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Ludlum 2241-2 RK Radiological Emergency

1. 777 Z O KE EE AR 1 J 6 2002 0 00 ASSY WW 10 780 2002 NUUS ASSY AGOE NIVW 2 W 9928 81 TI0 8Zv v 5 20 620 200 490 AN3 NDLO3NNUO 0 620 200 430945 3DNDdS 6 Title 1 5 VOLTAGE DIVIDER 14 FEB 96 Model VARIOUS Check __ ______ 5002 502 Approve 25 727557 Sheet 1 of 1 Series Sheet 17 002502R2P1 sch PO Box 810 501 Oak Street Sweetwater Texas 79556 U S A 1 800 622 0828 LUDLUM MEASUREMENTS INC rs ees Sed pusa Q I L Bino NoislAzs re uen vi 30 68 11 36108 20520058 100 80 01 77 70 Naba CE _____ 08 08 39 1704 31111 95 91 202 842 BLVMI33NS ONT HIT 2 Response Normalized to Cs 137 10 Energy Response for Ludlum Model 44 2 100 1000 10000 Gamma Energy keV
2. norsiagyy UH 594 2 j 33005 ENOJO 55050958 073G Adan ee Bao 7 LLL LL 280 805 BOY TO HILIMS 231111 86 42 98 EMO 84 NT SINUS UL 22 NOTLINNA 2 13004 Srj 80p gayaa 54135 Yn YR 831735 8313131Y8 330 LH we n 328383138 09078330 5 HILING in Ls Ts nome TEST LL 1 0171 7 8 Ege we x d 11 415 Nia 9 pro By 886 YOR 0508 w3 2912351260 PORT en SIR e Eu n 1514 INENG ts 550 800 21 PASTA INT 1 EO NTIN Ma kou mo 982 T ar t i ar ce 91 Mul MEE 1 s LE 124 DONY I In 3131338 mus 13 aks HAYOHINN 7 C22 89P5 sasi Ol Gy31 WATI Ha8O0HI ND D 992 090 ms m ym EN 2013313 dig ld ts cl ar wise toy inr NIYA gt 21 00 6108 KI INS NIYA KO e 3508 NIYH g ict E Mo Pane och aNG gt orm NE EA LEA PST
3. 9 z 6 ng v MN as S di q IN FN NEUTRON 3 neutral de 3 MS Aa 4 5 2 ELECTRON Mla There ate several types of ionizing negative sey radiation HA X rays and gamma rays like light represent energy transmitted in wave without the movement of material just as heat and light from a fire or the sun travel through space X rays and gamma rays are virtually identical except that X rays are generally produced artificially rather than coming from the atomic nucleus Unlike light X rays and gamma rays have great penetrating power and can pass through the human body Thick barriers of concrete lead or water are used as protection from them Alpha particles consist of two protons and two neutrons in the form of atomic nuclei They thus have a positive electrical charge and are emitted from naturally occurring heavy elements such as uranium and radium as well as from some man made elements Because of Page 6 4 June 2011 Model 2241 2RK Technical Manual Section 6 their relatively large size alpha particles collide readily with matter and lose their energy quickly They therefore have little penetrating power and can be stopped by the first layer of skin or a sheet of paper However if alpha sources are taken into the body for example by breathing or swallowing radioactive dust alpha par
4. NAN TA AA mis 902 99562 fi 133HS Saras anos HO e Y Vd 080761 00020 2 41405 07 00 59 alya 86 9 09720 2096 22 MNISHS MOVIE SEN WO 29 81 ASN HO 30 3S v8 ANY YOLSISIY H3AOO 9222 61 ASN AHN ALON NO 8009 10 3545 4AILOALOYA 9866 6 SL 41405 NOILOAS 105 YOLSISIY NO 0756 22 MNI4HS 99379 ISN 967 6004 Sant 1869 10 6099 41 10 33s 601 2002 91 X 1 8006 02 10 8277 946 Lz 34IM SSHSVNOIOO HOLSIS3M SHH 01 92 MNIMHHS 1 z vv04 0L LAS 90 X 26 0 002 62 6 0968 silva NOLLdINOS3Q AYOLSIH NOISIAZY 9 Gamma Energy Response for Ludlum Model 44 10 x LATES MW 5 2 5 o for Model 44 9 v iii THEE He SERERE peer cd jo 96 Aduana Id Average Beta Energy KeV ATEWASSY 2 PP W FULL v E M uwos 682 200 WAN SAG 49 200 355 7314 3801 9 X Ob b L AET AET AET Z
5. gamma Energy Response energy dependent Dead Time typically 80 microseconds Operating Voltage 900 volts Construction aluminum housing with beige powder coat paint Size 4 6 x 6 9 x 27 2 cm 1 8 x 2 7 x 10 7 in Weight 0 5 ke 1 Ib Indicated Use measuring low levels of mid to high energy gammas Scintillator 2 5 cm diameter x 2 5 cm thickness 1 x 1 in sodium iodide Nal T1 scintillator Sensitivity typically 175 cpm per R hr Cs Tube 3 8 cm 1 5 diameter magnetically shielded photomultiplier Operating Voltage typically 500 to 1200 volts Dynode String Resistance 100 megohm Construction aluminum housing with beige powder coat paint Size 5 1 18 5 cm 2 7 3 in Dia x L Weight 0 5 kg 1 Ib Page 3 4 June 2011 Model 2241 2RK Technical Manual Section 4 Section Identification of Controls and Functions Display The Model 2241 2 utilizes a four digit liquid crystal display LCD with a two digit overflow SCALER mode and moving decimal point The two smaller digits located in the lower right corner of the display indicate counter 08 50 pm v hr umR hr kC ms OFLOW ALERT ALARM BAT EL 7 OVERLOAD COUNTING 52 Ludlum Measurements Inc OVERFLOW when in the scaler counting mode equivalent to a six digit scaler or exponential power when in the parameter setup mode The upper right corner of the LCD displays units and multiplier s R
6. 10 0K 1 125mW 392 Ohm 1 1 8 W CONN 640456 8 100 EL BACKLIGHT LED MAIN DISPLAY LCD 8246 365 4E1 A W REV1 Page 10 4 Section 10 Part Number 09 6814 09 6813 09 6813 12 7751 12 7750 12 7748 12 7751 12 7750 12 7748 12 7751 13 8039 5408 259 04 5658 06 6358 06 6358 12 7839 12 7054 13 8039 07 6527 07 6383 June 2011 Model 2241 2 Switch Board Drawing 408 x 45 CAPACITORS INTEGRATED CIRCUITS SWITCHES RESISTORS MISCELLANEOUS Chassis Wiring Diagram Drawing 408 x 131 SWITCHES RESISTOR CONNECTORS Ludlum Measurements Inc Technical Manual Reference Description BOARD Completely Assembled Switch Board C1 C2 10V C3 C4 10uF 20V C5 47 10V C6 100uF 10V U1 MAX220EPE S1 350134GSK FUNCTION 16 POS S2 LEFT S3 UP 54 ENTER RI R2 22K P6 CONN 1 640456 3 MTA100 P10 CONN 208006 2 S1 30 1 GRAYHILL 53 54 7101 SYZ QE C amp K S5 30 1 GRAYHILL S6 PA 600 210 S7 MPS 103F S8 MTL 306D Toggle Switch R1 10 M 1 4W 5 CONN 1 640442 2 MTA100 J2 CONN 1 640442 3 MTA100 J3 CONN 640442 6 MTA100 J4 CONN 640442 2 MTA100 J5 CONN 1 640442 2 MTA100 Jo CONN 1 640442 3 MTA100 77 18 CONN 640442 8 MTA100 J9 Series C UG706 U Page 10 5 Section 10 Part Number 5408 052 04 5578 04 5592 04 5578 04 5576 06 6359 08 6721 08 6716 08 6716 08 6716 10 7070 13 8100 13 8451
