external alarm indication.

Portal Monitors can be supplied in different configurations. Para Electronics can supply any desired configuration as per user's requirements. 

Typical Specifications :

  Number of Channels   : 8
  Input for each Channel   : TTL pulse of width 1 µsec or greater
  Preset Time   : 1 to 999 Seconds (software settable)
  Alarm Counts for channel   : 1 to 65000 (software settable) 
  Alarm Operating Logic   : 1,2,3,4,5,6,7,8 out of 8 (software settable)
  Maximum Counts per 
  Preset Time per Channel  		 :   65000 
  Active Alarm Channel 
  Indicators 		 : LED indicators
  Alarm level setting   : a) Above Background Mode 
b) Absolute Counts Mode
  Alarms   : Red Flashing Visual Alarm Potential free Relay Contacts
 Mechanical 
  Enclosure   : Aluminum Powder Coated Frame 
  Dimensions   : 310 L x 130 H x 220 W mm 
  Weight  : Approximately 3 Kg
  Power : 240 V (+ 10 %) AC, 50 Hz

 

 
 Laundry Monitor

 

Laundry Monitor is developed for manual monitoring of beta/gamma contamination of clothing like lab-coats (aprons), boiler suits, hand gloves or shoe covers used by personnel in radioactive area in nuclear power plants/research labs. Normally these clothing are checked for contamination and segregated into active and non-active lots before sending out of the plant for processing by plant laundry. It is a practice to check inward laundry also to confirm whether the cloths are non-contaminated before use.

Para Electronics has supplied laundry Monitors of different configurations i.e. BOX type or FLAT BED type. Both these configurations use energy compensated GM Tubes. However beta/gamma sensitive tubes also can be supplied. 

BOX Type Laundry Monitor

In BOX Type Laundry Monitor the system has Detector Head (measurement zone) adequate for type of laundry to be monitored.  The measurement zone is covered by set of thin walled GM Tubes to measure beta/gamma radiations from the laundry. Relevant processing electronics is housed around the measurement zone. Suitable LED indicators are provided around the measurement zone to indicate zonal contamination level or hot spots of the laundry being monitored. Alarms and contamination level is indicated on contamination monitor (main measuring instrument) in CPS value in accordance to the user specifications. The size and shape of the measurement zone, contamination level ranges and background activity subtraction can be suitably modified to any different requirements.

Specifications :
    Detector Head

  • 18 energy compensated GM tubes
  • 6 HV supply and front end
  • Electronic circuit PCBs
  • Contamination Monitor with Analog readout
  • 0-500, 5K and 50 K CPS ranges
  • Audio/Visual alarm
  • Beta Gamma sensitive tubes as option
  • Background subtraction ON or OFF
  • Compact, easy to use
  • No Pulse, high counts, count rate alarms
  • Analog 0 to 207 degree meter indication
  • 240V AC mains operation
  • Alarm Settings : 0 to 100% of range

Flat Bed Type Laundry Monitor

FLAT BED type design employs 24 GM Tubes housed in 12 SS trays with lead lining. Each tray has HV supply and counting electronics for two tubes. The output from each tray is sent to the main counter unit which houses 12 independent counters. Background subtraction, No pulse Alarm, MIMIC Display and Audio/Visual Alarms are the standard features for Laundry Monitor. Automatic sensing of the laid cloth is detected by photo sensor and the counting is activated. MIMIC display gives indication of high contamination zones.

Specifications :

  • 24 energy compensated GM tubes housed in 12 SS trays

  • Separate HV supply 6 and front end electronics PCB per tray

  • Micro controller based counter with set up and operate mode

  • 240V AC mains operation
  • Counts from each tray are counted seperately
  • Audio/ Visual alarm
  • Alarm setting : 0 to 100% of range
  • Beta/ Gamma sensitive tubes as option
  • Background subtraction ON or OFF
  • MIMIC display for detection of high contamination zones

 

 
 Scrap Monitor 

 

 

Scrap Monitor Model PSM-1 developed by Para Electronics is to cater the requirement of monitoring scrap for possible gamma contamination. This Monitor employs 6 nos. of energy compensated GM tubes. These thin walled GM tubes will be mounted parallel to the length of the Scrap Monitor. The housing of these GM tubes can be moved vertically for a span of nearly 700 mm. It’s lower most position will be at 40 mm from ground level and the highest position will be at 300 mm .The output of these GM Tubes will be OR tied and will be fed to Scrap Monitor’s display unit. This display unit consists of Count Rate Meter, Audio / Visual settable alarms, facility to subtract background level. Count Rate Metering circuit has 3 Ranges namely, 0 to 500 CPS, 0 to 5000 CPS and 0 to 50000 CPS. The alarm level can be set between 0 to 100% of any range. Analog Meter with 2700 square dial will indicate the CPS level. The integration time can be set to either 1 sec or 5seconds. Alarm levels are indicated on the same meter by setting the band switch to appropriate position.

