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4. THEORY OF OPERATION  page 31 

 

Model BM-286A 

4.2.5.  Discriminator Card, RCS-120: 

Refer to "RCS-120 Schematic Diagram" Drawing 8 and "RCS-120 Component Designator" 

Drawing 9 (Appendix F.). 

 

The ±15 volt power supply voltages are regulated to ±12 volts and +5 volts used on this card.  

The card is lined with test points for measurement of the discriminator levels. 

 

U7 generates the negative 10 volt reference used by the serial digital to analog voltage converters 

(U1,5,8,10).  The converters are selected by the computer through the CIF-553 via U3; a 

programmable gate array.  Serial data and clock are also generated by the CIF differential drivers 

and U4 receiver decodes this information.  Voltage outputs from the converters go to operational 

amplifiers and transistor drivers to each RCS-110 card by the 44 edge card connector. 

 

4.2.6.  Computer Interface Board, CIF-553: 

Refer to "CIF-553 Schematic Diagram" Drawing 17 and "CIF-553 Component Designator" 

Drawing 18 (Appendix F.). 

 

This board is located in the DOS machine.  TSA Systems manufactures the CIF-553 board for 

use in their PC based products.  The CIF-553 has the following characteristics: 

 

•  Twenty-one - 16 bit counters 

•  Three - 8 bit I/O ports 

•  Twenty-four -  differential line receivers 

•  Four - differential line transmitters 

•  Two - ribbon connectors (50 & 34 pin)  

    which interface with the backplane (RCS- 130) 

•  The counters are used for the radiation detectors, motor encoders, etc. 

•  The ports are used for system control and discriminator setting. 

•  Port "C" has 4 differential line drivers and line receivers. 

•  The Address of the card is 1000. 

 

Summary of Contents for BM-286A

Page 1: ...WASTE MONITOR MODEL BM 286A OPERATING AND SERVICE MANUAL Version 1 00z December 20 2004 ...

Page 2: ...VERVIEW 7 3 2 POWER UP AND SELF TESTS 8 3 3 NORMAL OPERATION 11 3 4 PROGRAMMING THE SYSTEM 13 3 5 DIAGNOSTICS AND UTILITIES 22 3 6 REPORTS 24 3 7 INITIAL INSTALLATION CHECKLIST 25 3 8 WASTE STREAM SET UP WORKSHEET 27 4 THEORY OF OPERATION 28 4 1 UNIT OPERATION 28 4 2 COMPONENTS 28 5 MAINTENANCE 33 5 1 OPERATOR MAINTENANCE 33 5 2 CALIBRATION 33 5 3 DISCRIMINATOR ADJUSTMENT 36 5 4 WEIGHT CALIBRATION...

Page 3: ... A WARRANTY 42 B GLOSSARY 43 C FORMULAS 45 C 1 ACTIVITY FROM COUNTS 45 C 2 EFFICIENCY 45 C 3 N SIGMA ALARM LEVEL 45 C 4 RELIABLE DETECTABLE ACTIVITY RDA FORMULA 46 C 5 SIGNAL TO BACKGROUND RATIO 46 C 6 VARIANCE 47 D CONFIGURATION TRACKING SHEET 48 E PARTS 49 E 1 RECOMMENDED SPARE PARTS 49 E 2 SPARE PARTS ORDERING INFORMATION 49 F DRAWINGS 50 ...

Page 4: ...e provided for spectral monitoring Operation of the instrument is controlled from a touch screen LCD monitor or optionally using an external computer keyboard All access is controlled by user assigned password protection A printer can be connected for report printing or the printing of container data labels The instrument performs a self test and acquires a new background count each time it is pow...

Page 5: ...ipes Total detector volume is 3 384 in3 55 liters Optional Detector One 3 x 3 NaI Tl Display Super VGA color flat panel monitor with touch screen Power Input 120V 60 Hz 3A Requirements 115 230 Vac 47 63 Hz 400 VA Time Scan 1 to 50 000 seconds user programmable Background 20 to 10 000 seconds user programmable Serviceability May be repaired to the board subassembly level in the field Dimensions Ove...