7. Radioisotope source for medical therapy 2702 7 Ci 1 kg 2 2 Ib of 50 year old vitrified high 270 27 Ci level nuclear waste 1 luminous Exit sign 1970 27 027 1 kg 2 2 Ib of uranium 675 68 X 10 Ci 1 kg 2 2 Ib of uranium ore Canadian 15 675 68 X 10 Ci Page 6 2 June 2011 Model 2241 2RK Technical Manual 0 3 1 kg 2 2 Ib of uranium Australian 13 51 X 10 Ci Section 6 1 kg 2 2 Ib of granite 1 kg 2 2 Ib of low level radioactive waste 27 03 X 10 Ci 1 kg 2 2 Ib of coal ash 541 X 10 Ci 2 70 X 10 Ci NB Though the intrinsic radioactivity is the same the radiation dose received by someone handling a kilogram of high grade uranium ore will be much greater than for the same exposure to a kilogram of separated uranium since the ore contains a number of short lived decay products see section on Radioactive Decay Radioactive Decay Atoms in a radioactive substance decay in a random fashion but at a characteristic rate The length of time this takes the number of steps required and the kinds of radiation released at each step are well known URRNIUH 238 1238 RRDIORCTIUE DECAY type of nuclide radiation uranium 238 thorium 234 protactinium 234m uranium 234 thorium 230 2 9 radium 226 8 2 c 2 ccc 9 Q 6 O 0 0 O0 0 O 0 06 e 0 9 6 radon 222 polonium 218 lead 214 bismuth 214 polonium 214 lead 210 bismuth 210
8. can display in R hr Sv h cpm or cps Time Base can display in seconds or minutes Audio Divide 1 10 100 or 1000 events per click Response Time variable or fixed ratemeter response All stated times correspond to a range of 10 to 90 of the final reading Factory default is variable so that the instrument will automatically adjust the response time to the best setting for the current count rate Variable Response dependant on the number of counts present typically 4 to 25 seconds for FAST and 4 to 60 seconds for SLOW Fixed Response The parameter is adjustable from 1 25 seconds resulting in a FAST response from approximately 2 50 seconds The SLOW response is approximately 10 250 seconds For MDA type measurements the fixed response mode is recommended Ratemeter Alert Alarm set at any point corresponding to the pre selected ratemeter range Scaler Alarm adjustable from 1 to 999999 counts Scaler Count Time adjustable from 1 to 9999 seconds Indicated Use alpha beta gamma sutvey and frisking Detector pancake type halogen quenched Geiger Muller GM Window 1 7 0 3 mg cm mica Page 3 3 June 2011 Model 2241 2RK Technical Manual Section 3 Model 44 2 Detector Ludlum Measurements Inc Window Area Active is 15 cm and open is 12 Efficiency geometry typically 5 for 22 for Sr Y 19 for 32 for P and 15 for Sensitivity typically 3300 cpm mR hr
9. control inputs and display information The clock frequency is crystal controlled by Y221 and related components at 6 144 MHz The incorporates internal memory ROM storing the program information U1 resets the uP at power up to initiate the start of the program routine During the program loop the looks at all the input switches for initiation or status changes and responds accordingly U122 is a 256 x 8 bit EEPROM used to store the setup parameters The information is transferred serially from the uP The EEPROM is non volatile meaning it retains memory even after power is removed Audio Click per event divide by and alarm audio pulse frequency is generated by the uP and coupled to Q101 0101 then inverts the pulses and drives the bottom of T101 Bias voltage is provided by the volume control R002 to the top of T101 Page 7 2 June 2011 Model 2241 2 Refer to the Switch Board schematic for the following Refer to Display Board schematic for the following Ludlum Measurements Inc Technical Manual Section 7 57 FUNCTION S1 is a 16 position binary rotaty switch which selects the programmable parameters for the Model 2241 2 The switch selects the parameters using the hexadecimal numbering system via buss lines SW1 SW4 52 54 52 54 pushbutton switches that enter change the vatiables for each of the 16 parameters U1 U1 is a 5 V powered RS 232 driver receiver used to interface the Model 2
10. polonium 210 lead 206 Ludlum Measurements Inc Page 6 3 half life 447 billion years 241 days 1 17 minutes 245000 years 8000 years 1600 years 3 823 days 3 05 minutes 26 8 minutes 19 7 minutes 0 000164 seconds 22 3 years 5 01 days 138 4 days stable The half life is the time taken for half of the atoms of a radioactive substance to decay Half lives can range from less than a millionth of a second to milions of years depending upon the element concerned After one half life the level of radioactivity of a substance is halved after two half lives it is reduced to one quarter after three halflives to one eighth and so on Al uranium atoms are mildly radioactive The following figure for uranium 238 shows the series of different radioisotopes it becomes as it decays the type of radiation given off at each step and the half life of each step on the way to stable non radioactive lead 206 June 2011 Model 2241 2RK Technical Manual Ludlum Measurements Inc Section 6 The shorter lived each kind of radioisotope the more radiation it emits per unit mass Much of the natural radioactivity in rocks and soil comes from this decay chain lonizing Radiation Here we are concerned mainly with ionizing radiation from the atomic nucleus It occurs in two forms rays and particles at the high frequency end of the enerey spectrum ANATOM P PROTON positiv 10 4 I
11. the variable mode The fast position varies the TC from 4 25 seconds and the slow position varies from 4 60 seconds Fixed Response The Fast response position 15 programmable from 2 50 seconds and the slow response is 5 times the fast TC For MDA type measurements the fixed response time mode is recommended POSITION 7 RATEMETER ALARM ALERT allows changing the ratemeter alarm for the current detector setup The units of this alarm are the same as the units for the ratemeter display The fifth push of the left button allows the decimal point to be moved ratemeter alarm adjusts from 1 to 999 R hr or Sv h or 1 to 999 kcpm or 1 to 100 kcps The units of the alarm determined by the units for the ratemeter POSITION 8 SCALER ALARM COUNT TIME sets the scaler alarm variable from 1 999999 corresponding to the accumulated scaler count After the scaler alarm variable is entered the scaler count time is prompted The scaler count time 15 adjustable from 1 9999 seconds POSITION 9 NOT USED Ludlum Measurements Inc Page 8 5 June 2011 Model 2241 2RK Technical Manual Section 8 Ludlum Measurements Inc POSITION A NOT USED POSITION B LCD Backlight ON TIME is the amount of time that the LCD backlight will stay on after pressing the front panel switch labeled LIGHT This value is stored in EEPROM Available values are 5 seconds 30 seconds 60 90 seconds 180 240 seconds POSITION C SET MINIMUM DISPLAY