Contamination Monitor has a facility to subtract the background. It is possible to subtract the background upto 500 CPS. User can select background subtraction by setting background subtraction switch to ON position.

Typical Specifications :

 Detector Head

   
  Mechanical Dimensions   : Overall Dimensions :
700 W x 500 H x 500 D mm (approx)
Detector Housing with Stainless Steel Bottom :
700 W x 500 H x 100 D mm (approx)
  Detector(s) used   : Thin walled Halogen quenched GM Tubes with overall length 280 mm and diameter 28 mm
  No of GM Tubes   : 6
  HV Supply modules   : One HV supply module per 3 GM tubes 
  No of HV modules   : 2
  HV Output   :  Internally settable up to +900 V  
  Detector Head Output   : OR tied TTL output from all the GM tubes will be fed to the contamination monitor. All outputs will be effectively averaged over the integration time 6 core cable 3 meter long

 Display Unit (Contamination Monitor)
  Count Rate Ranges   : 0 to 500 CPS, 0 to 5000 CPS, 0 to 50000 CPS
Three switch selectable ranges
  Input   : TTL Input pulses from Detector Head
  Alarm Level   : Settable Alarm Level between 0 to 100% of selected range
  Alarm Level Adjust   : Single turn potentiometer screw driver settable mounted on rear panel User can set Alarm Level between 0 to 100% of
selected range
  Alarm Indication : Visual - RED flashing LED indicator
Audio – Audio Alarm
External – Relay change over contact
  Alarm Acknowledge : Front panel mounted push switch to reset the audio alarm. Visual alarm will switch off when the contamination level goes below the set value
  Integration Time : 1 or 10 seconds switch selectable
  CRM Indication : 100 mm x 100 mm square, 0 to 2700 Analog Meter
  Background Subtraction : 0 to 500 CPS settable by 10 turn helipot with graduated dial
 Mechanical 

 Detector Head 

   
  Enclosure   : Aluminum Powder Coated Box 
  Typical Dimensions   : 807 W x 850 H x 400 D mm 
  Trolley   Steel Frame with adjustable vertical height for detector head
  Vertical Height Adjustment   From 40 mm to 300 mm by a bevel gear arrangement
 Contamination Monitor    
  Enclosure   Aluminum Powder Coated Box
  Dimensions   310 W x 150H x 280 D mm
  Power : 240 V (+ 10 %) AC, 50 Hz Mains
     

 

Trey Up Position

Trey Down Position

 

 
 PTS-1 : Teleprobe Surveyor 

 

 

   

Para TeleSurveyer Model PTS-1 is a portable light-weight battery operated instrument for measuring radiation and for tracing gamma radioactive material or contamination. PTS-1 provides dose rate measurement in different units viz. CPS, R/Hr and mSv/Hr by front panel soft key. Wide measuring ranges from 1mR/Hr to 999.9 R/Hr or 1 µSv/Hr to 8640 mSv/Hr are auto-ranged. The response time is 2 to 50 secs inversely proportional to dose rate.

Analog and digital value of dose rate is displayed on a 64x128 pixel Graphic LCD. Analog display is dual decade bar graph like 0 to 100 % with 2% resolution. Large font digital display of dose rate value with selected unit is provided. Audio beep proportional to dose rate is provided. Dual GM tubes for low and high dose rate are housed in a detachable cylindrical enclosure at the end of telescopic probe to avoid damages during transportation.

An error-free reading, self-contained telescopic probe extendable upto 2 meters consequently increases safety factor from radiations source and facility for measurement in inaccessible places. The GM tube enclosure is detachable from the telescopic arm for easy portability and protecting detectors from damages during transport. Audio/visual alarms are provided for GM tube failure, HV failure or cable/probe discontinuity and re-charge battery. PTS-1 operates on built-in trouble-free Ni-Cd rechargeable battery pack. PTS-1 is supplied with mains operated battery charger.