Page 6: ...pounds 2 3 to 455kg Environmental Temperature 32 to 100 F 0 to 40 C operating 0 to 120 F storage Humidity 0 to 95 Relative Humidity non condensing Accessories included with system VGA color monitor 101 key keyboard Components optional Printer NaI Tl detector and 1 024 channel MCA for spectral isotopic identification ...

Page 7: ...1 INTRODUCTION page 4 Model BM 286A ...

Page 8: ...special requirements 2 1 INSPECTION 2 1 1 Incoming Inspection Immediately inspect the instrument for mechanical damage scratches dents or other defects It should be examined for evidence of concealed as well as external damage 2 1 2 Damage Claims If the instrument is damaged in transit or fails to meet specifications upon receipt notify the carrier and TSA Systems immediately Shipping cartons pack...

Page 9: ...mber must be connected to the NT computer by removing the top and right side panels Mount the monitor with the screws provided on the right side and connect the cables marked 1 2 and 3 power VGA COM2 to the back of the Windows NT computer chassis The optional keyboard is stored next to the computer and can be connected for data entry The power cord located on the left side of the unit plugs into a...

Page 10: ...hecklist should be duplicated and filled in for each test source that will be used with the system A copy of the completed form should be kept in a convenient location as a reference for identifying future problems The Waste Stream Programming Worksheet contains entries for each of the operating parameters in the individual waste streams The instrument permits up to 20 pre programmed waste streams...

Page 11: ...dule off for a few seconds and then back on to re initiate the tests Once the computer has successfully completed its tests and the program is executing the instrument will display the normal background collection screen The detector windows should be gray and a pop up window displaying the message GETTING nn SECOND BACKGROUND will appear The chronograph will show the remaining time of the count A...

Page 12: ...password protected Print sample data Set up menu TARE scale Utilities Bkg Rec record background Set up waste streams Operator log on Operator log off Invokes the PCAP software optional The available functions in the access menu are defined as follows Sample Data Sample data prints out a sample of data to the printer This is useful to verify alignment when installing label stock The data included i...

Page 13: ...itial Set Up For initial setup use this information User name TIM Badge 11 Password OK Delete this record after you have entered your information User Log Off User log off is used to log the current user off the system to prevent unauthorized access when the machine is left unattended PCA II PCA II is optional Set Up Set Up allows the system s operating parameters to be examined or changed Utiliti...

Page 14: ...r the badge number press Enter enter the password press Enter NOTE To prevent unauthorized use of the system the operator must log off by pressing the log off button whenever the unit is left unattended After the initial background has been collected and an operator has logged onto the system the monitor is ready for operation Place the container to be scanned on the weight scale platform and clos...

Page 15: ...imum weight of the waste stream exceeded At this point the article may be removed or the operator may press OK as prompted by the monitor and the waste stream menu will reappear After a valid waste stream is entered the operator will be prompted for an Item I D a touch screen keyboard will appear Press Enter if no Item I D is required The monitor will then scan the item and show the time to comple...

Page 16: ...nformation until the door is opened When the door is opened the scan information is cleared The system is now ready for a new sample 3 4 PROGRAMMING THE SYSTEM Programming the system can only be done by a level 0 operator The general set up function sets the global system parameters which are detailed in the Set Up Menu section 3 4 1 Setting up waste streams involves setting the parameters for the...

Page 17: ...r Stream 0 OK The available menu parameters are defined as follows Background Time Background time in seconds Enter a value between 20 and 10 000 Background Method Two methods of background count are incorporated in the BM 286A They are selectable from the Set Up Menu The Rolling background method is the standard for TSA products For a count time of N seconds the count is updated every N 10 second...

Page 18: ... from any detector exceeds this value the unit will enter a FAULT mode Variance Time This menu parameter sets time per variance test in seconds Enter a value between 10 and 100 Refer to Variance section 3 5 1 for details Number of Trials This menu parameter sets the number of iterations for the variance test Enter a value between 3 and 10 Units of Weight This menu parameter selects either pounds o...