12. time base to units time base The CC must be set to 1 to readout in cps counts per second or cpm counts per minute CC CONVERSION TABLE Conversion Rate Multiply by to get CC cps uR hr 3 6 x 10 cps mR hr 3 6 x 10 cps R hr 3 6 x 10 cpm uR hr 6 0 x 10 cpm mR hr 6 0 x 10 cpm R hr 6 0 x 10 cps uSv h 3 6 x 107 cps mSv h 3 6 x 10 cps Sv h 3 6 x 10 cpm uSv h 6 0 x 10 cpm mSv h 6 0 x 10 cpm Sv h 0 6 Example The Model 44 9 GM detector produces approximately 3300 cpm mR hr for 6 0 x 10 x 3300 198 x 10 for e POSITION 3 DISPLAY UNITS selects the display units for the associated detector setup number The Model 2241 2 and detector may be calibrated in either exposure rate R hr Sv h by entering the appropriate Calibration Constant position 2 and Dead Time correction Ludlum Measurements Inc Page 8 3 June 2011 Model 2241 2RK Technical Manual Section 8 position 1 The Model 2241 2 will automatically convert to the correct reading when switching between R and Sv The time base for count is set independently in position 4 The display units may be set to R hr Roentgens per hour Sv h Sieverts per hour C time base Counts pet time The display is auto ranging with the appropriate multiplier symbol appearing in front of or indicating the range uR hr mR hr R hr uSv h mSv h Sv h C s kC s C m kC m POSITION 4 TIME BASE CPS O
13. 01 12 05 Design RSS 01 12 05 MAIN BOARD 2241 OS Board 5408 223 S Re 10 Series Sheet mw TAEI 12081224 85408223 640456 2 i i i i 2 oes DTE TNR er NOLIRGTWO 1371111 mam 0919091 8171 02 343 ee II 8015 1316 2 NAIS LINSYH dHo9 D31sYd 4402 495 ri duO2 7 805 B JE USE 9 5093 26022 02540 NOfivear iva 731111 B6 NWn 21 39V 54 H31VHI33MS SINSHBUNSYEH LIN HAY O NSYH 475 0 21594 un 5 0 31574 dW09 O TINO AMIS 3NI 400 6 423 5 81 46 91 064 5 SR Ser 3385 Sov 831136 2 1 22 dou 554 8851 89180958 891 8095 W uvoS 25 5 723 AH NOllYUBI TYO 3ILIL 86 30v _ 81 SINSUSUDSY34 gl gt S sc ERR E trean Ouvos SIPOVS 9050
14. 2241 2RK Technical Manual Section 4 Ludlum Measurements Inc mode when the six digit display four digits display and two overflow digits in right corner reaches 999999 and starts to roll over again OVERLOAD This indicates that the detector is being exposed to radiation intensities greater than the detector maximum operating limit For alpha and or beta type scintillation detectors an OVERLOAD may indicate that the detector face has been punctured allowing external light to saturate the photomultiplier tube inside the detector The overload alarm point is set by adjusting the OVL control located underneath the calibration cover Note Ovetload is set for detector Model 44 9 only Low battery icon This indicates that the batteries have decreased to the minimum operating voltage of 2 2 0 1 Instrument will continue to operate for approximately 24 hours thereafter COUNTING This indicates that the scaler COUNT switch has been depressed and that the scaler is accumulating counts for the pre determined count time Front Panel Controls DET1 DET2 Detector Select Switch a protected locking toggle switch used to select between DET1 and DET2 parameters The switch can be pulled up and then over to the desired selection OFF RATEMETER SCALER Switch a three position rotary switch that applies power to the instrument and selects RATEMETER ot SCALER counting mode AUD ON OFF Switch clicks per event audio may b
15. GM type detectors It is designed fot the rugged use of first responders in the measuring of ionizing radiation A rugged waterproof airtight carrying case with foam insert check source with holder and detector cable are provided T he Model 2241 2RK is a first responder kit that includes a portable The Instrument Data is presented on a four digit six digits the Scaler mode Liquid Crystal Display LCD with moving decimal point A three position switch labeled OFF RATEMETER SCALER selects the desired operating mode for the instrument A locking toggle switch labeled DET 1 and DET Z allows for quick change of operating parameters when changing out detectors Programmable display units RATEMETER mode only can be represented in R hr Sv h cpm or cps with multipliers of micro u or milli m for R hr and Sv h and kilo for cpm or cps The display units ate auto ranging enabling the readout to display a broad range of radiation levels The display also offers lower limit capability For example the display can be set to show only values that ate greater than or equal to 1 uR hr This instrument incorporates independent adjustable alarms for RATEMETER and SCALER operating modes The RATEMETER mode has two alarm indicators The first level alarm is indicated by display of the word ALERT on the LCD The second level alatm is indicated by display of the word ALARM by the emitting of a continuous audible to
16. Measurements Inc Technical Manual Reference C241 C242 C243 C251 Q101 Q141 Q211 Q212 Q241 1 001 011 021 111 121 122 131 231 a Cc G CR021 CR031 CR041 CR044 CR231 CR241 CR242 R002 R027 R001 R011 R012 R013 R014 R015 R021 R022 Description 1uF 35V 68uF 10V 50V 68uF 10V 2N7002L MMBT3904LT1 2N7002L MMBT4403LT1 MJD210 RL MAX810LEUR CD74HC4538M TLC3721D CA3096M 16 GND N87C51FC LM285MX 2 5 24 0258 5 LM358D LT1073CS8 5 SOCKET 44P MMBD7000LT1 GI250 2 GI250 2 CXSH 4 EB33 MMBD914LT1 CXSH 4 EB33 10K 3269X1 103 1M 3269X1 105 HV LIMIT 100K 1 4W 1 10K 1 4 W 1 1K 1 4W 1 10K 1 4W 190 100K 1 4W 1 1M 1 4W 5 392K 1 8W 1 Page 10 2 Section 10 Part Number 04 5656 04 5654 04 5663 04 5654 05 5840 05 5841 05 5840 05 5842 05 5843 06 6424 06 6297 06 6290 06 6288 06 6303 06 6291 06 6299 06 6312 05 5852 06 6613 07 6355 07 6266 07 6266 07 6358 07 6353 07 6358 09 6921 09 6906 12 7834 12 7839 12 7832 12 7839 12 7834 10 7028 12 7841 June 2011 Model 2241 2RK Technical Manual Section 10 Reference Description Part Number R023 10K 1 4W 1 12 7839 R024 R025 4 75K 1 4W 1 12 7858 R026 8 25K 1 8W 1 12 7838 R031 1 4W 5 10 7030 R032 1M 1 4W 5 10 7028 R033 R034 1G FHV 1 2 12 7686 R111 R113 22 1K 1 4W 1 12 7843 R121 100 Ohm 1 4W 1 12 7840 R122 6 81