 

 

Typical Specifications :

  Radiation detected   :  Gamma
  Range    Soft key selectable AUTO-RANGING in units CPS, R/Hr or mSv/Hr
 1 mR/Hr to 999.9 R/Hr, 1 µSv/Hr to 8640 mSv/Hr, 1 to 99999 CPS
  Detectors   :  Energy Compensated dual GM tubes with Auto switching
 Low Range 1mR/Hr to 800 mR/Hr          70003E by Vacutec or Equivalent
 High Range 600 mR/Hr to 999.9 R/Hr    ZP1301 by Centronic or Equivalent
 Housed in a detachable Al cylindrical enclosure
  Response   :  2 to 50 secs inversely proportional to dose rate in AVG mode
  Energy Response    ± 10 % for 100 KeV to 2 MeV
  Display   :  64 X 128 pixel Graphic LCD Display with on demand BACKLIT
 Digital :- Large Font digital display with dose rate Units
 Analog :- 0 to 100 % bar graph with 2 % resolution
 Soft Keys :- UNIT, AVG, SPK
 Battery :- Normal/Low Iconic indication
 LR/HR :- Iconic display Low or High Range GM tube in use
 Alarms :- No Pulse, Battery Low and Probe Discontinuity
 Audio :- Beeps proportional to pulse rate
 Calibration facility with Soft Keys
  Controls   :  Power ON/OFF , RESET, LCD Contrast, LCD Backlit ON
  Power   :   Analog 4.5 Volt Rechargeable built-in Ni-Cd Battery pack
 8 Hours continuous operation with backlit OFF
 External mains operated Battery Charger Unit provided
  Mechanical    :  Measurement and Display Unit of Elegant ABS Plastic
  - Size 85 W X 150 H X 30 D mm Black
 Telescopic detachable Probe Assembly
  - GM tubes Housing 30 mm dia X 175 mm long Cylindrical Aluminum Casing
  Telescopic Probe length
  - 830 mm fully Retracted
  - 1800 mm fully Extended
  Weight :  1200 gms
   

 

 
 PFT-1 : Foot Monitor 

 

 

Foot Monitor Model PFT-1 manufactured by Para Electronics is developed to detect the nuclear contamination on the shoes. This unit is designed around 4 nos of thin walled GM tubes (typ1 719) for detection of beta/gamma contamination on the bottom of the footware. A pulse from each GM tube is counted independently before all the counts are added together  to determine if the aggregate counts are below the set level. Counting time, Alarm level are user settable. Audio/Visual alarms are provided when the contamination level crosses the set limit. LCD menu display indicates the status of the contamination and is used for diagnostic purposes also. The detection of person's standing is done by the pulses from GM tubes.

GM tubes, 4 nos used in Model PFT-1 are surrounded by 6 mm thick lead shield. This reduces the background counts. Foot Monitor continuously counts the background counts and stores the latest background. These background counts are subtracted from the actual counts. Net counts are used fro alarm activation.

Typical Specifications :

 Detector Assembly
  Detectors   :  4 nos of thin walled GM tubes type 719 or equivalent
 ( 2 GM tubes per foot)
  Lead Shield   :  6 mm thick lead shield on five sides around the GM tubes
  S. S. Grill   :  On the top of the GM tubes
  Light Switches   :  2 nos to detect the standing of the person on the foot monitor 

 Counter / Alarm Assembly
  Electronics   :   Micro controller based counter with 16x2 Line character LCD
 menu display for counts and other messages   
  No. of Channels  :  2 with separate counters
  Timer   :  Settable between 1 to 99 seconds
  Alarms   :  Audio and Visual
  Alarm Setting    :  Settable upto 9999 counts/measurement
  Background Subtraction :  Selectable ON or OFF
 General 
  Dimensions   :  460 L x 470 W x 150 H mm 
  Weight  : Approximately 25 Kg
  Power : 240 V (+ 10 %) AC, 50 Hz (Single Phase)

 

 
 PAM-1 : Alpha Particulate Monitor 

 

 

Alpha Particulate Monitor Model PAM-1 developed by Para Electronicsconsists of following subsystems

  • Detector, Preamplifier, Filter Paper Holder

  • Instrument for data collection

  • Panel PC for display, operation control, data storage and communication

  • Vacuum pump

  • UPS

Complete system is assembled on a trolley. System consists of a detector, preamplifier with filter paper holder. Detector is PIPS or surface barrier type. Preamplifier is directly mounted on the detector. Active area of the detector faces the filter paper. Filter paper is kept inside the filter paper holder. PIPS detectors or surface barrier detectors are sensitive to light. While changing the filter paper, it is necessary to switch off the bias for detector and the supply of the instrument. This step can be avoided by using a mylar layer on the detector.