Page 19: ...luded in the reports and data sample information Enter any combination of eight alpha numeric characters User Stream This entry allows the system administrator to allow all operators access to any one or all 20 of the available waste streams If this entry is set to 0 the operator must select the appropriate waste stream for each item to be scanned If this entry is set to 1 19 the operator will onl...

Page 20: ...The operator may program up to 16 alpha numeric characters to provide a unique reference for each waste stream The existing I D will be displayed Count Time Scan time in seconds Enter a value between 1 and 50 000 or 0 for minimum count time If minimum count time is selected the system will automatically calculate the minimum time required to scan the item The following are assumed for automatic sc...

Page 21: ...larm type is selected If N Sigma alarm type is selected in conjunction with a 0 count time the count time will automatically be set to 30 seconds Count Display Selects the method used for displaying counts on the screen and in the reports The background counts will always be displayed in counts second The count display options only control the display after a scan The available options are 1 Total...

Page 22: ...if the alarm level is exceeded This may be up to 22 alpha numeric characters This message will be included on the data sample information and in the reports Clean Message This parameter entry is the message that will be displayed if the alarm level is not exceeded This may be up to 22 alpha numeric characters This message will be included on the data sample information and in the reports Maximum W...

Page 23: ...ciency 1 Manual entry method Enter an efficiency in percent Entering a 0 will disable the current waste I D 2 Automatic calculation The operator will be prompted for a count time in seconds and the calibration source activity in nanocuries Press BEGIN at which time a START button will appear Press the START button and the unit will then take an nn second background The operator will be prompted to...

Page 24: ...rm level in disintegrations per minute Enter a value between 10 000 and 1 000 000 000 This is the level above background that will generate a radiation alarm when the DPM alarm type is selected NOTE This value is used only when the Alarm Type is set to DPM 2 N Sigma Radiation alarm level in N Sigma N 1background background This is the count level that will generate a radiation alarm when N Sigma a...

Page 25: ...nformation are displayed for each detector The columns contain from left to right the mean counts the variance in counts S2 the variance to mean ratio R and the mean value of R Readings in the third column R should not exceed 0 49 TSA s normal acceptance criterion is that for the third pass no detector should show a mean value of R fourth column greater than 0 30 The results of each iteration are ...

Page 26: ...efficiencies are displayed but not stored Overall efficiency which is the sum of the efficiencies for the six plastic detectors is calculated with a test source in the center of the counting chamber 3 5 4 Operator Setup Operators can be deleted or added by name badge number password and level of accessibility Admin or User Be careful in selection of administrative access 3 5 5 Shut Down Pressing t...

Page 27: ...aste item id scan message activity nCi specific activity nCi kg kilogram weight net counts per second user logged on at that time The activity specific activity kilogram weight and net cps are stored in float format 3 6 1 Standard Report The Standard Report output is controlled from the Set Up Menu section 3 4 1 The following three options are offered None None disables report generation altogethe...

Page 28: ..._________nCi Serial No __________ Date of latest assay __________ No of Counts Right __________ Top __________ Left __________ Bottom _________ Back __________ Door __________ Total __________ Efficiency Right __________ Top __________ Left __________ Bottom _________ Back __________ Door __________ Total __________ Discriminator Settings LLD ___________ ULD __________ ...

Page 29: ...tandard Variance Time __________ seconds Number of Trials __________ Low Alarm Level __________ counts second High Alarm Level __________ counts second Minimum Weight __________ pounds Units of Weight Lbs Kg Reports All Alarms None User Stream __________ BM I D __________ Performed by ____________________________ Date _________ ...

Page 30: ..._ __ __ __ __ __ 22 characters max Maximum Weight ____________________ pounds Efficiency ____________________ Alarm Level ____________________ DPM N Sigma pCi g Waste Stream number _________________________ Waste I D __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ 16 characters max Count Time ____________________ seconds or 0 for minimum MCA Data Optional On Off Alarm Message __ __ __ __ __ __ __ ...