17. all such regulations and acknowledges that it has the responsibility to obtain licenses to export re export or import Software This License shall be governed by and construed in accordance with the laws of the State of Texas United States of America as if performed wholly within the state and without giving effect to the principles of conflict of law If any portion hereof is found to be void or unenforceable the remaining provisions of this License shall remain in full force and effect This License constitutes the entire License between the parties with respect to the use of the Software Restricted Rights Ludlum s software is provided to non DOD agencies with RESTRICTED RIGHTS and its supporting documentation is provided with LIMITED RIGHTS Use duplication or disclosure by the Government is subject to the restrictions as set forth in subparagraph C of the Commercial Computer Software Restricted Rights clause at FAR 52 227 19 In the event the sale is to a DOD agency the government s rights in software supporting documentation and technical data are governed by the restrictions in the Technical Data Commercial Items clause at DFARS 252 227 7015 and DFARS 227 7202 Manufacturer is Ludlum Measurements Inc 501 Oak Street Sweetwater Texas 79556 Ludlum Measurements Inc Page 8 23 June 2011 Model 2241 2RK Technical Manual Section 9 Section Ludlum Measurements Inc Recycling products it produces for the purpose of pr
18. as defined by IEC 664 Occurs when conductive pollution or dry nonconductive pollution becomes conductive due to condensation This is typical of industrial or construction sites Detector Connector Caution The detector operating voltage HV is supplied to the detector by way of the input connector A mild electric shock may occur if contact is made with the center pin of the input connector Switch the Model 2241 2 to the OFF position before connecting or disconnecting the cable or detector Warning Markings and Symbols Caution The operator or responsible body is cautioned that the protection provided by the equipment may be impaired if the equipment is used in a manner not specified by Ludlum Measurements Inc Ludlum Measurements Inc Page 5 1 June 2011 Model 2241 2RK Technical Manual Section 5 Dx Ludlum Measurements Inc The Model 2241 2 Survey Meter is marked with the following symbols CAUTION RISK OF ELECTRIC SHOCK per ISO 3864 No B 3 6 designates a terminal connector that allows connection to a voltage exceeding 1 kV Contact with the subject connector while the instrument is on or shortly after turning off may result in electric shock This symbol appears on the front panel CAUTION per ISO 3864 No B 3 1 designates hazardous live voltage and risk of electric shock During normal use internal components are hazardous live This instrument must be isolated or disconnected from the h
19. by two standard D cell batteries The unit body is made of cast and drawn aluminum with beige powder coating which aids in the decontamination of surfaces The Detectors The Response Kit s GM Geiger Mueller Pancake Detector Model 44 9 will detect alpha beta and gamma radiation Its size and shape provide easy handling for sutveying or personnel monitoring The detector is energy dependant over responding by a factor of 6 to gamma radiation in the 60 keV 100 keV range when normalized to The response of this detector is nominally linear within 10 from 1 mR hr to 300 mR hr The Model 44 9 operates at 900 volts The recommended instrument input sensitivity set at calibration is approximately 30 10 mV to prevent the detector from double pulsing The thin mica window in this detector is protected by a 79 open stainless steel screen The GM tube can be easily removed for replacement if necessary The GM tube face may rupture above 8000 feet altitude pressure Consequently tube failure is likely if transported above this altitude in an aircraft not pressurized Page 1 2 June 2011 Model 2241 2RK Technical Manual Section 1 Ludlum Measurements Inc The Response Kit s sodium iodide Nal gamma scintillator Model 44 2 is used for the detection of low level gamma radiation in the range of 60 keV 1 25 MeV The detector is energy dependant over responding by a factor of 10 or greater in the 100 keV ran
20. computer s nine pin RS 232 port RS 232 CONNECTOR PIN OUT 7 FUNCTION NC No Connection DATA OUT DATA IN NC NC NC HANDSHAKING IN HANDSHAKING OUT NC 9 DN Ludlum Measurements Inc offers PC compatible software program that incorporates the read write commands necessary to communicate between the PC and the Model 2241 2 The program also incorporates an algorithm to calculate the detector Calibration Constant and Dead Time Constant The softwate is offered in a DOS version part number 1370 025 or a WINDOWS version part number 1370 024 Read the Software License Agreement at the end of this section before installing any LMI software Calibration The Model 2241 2 calibration routine consists of entering detector parameters into memory by way of the switch board and adjusting the CAL controls HV DISC and OVI for the specific detector operating requirements The first subsection of calibration will give a general overview of detector setup including the determination of various detector operating voltages HV and the adjustment of counter input sensitivity DISC Page 8 7 June 2011 Model 2241 2RK Technical Manual Section 8 The next subsection deals with pulse generator counts per minute calibration The counts per minute parameter setup is used in the initial instrument checkout procedure and the variables saved under detector setup number 1 when shi
21. expect approximately eight additional deaths 0 08 X 10 000 X 1 rem So instead of the 2000 people expected to die from cancer naturally you would now have 2008 This small increase in the expected number of deaths would not be seen in this group due to natural fluctuations in the rate of cancer What needs to be remembered is that it is not known that eight people will die but that there is a risk of eight additional deaths in a group of 10 000 people if they would all receive 1 rem instantaneously If they would receive the 1 rem over a long period of time such as a yeat the risk would be less than half of this lt 4 expected fatal cancers Risks can be looked at in many ways Here a few ways to help visualize risk One way often used is to look at the number of days lost out of a population due to early death from separate causes then dividing those days lost between the population to get an average life expectancy lost due to those causes following is a table of life expectancy lost for several causes Health Risk Est life expectancy lost Smoking 20 cigarettes a day 6 years Overweight 15 2 yeats Alcohol US Avg 1 yeat Accidents 207 days Natural Hazards 7 days Occupational dose 300 mrem yr 15 days Occupational dose 1 rem yr 51 days Page 6 9 June 2011 Model 2241 2RK Technical Manual Section 6 Ludlum Measurements Inc You can also use the same approach to looking at risks on the