Preamplifier requires +12V and -12V supply. Detector bias voltage is around 30 volts. Multicore cable with one coaxial is used to carry the necessary voltage and the preamplifier output between the preamplifier and the instrument. 6 pin allied connector is used at the instrument end. Cable is directly soldered to PCB at the preamplifier end.

Power supply for the instrument consists of +5V SMPS for digital circuits. For +12 and -12V, linear supply is used. Inside the instrument, there is a power supply card and the MCA card. Necessary bias for the detector is generated on the power supply card.

Preamplifier output first goes to spectroscopy amplifier. Rise time of the amplifier output is 1.2 uS. Amplifier output is then given to 10 bit Wilkinson type ADC. Necessary signals for control of ADC are generated by the main controller C8051F340. This controller also handles the USB communication with the panel PC. Spectrum collected by 1K channel MCA is first stored in the internal memory of the PC. Then after every second, the spectrum is transferred to software package which runs on the panel PC. The spectrum collected by the MCA is displayed on the PC screen. Many other features like data storage are available in the package.

Mains supply is routed through the spike guard. Vacuum pump is connected on the mains line whereas the instrument and the panel PC are connected to the UPS as shown the block diagram. UPS capacity is 500 VA. This gives backup time of at least 1 hour in case of power failure.

Vacuum pump capacity is 100 LPM. Normal suction rate through filter paper is 40 LPM. This generates back pressure on the pump and results in pump failure. Bypass valve is connected on the suction line of the pump as shown in the diagram to avoid the back pressure on the vacuum pump.

Specifications :

Air Monitor Detection Unit

1K MCA based Unit for detection of Alpha particles  
  Supply                              :  230V, 50 Hz Mains
Radiation Detection          :  4.2 MeV to 8 MeV
      System Resolution             :  300 KeV
       Display                             :  In CPM and Bq/m3
Pre Amplifier
  Detector Type                   :  Ion Implanted Silicon Detector
Resolution                        :  20 KeV in Vacuum

       Active Area                       :

  450 mm2

       Bias Voltage                      :

 +30 Volts
Pre Amplifier
Type                                 :  Low Noise Charge Sensitive Preamplifier
   Output                              :  100 mV for 5015MeV
Gain                                  :  600 mV/pC
Rise Time                          :  2 uS
Fall Time                           :  800 uS
Pulse Polarity                    : Positive
   Interconnecting cable length between preamplifier and amplifier - 3 meters
Amplifier
Input                                 :  0 to +500 mV
Output                               :  0 to +8 Volts
Shaping                             :  2 uS, Near Gaussian shape
Gain                                  :  Variable through 10 turn helipot
HV

Range                               :

 0 to +100 V
Ramp-up Time                  :

 1 min/50V
ADC  
ADC Type                           :  10 Bit Wilkinson Type
ADC Range                         :  8 Volts
No. of Channels                 :  1024Secs
Display & Storage System / Panel PC  

  Industrial Panel PC or Laptop with Windows XP (License version) operating system for display of MCA spectrum, data analysis
  and spectrum storage. PC will have RS232/RS485 or Ethernet port for data communication.
  12” LCD Monitor for display.
  Display Resolution At least 1024 x 760 pixels

ADC Range                         :  8 Volts
No. of Channels                 :  1024Secs
Alarms

 Warning Alarm Level & Final Alarm Levels settable in terms of Bq/m3. Relay outputs 2 changeover for remote monitoring.
 Remote acknowledgement and reset.
Flow Meter   

 Digital Flow meter for flow rate measurement.
 Range 0 to 100 LPM
 Others
Temp. Range                     :  0 to 55O C
 Air Sampling Unit  
 SS Air Sampling head capable of holding filter paper of 37 mm dia. Collection efficiency >95%.
 Flow range 10 to 100 LPM
 Filter Paper Millipore type. Wire mesh for supporting filter paper.
 Vacuum Pump - Oil less, Capacity 100 LPM with 12.7mm dia inlet and outlet ports
 Digital Flowmeter, range 0 to 100LPM for flow rate measurement.
 Bypass valve for bypassing excess flow.
 Suitable Trolley will be provided for entire system with grills for ventilation.
   

 

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