Page 31: ...ne every second via RS 232 The output consists of the door position and six detector counts The NT system continually monitors the serial data for fault conditions and displays any errors on the computer monitor If the system detects a fault condition it will not allow normal operation until the fault condition is corrected 4 2 COMPONENTS 4 2 1 Component Locations Refer to BM 286A Pictorial View D...

Page 32: ...ng program The program directory includes a support file with the discriminator settings WINDOWS NT 32 megabytes MB of RAM a hard disk drive and a 100 MB Zip drive The user setup and waste streams are stored on the hard disk The machine receives data from the DOS machine on COM1 scale data on COM3 and touch screen data on COM2 4 2 3 Backplane Card RCS 130 Refer to RCS 130 Schematic Diagram Drawing...

Page 33: ...elded MHV cables to the rack control module and then into the inputs on the backplane to the channel boards The analog signal is decoupled by C46 amplified by U8 and U7 and sent to the single channel analyzer The second amplifier SCA channels are not used in this application The SCA is made up of two voltage comparators U6 The amplified signal must fall between the LLD and ULD levels to be digitiz...

Page 34: ... Voltage outputs from the converters go to operational amplifiers and transistor drivers to each RCS 110 card by the 44 edge card connector 4 2 6 Computer Interface Board CIF 553 Refer to CIF 553 Schematic Diagram Drawing 17 and CIF 553 Component Designator Drawing 18 Appendix F This board is located in the DOS machine TSA Systems manufactures the CIF 553 board for use in their PC based products T...

Page 35: ... Component Designator Drawing 14 Appendix F The transmitter board is a quad differential line transmitter This board receives 5 volt logic inputs and converts them to differential outputs There is a 5 volt regulator on board This board has the input from the door position sensor 4 2 9 Low Voltage Power Supply Low voltage 5 and 12Vdc for the system are supplied by an open frame power supply 4 2 10 ...

Page 36: ...curate measurements There is a Calibration Checklist 5 5 at the end of this section Copies should be made and filled out each time the system is calibrated NOTE The high voltage affects the pulse amplitude so the high voltage must be tested before the RCS 110 amplifiers are calibrated This procedure should be performed only by qualified personnel Calibration equipment required DVM with 10MÛ input ...

Page 37: ...ould be turned maximum ccw to prevent inducing noise into the beta amplifier R8 R23 are amplifier offsets and should not require further adjustment The factory settings are 0 005 volts at TP13 and TP1 respectively 5 2 1 1 First Stage Pulse Amplitude The first stage pulse amplitude is set by adjusting the high voltage NOTE TP17 provides a divide by 100 test point for the high voltage This test poin...

Page 38: ...just R42 for 1 0 volts peak pulse amplitude Verify that TP17 is 14 volts Set oscilloscope 2 volts VOLTS DIV Move oscilloscope probe to TP13 Adjust R5 for 4 volts peak pulse amplitude NOTE Pulses of all amplitudes will be observed on the scope Refer to the typical pulse profile on Drawing 20 Appendix F However there should be a noticeable increase in the display intensity for those pulses having am...

Page 39: ...ector counts will appear with the previous upper and lower settings Using the up and down arrows the values for upper and lower can be changed but are not sent to the DOS machine until the send button is pressed Observe the counts in the detector boxes to insure you have not reached the lower level noise threshold The approximate energy level in keV can be obtained by multiplying the settings by 1...

Page 40: ...5 MAINTENANCE page 37 Model BM 286A 5 4 WEIGHT CALIBRATION The third party scale was calibrated at the factory and should not need calibration If a problem occurs contact TSA Systems for assistance ...

Page 41: ...Plastic Detectors Test Source Isotope __________ Activity __________ µCi Serial No ________ Date of latest assay __________ Peak Volts Right __________ Top __________ Left __________ Bottom _________ Back __________ Door __________ New Readings if adjusted Right __________ Top __________ Left __________ Bottom _________ Back __________ Door __________ Variance final readings only Number of trials ...