22. job Industry Type Est life expectancy lost All Industries 60 days Agriculture 320 days Construction 227 days Mining and quarrying 167 days Manufacturing 40 days Occupational dose 300 mrem yr 15 days Occupational dose 1 rem yr 51 days These are estimates taken from the NRC Draft guide DG 8012 and were adapted from B L Cohen and LS Lee Catalogue of Risks Extended and Updates Health Physics Vol 61 September 1991 Another way of looking at risk is to look at the relative risk of one in a million chances of dying of activities common to out society Smoking 1 4 cigarettes lung cancer Eating 40 tablespoons of peanut butter Spending 2 days in New York City air pollution Driving 40 miles in a car accident Flying 2500 miles in a jet accident Canoeing for 6 minutes Receiving 10 mrem of radiation cancer Adapted from DOE Radiation Worker Training based on work by B L Cohen Sc D Background Radiation Naturally occurring background radiation is the main source of exposure for most people Levels typically range from about 150 350 mrem per year but can be more than 5rem yr The highest known level of background radiation affecting a substantial population is in Kerala and Madras States in India where some 140 000 people receive doses that average over 1 5 rem year from gamma radiation in addition to a similar dose from radon Comparable levels occur in Brazil and Sudan with average exposures up to about
23. or dose received by a person is measured in terms of the energy absorbed in the body tissue and is expressed in RAD One rad is 0 01 joules deposited per kilogram of mass Equal exposure to different types of radiation expressed as RAD do not however necessarily produce equal biological effects One rad of alpha radiation for example will have a greater effect than one rad of beta radiation When we talk about radiation effects we therefore express the radiation as effective dose in a unit called the REM Roentgen Equivalent Man Regardless of the type of radiation one rem of radiation produces the same biological effect 100 rem 1 Sv Smaller quantities are expressed in mrem one thousandth or millionth of a rem We will use the most common unit rem here What Are The Health Risks From lonizing Radiation It has been known for many years that large doses of ionizing radiation very much larger than background levels can cause a measurable increase in cancers and leukemias cancer of the blood after some years delay It must also be assumed because of experiments on plants and animals that ionizing radiation can also cause genetic mutations that affect future generations although there has been no evidence of radiation induced mutation in humans At very high levels radiation can cause sickness and death within weeks of exposure see table on next page But what ate the chances of developing cancer f
24. sets the ratemeter minimum displayable reading Depressing the RESET button displays the minimum ratemeter units The readout will auto range up to the maximum displayable but will display zero for ratemeter readings below the user programmed minimum vatiable Minimum displayable values 00 0 u 000 u 0 00 m 00 0 m 000 m 0 00 00 0 000 R hr 000 000 00 0 m 000 m 0 00 00 0 000 Sv h 0 00 00 0 000 0 00 k 00 0 k 000 kcpm or cps POSITION D RS 232 DATA DUMP MODE allows the RS 232 port to dump ratemeter data every two seconds The Model 2241 2 is fully functional during RS 232 data dump with the exception of the audio function The LCD will alternate between display of the ratemeter and the word dUP representing dump POSITION E RS 232 DETECTOR PARAMETERS SETUP MODE allows the RS 232 port to accept send a string of parameters corresponding to the current detector setup values POSITION F BAUD RATE configures the RS 232 port for the following baud 150 300 600 1200 2400 4800 9600 and 19200 The data is eight data bits one stop bit with no parity bit This value is stored in EEPROM The baud rate can only be programmed through the switch board Page 8 6 June 2011 Model 2241 2RK Technical Manual Section 8 Ludlum Measurements Inc RS 232 PORT CONNECTOR This nine pin D type connector is designed as a DCE port A straight wire cable extension cable connects the Model 2241 2 to a
25. 08 6517 08 6511 08 6517 08 6501 08 6699 08 6777 08 6698 10 7031 13 8407 13 8138 13 8171 13 8178 13 8407 13 8138 13 8184 13 7751 June 2011 Model 2241 2RK Technical Manual AUDIO BATTERY MISCELLANEOUS Ludlum Measurements Inc Reference j10 P10 051 1 2 Description JACK 09 9011 1 4193 Handle Pin UNIMORPH Duracell Battery Model 2241 Switch Board Add On Model 2240 Digital Bezel Assembly Bezel Back Bezel Back Gasket Portable Battery Contact Set Model 2241 2 Main Harness Portable Harness Can Wires Switch Board Harness Model 2241 Can Assy Assembled Battery Lid Casting Front Panel Lexan Battery Lid Lexan Label Model 3 Cal Cover Model 2242 Rolled Handle Assy Clip Probe with Screws Can Gasket Portable Knob Portable Battery Gasket Portable Calibration Covet with Screws Cable C 0 99 m 39 in only SOURCE 37 kBq 1 Check Source SOURCE HOLDER CARRYING CASE Page 10 6 Section 10 Part Number 18 9080 7408 055 21 9251 21 9313 4408 053 4408 020 7408 025 7408 026 2001 042 8408 151 8363 462 8408 027 4408 081 2363 191 7408 181 7408 208 7408 209 2310602 4408 178 7010 008 01 22 9773 08 6613 7363 183 9363 200 40 1004 01 5196 4062 166 2311063 June 2011 Model 2241 2 Model 44 9 Alpha Beta Gamma Detector PANCAKE Drawing 2 x 206 Model 44 2 Gam
26. 1 2 reads 800 cpm 10 on the ratemeter setting Adjust the pulser output to 200 cpm and confirm that the Model 2241 2 reads 200 cpm 10 on the ratemeter setting Adjust the pulser output to 800 cpm take a one minute count and confirm that the digital scaler readout displays 800 cpm 2 n Adjust the pulser output to 200 cpm take a one minute count and confirm that the digital scaler readout displays 200 cpm 2 Confirm that the 20 and 80 readings for the upper decades are within the pulser input by decading the pulser count output Confirm that the scaler readout is within 2 of the pulser input rate Ensure that the ALERT and ALARMs function by inputting the preset alarm levels as to initiate the alert and alatm conditions R hr CALIBRATION The following calibration procedure assumes that detector Calibration Constant CC and Dead Time Constant D TC are already known If these constants must be determined reference the following subsection Determining CC and DTC Switch the toggle switch to DET2 Detector setup number 1 is usually teserved for the Counts minute parameter calibration Rotate the FUNCTION switch counterclockwise to position 1 and enter the detector Dead Time in us Rotate to position 2 and enter the Calibration Constant Enter the desired parameters for positions 3 Switch to position 0 for normal operation Expose the detector to calibrated radiation fields extending from the lowet
27. 209 008 VSN 95564 BUKAL 8 paS 04 018 Od INI SLNAWAUNSYAM ANG SIE HE Qs I 6201 31 2 4 ys gone Pl 5 S1JY3AO mu ON LNNO 9 Wavy Way 240 DE P 36 gt gt 2 11 O Q 259R2X1 PCB 5 H H t Title LED BACKLITE DISPLAY BOARD Modek M2241 Board 5408 259 Series Sheet SCALE 1 00 408 260 24 2007 Dra Design 151516 40825962 1 25 07 RSS 23 07 Approve K8 2442 10 2m Pi Ba ons sanag 15004 3218 208 8085 41 024 wo AAT an a 88 29012 80 INI SIN3U3H0SY3 umm CBAYHSCNYH 514 3431934 I133VHSQNYH 104100 512 Blvd dnye ece ss BIEHN 40135 80123131 4350 LON FHIL 18002 Wey 87425 1 or 35Y83J11 Le 88 15 us 1331 25 ans Tas di ts 94 10451 S18 74 21 94 01 BARI B 39 ssa 1 33 dnis mang 8 54 5 5 5 94 NS LP t 25 284 M S
28. 2241 2RK Technical Manual Section 6 Ludlum Measurements Inc The Unstable Atom Radiation comes from atoms the basic building blocks of matter Most atoms ate stable a C atom for example remains a C atom forever and an atom remains an atom forever but certain atoms eventually disintegrate into a totally new atom atoms are said to be unstable radioactive An unstable atom has excess internal energy with the result that the nucleus can undergo a spontaneous change towards a more stable form This 15 called radioactive decay When an atom of a radioisotope decays it gives off some of its excess energy as radiation in the form of gamma rays or fast moving sub atomic particles One can describe the emissions as gamma beta and alpha radiation Apart from the normal measures of mass and volume the amount of radioactive material is given in curie Ci a measure which enables us to compare the typical radioactivity of some natural and other materials Radioactivity of some natural and other materials 1 adult human 2 7 X 10 Ci kg 1 89 X 10 Ci 1 kg 2 2 Ib of coffee 2 70 X 10 Ci 1kg 2 2 Ib of super phosphate fertilizer 1 35 X 10 Ci The air in a 100 1076 f Australian JB bore radon 812X 10 NE 2 2 The air in many 100 1076 ft European 8 12 X 107 Ci homes radon 1 household smoke detector with 812 X 107 Ci americium Radioisotope for medical diagnosis 1 89 X 10 Ci
29. 241 2 to a computer LCD Drive U1 and U2 are serial input 32 bit LCD drivers The data is loaded serially into the 32 bit shift registers internal via the IN input The LOAD input instructs the shift register to receive data while the CLOCK input shifts the data through the 32 bit registers After all the data 15 loaded the LOAD line is pulsed by the uP instructing the registers to transfer the data to the LCD drivers The backplane BP signal from 02 provides the reference signal approximately 125 Hz at 5 to the LCD DSP1 BP connection When a segment is illuminated the signal to that segment will be out of phase with the BP signal If the segment is OFF the signal will be in phase with the BP signal Backlight Drive Depressing the LIGHT button instructs the uP to set the BACKLIGHT line pin 31 on low for the predetermined backlight ON time Refer to main board schematic for details A low condition on pin 31 causes 0212 to conduct sending 3 V to P8 3 on Display board With 3 at P8 3 refer to display board schematic backlight oscillator 0011 011 and related components starts to oscillate producing 2 5 kHz sine wave signal The signal is amplified by 011 to 150 volts peak to peak to drive the LCD backlight Page 7 3 June 2011 Model 2241 2RK Technical Manual Section 8 Section Ludlum Measurements Inc Instrument Setup amp Calibration Factory Settings If special calibrati
30. 2RK Technical Manual Section 6 Ludlum Measurements Inc 2 rem yr averaged over 5 years is the limit for radiological personnel such as employees in the nuclear industry uranium or mineral sands miners and hospital workers who are all closely monitored 1 rem yr is the maximum actual dose rate received by any Australian uranium miner 300 500 mrem yr is the typical dose rate above background received by uranium minets in Australia and Canada 300 mrem yr approx is the typical background radiation from natural sources in North America including an average of almost 200 mrem yr from tadon in ait 200 mrem yr approx is the typical background radiation from natural sources including an average of 70 mrem yr from radon in air This is close to the minimum dose received by all humans anywhere on Earth 30 60 mrem yr is a typical range of dose rates from artificial sources of radiation mostly medical 5 mrem yr a very small fraction of natural background radiation is the design target for maximum radiation at the perimeter fence of a nuclear electricity generating station In practice the actual dose is less What is the risk estimate According to the Biological Effects of Ionizing Radiation Committee V V the risk of cancer death is 0 08 per rem for doses received rapidly acute and might be 2 4 times 0 04 per rem less than that for doses received over a long period of time chronic These risk estima