Page 42: ...es Menu From the Utilities Menu the following diagnostics may be selected 6 1 1 Scale Reset Scale Reset will power cycle the weight scale controller 6 1 2 Variance Variance tests the statistics of the detector counts versus a Gaussian distribution If periodic noise is being counted the results of the variance test will approach 1 0 Light leaks will result in a variance near 2 0 Refer to section 3 ...

Page 43: ...the system fails to operate properly note all anomalies and try to determine if or how they are related This will usually isolate the problem to some degree and reduce the time required to repair the system Always perform a thorough visual inspection of the suspect assemblies looking for loose connectors pinched and broken wires burned components and signs of overheating If nothing is found during...

Page 44: ...S 232 data to the NT machine can be examined by using Hyperterminal The settings should be COM1 9600 N 8 1 Use standard troubleshooting procedures on the NT machine 6 4 SIGNAL INTERFACE ASSEMBLY AND DETECTORS Channel boards RCS 110 may be substituted with system power on but the power must be turned off before changing the discriminator cards RCS 120 This will ensure that the discriminator setting...

Page 45: ...f the manufacturer s liability to TSA TSA reserves the right to modify the design of its product without incurring responsibility for modification of previously manufactured units Since installation conditions are beyond the company s control TSA does not assume any risks or liabilities associated with methods of installation or with installation results Every effort is made to keep the manuals up...

Page 46: ...ting Diode LLD The Lower Level Discriminator provides a threshold usually adjustable that determines the lowest signal level that will be accepted as a nuclear pulse by the system s electronics Some systems have both upper and lower level discriminators that can be used to set a discriminator window The discriminator window can be used to effectively reduce the background counts and increase syste...

Page 47: ...s filled the background is updated This results in a background update at background time 10 Initial background accumulation requires the full background time Standard Background Standard background requires the full background time for the initial background and updates ULD The Upper Level Discriminator provides a threshold usually adjustable that determines the highest signal level that will be ...

Page 48: ...s operate C 1 ACTIVITY FROM COUNTS Activity Activity in nCi Eff Decimal efficiency i e 10 0 1 Where N Net counts per second cps background cps C 2 EFFICIENCY N cps with source background cps Where activity test source activity in nCi C 3 N SIGMA ALARM LEVEL This formula calculates the minimum activity in disintegrations per minute that can be reliably detected under a given set of operational cond...

Page 49: ...n percent F false alarm level in cps FA false alarm sigma G intermediate variance RDA reliable detectable activity in DPM C 5 SIGNAL TO BACKGROUND RATIO The following formula is helpful is determining the optimum discriminator settings Always perform a variance test at the final setting of the lower level discriminator to ensure that system noise is not being introduced into the amplifier stage Q ...

Page 50: ...ks in the detectors and periodic noise in the electronics Periodic noise will result in a number of about 1 a light leak will usually result in a number larger than 2 The number displayed during a variance test is the absolute value of the average of a number of these tests with one test being performed every nn seconds The data is valid after three iterations of nn seconds The pass fail criteria ...

Page 51: ..._____________ ___________________________________________________________________________ INSTALLED BY ________________________________ DATE __________ MODIFICATION ____________________________________________________________ ___________________________________________________________________________ INSTALLED BY ________________________________ DATE __________ MODIFICATION _______________________...

Page 52: ...ct Number Product Serial Number TSA Stock number Part description from parts list provided with instrument When ordering programmed proms the software version is required This can be found on the prom label NOTE Model number suffixes are generally not included in the text of the manual however the suffixes in the PARTS LISTS must be included on orders for spare parts For Assistance Call TSA SYSTEM...

Page 53: ...S 110 Component Designator 7 RCS 120 Schematic Diagram 8 RCS 120 Component Designator 9 RCS 130 Schematic Diagram 10 RCS 130 Component Designator Front 11 RCS 130 Component Designator Rear 12 TRAN 1 Schematic Diagram 13 TRAN 1 Component Designator 14 RECV 1 Schematic Diagram 15 RECV 1 Component Designator 16 CIF 553 Schematic Diagram 7 CIF 553 Component Designator 18 Voltage Divider 4 7M Diagram 1...

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