31. 4 tem yt to many people Several places are known in lran India and Europe where natural background radiation gives an annual dose of more than 5 rem and up to 26 rem at Ramsar in Iran Lifetime doses from natural radiation range Page 6 10 June 2011 Model 2241 2RK Technical Manual Section 6 up to a couple thousand rem However there is no evidence of increased cancets or other health problems arising from these high natural levels Manmade Radiation Ionizing radiation is also generated in a range of medical commercial and industrial activities The most familiar and in national terms the largest of these sources of exposure is medical X rays Natural radiation contributes about 88 of the annual dose to the population and medical procedures most of the remaining 12 Natural and attificial radiations are not different in kind effect Protection from Radiation Radiation is very easily detected There is a range of simple sensitive instruments capable of detecting minute amounts of radiation from natural and man made sources There are three ways in which people are protected from identified radiation sources 1 Limiting time For people who are exposed to radiation in addition to natural background radiation through their work the dose is reduced and the risk of illness essentially eliminated by limiting exposure time Proper job planning 15 essential in achieving lowest exposure time Always plan for the unexpe
32. E EVEN IF LUDLUM OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES In no event shall Ludlum s or its suppliers liability to Customer whether in contract tort including negligence or otherwise exceed the price paid by Customer The foregoing limitations shall apply even if the above stated warranty fails of its essential purpose SOME STATES DO NOT ALLOW LIMITATION OR EXCLUSION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES The above warranty DOES NOT apply to any beta software any software made available for testing or demonstration purposes any temporary software modules or any software for which Ludlum does not receive a license fee such software products are provided AS IS without any warranty whatsoever This License is effective until terminated Customer may terminate this License at any time by destroying all copies of Software including any documentation This License will terminate immediately without notice from Ludlum if Customer fails to comply with any provision of this License Upon termination Customer must destroy all copies of Software Software including technical data is subject to U S export control laws including the U S Export Administration Act and its associated regulations and may be subject to export or import regulations in other countries Customer agrees to comply strictly with Ludlum Measurements Inc Page 8 22 June 2011 Model 2241 2RK Technical Manual Section 8
33. K 1 4W 1 12 7857 R131 1M 1 4W 1 12 7844 R132 511K 1 8W 1 12 7896 R133 750K 1 4W 1 12 7882 R134 1M 1 4W 1 12 7844 R135 82 5K 1 8W 1 12 7849 R136 10K 1 4W 1 12 7839 R141 22 1K 1 4W 1 12 7843 R211 2 21K 1 4W 1 12 7835 R231 100Ohm 1 4W 1 12 7840 R241 2 21K 1 4W 1 12 7835 R242 200Ohm 1 8W 1 12 7846 CRYSTALS Y221 6 144 MHZ 2 GND 3 GND 01 5262 INDUCTOR L231 100uH CTX100 2 21 9740 TRANSFORMERS T101 4275 083 AUDIO 4275 083 T141 18050 40 0902 MISCELLANEOUS P1 1 640456 2 MTA100x12 13 8061 P2 1 640456 3 100 13 13 8100 P3 640456 6 100 6 13 8095 p4 640456 2 MTA100x2 13 8073 5 1 640456 2 MTA100x12 13 8061 CLVRLFE 18 8771 Calibration Board Drawing 408 x 127 BOARD Completely Assembled Calibration Board 5408 148 POTENTIOMETERS R110 1M HV2 SET 09 6814 R111 1M HV1 SET 09 6814 Ludlum Measurements Inc Page 10 3 June 2011 Model 2241 2 RESISTORS CONNECTOR Display Boa rd Drawing 408 x 259 CAPACITORS INTEGRATED CIRCUITS RESISTORS MISCI Ludlum Measurements Inc ELLANEOUS Technical Manual Reference R112 R113 R114 R115 R116 R118 R119 R120 R121 R122 P7 BOARD C1 U1 U2 R001 R004 R005 J1 DS1 DSP1 Description 1M OVERLOAD 100K DISC 2 100K DISC 1 1M 1 3W 1K 1 3W 10K 1 3W 1M 1 3W 1K 1 3W 10K 1 3W 1M 1 3W CONN 640456 8 MTA100 Completely Assembled Display Board 27pF 100V AY0438 I L AY0438 I L
34. LUDLUM MODEL 2241 2RK RESPONSE KIT June 2011 Serial Number 237627 and Succeeding Serial Numbers LUDLUM MODEL 2241 2RK RESPONSE KIT June 2011 Serial Number 237627 and Succeeding Serial Numbers LUDLUM MEASUREMENTS INC 501 OAK STREET PO BOX 810 SWEETWATER TEXAS 79556 325 235 5494 FAX 325 235 4672 ALTERATIONS ADDED DO NOT DISCARD SYMBOL 02 197041CLW 8 10 06 CMC 2 umR hr z kC ms OFLOW ALERT ALARM Rf OVERLOAD counting 88 MODEL 2241 2 SURVEY METER LUDLUM MEASUREMENTS INC SWEETWATER TEXAS DATE CHECKED CMC 8 10 06 bw 0 4 TITLE MODEL 2241 2 LUDLUM masus ae SHEET 408 75 Table of Contents Introduction 7 Getting Started 2 Unpacking and Repacking 2 1 Battery Installation 2 1 Operational Check 2 2 Survey Techniques 2 4 Specifications 3 Identification of Controls and Functions 4 Display 4 1 Display Status Definitions 4 1 Front Panel Controls 4 2 Front Panel Calibration Controls 4 3 Main Board Controls 4 4 Switch Board Controls 4 5 Safety amp Maintenance Considerations 5 Environmental Conditions for Normal Use 5 1 Detector Connector 5 1 Warning Markings and Symbols 5 1 Maintenance 5 2 Operational Check 5 3 Recalibration 5 3 Batteries 5 3 Detector Model 44 9 Tube Replacement Procedure 5 4 Hadiation Basics 6 Radiation and Life 6 1 The Unstable Atom 6 2 Radioactive Decay 6 3 lo
35. R CPM selects the display time base for the current detector setup This time base only applies if the units are set to C Counts time The time base for R hr and Sv h is fixed in hr For true reading pulser calibration cpm or cps calibrations set the Calibration Constant CC parameter 2 to read 1 For geometry calibrations the detector efficiency can be entered for CC Example For alpha scintillation detector with 25 2 efficiency enter 250 x 10 in the CC parameter setup The display time base may be set to seconds s minutes m Ludlum Measurements Inc Page 8 4 June 2011 Model 2241 2RK Technical Manual Section 8 POSITION 5 AUDIO DIVIDE BY selects the audible clicks per event division rate for the current detector setup If the AUD ON OFF switch is in the OFF position no audible clicks per event will be heard This parameter ranges from 0 Divide By 1 1 Divide 10 2 Divide 100 3 Divide 1000 POSITION 6 RESPONSE TIME allows changing the time constant for the current detector setup If the response 15 set to 0 the Model 2241 2 automatically calculates for vatiable mode the time constant based on the incoming cps If a variable of 1 199 is entered for TC the response time becomes fixed Variable Response Response time is varied in proportion to the incoming count rate The 2 position F S Fast Slow toggle switch selects the maximum time constant TC for
36. Radiation and Li Radiation 1s energy traveling through space Sunshine is one of the most familiar forms of radiation It delivers light heat and suntans We control its effect on us with sunglasses shade air conditioners hats clothes and sunscreen There would be no life on earth without lots of sunlight but we have increasingly recognized that too much of it on our bodies is not a good thing In fact it may be dangerous so we control our exposure to it Sunshine consists of radiation in a range of wavelengths from long wave infrared to short wavelength ultraviolet which creates the hazard Beyond ultraviolet are higher energy kinds of radiation that are used in medicine and which we all get in low doses from space from the air and from the earth Collectively we can refer to these kinds of radiation as ionizing radiation can cause damage to matter particularly living tissue At high levels it is therefore dangerous so it is necessary to control our exposure Background radiation is that which is naturally and inevitably present in out environment Levels of this can greatly People living in granite areas on mineralized sands receive mote terrestrial radiation than others while people living or wotking at high altitudes receive more cosmic radiation A lot of our natural exposute is due to radon a gas which seeps from the earth s crust and is present in the air we breathe Page 6 1 June 2011 Model
37. Self biased amplifier U021 provides gain in proportion to R022 divided by R025 Transistor pins 4 5 and 6 of 0021 provide amplification Pins 10 15 of U021 are coupled as a constant current source to pin 6 of 0021 output is self bias to 2 Vbe approximately 1 4 volts at pin 7 of 0021 This provides just enough bias current through pin of U021 to conduct all of the current from the constant current source Positive pulses from pin 7 of 0021 are coupled to the discriminator 0011 through R031 and C012 Discriminator Positive pulses from amplifier 0021 are coupled to pin 2 of 0011 comparator The discrimination level is set by the DISC control connected to pin 3 of 0011 As the positive pulses at pin 2 of 0011 increase above DISC reference at pin 3 pin 1 goes low producing low pulse Pin 1 of 0011 is normally held high 4 5 volts by R014 The low pulse from pin 1 of 0021 15 coupled to univibrator 0001 17001 shapes and fixes the pulse width to approximately 10 us The univibrator is configured in the non retriggerable mode Negative pulses from pin 9 of U001 are coupled to the for counting Low Voltage Supply Battery voltage is coupled to DC DC converter U231 U231 and related components provide 5 V to power the op amps and logic circuitry R135 and R136 provide voltage division for low battery detection Pin 6 of 0231 provides a low signal when the battery voltage decreases to 2 2 0 1 U121 provides th
38. ample 26 427 RR 440 C s CO I 60 Place detector in the high field and enter the counts per second Equation 8 counts CORR DAMPI hi count time 5 Counts second sample in high field of 200 mR hr Example 563 CORR n gt 5830 Insert the values calculated in equations 5 6 7 and 8 and solve for Equation 9 RR m X CAL w units ae T CAL CORR lo 5 1 e 5830 2 22 10 _ 55 6 x JO 262 x 8 fa Py 10 Solve for a Equation 10 units x count CAL CORR CAL i X CORR ji CU 5 1 55 6 x 10 x 5830 2 22 x 10 x 5830 31 1 x107 Ludlum Measurements Inc Page 8 16 June 2011 Model 2241 2RK Technical Manual Section 8 Enter the results of equations 9 and 10 into equation 11 to solve for DT Equation 11 pr 5 count Example 6 ED 31 1x10 Solve for Equation 12 units x CAL lo 7 CAL lo X CORR lo DT Example f 2 22 x 10 2 22 x 10 5x 440 x84 x 10 2 14 x 105 s Enter the result of equation 12 into Equation 13 Jf z units and solve for CC Example CC E 206 10 2 14 x 10 Enter the CC and DT values positions 1 and 2 of FUNCTION switch derived from the equations above Perform an R hr calibration as described in the previous subsection in order to ensure that the instrument and detector have been correctly cal
39. azardous live voltage before accessing the internal components This symbol appears on the front panel Note the following precautions Warning The operator is strongly cautioned to take the following precautions to avoid contact with internal hazardous live parts that are accessible using a tool 1 Turn the instrument power OFF and remove the batteries 2 Allow the instrument to sit for one minute before accessing any internal components The crossed out wheelie bin symbol notifies the consumer that the product is not to be mixed with unsorted municipal waste when discarding Each material must be separated The symbol is placed on the battery compartment See Section 9 Recycling for further information Maintenance Instrument maintenance consists of keeping the instrument clean and periodically checking the batteries and the calibration The Model 2241 2 instrument may be externally cleaned with a damp cloth using only water as the wetting agent Do not immerse the instrument in any liquid Observe the following precautions when cleaning 1 Turn the instrument OFF and remove the batteries 2 Allow the instrument to sit for one minute before performing any external cleaning or accessing internal components for maintenance Page 5 2 June 2011 Model 2241 2RK Technical Manual Section 5 OPERATIONAL CHECK An instrument operational check should be performed prior to each use by exposing the detector to the
40. counts for the CC and DTC algorithm These calculations require an unknown variable Dead Time Typical dead times for some of the standard LMI detectors are referenced in the table at the end of this section The count field should be a field which yields between 2 and 5 count loss count field CP should be a field that yields between 30 and 60 count loss Page 8 13 June 2011 Model 2241 2RK Technical Manual Section 8 Reference the table at the end of this section to determine the cps exposute rate cps ER The conversion can be determined by placing the detector in a radiation field cps which produces from 50 to 200 cps ps ER Calculate the count exposure rate radiation field in exposure rate units using the equation to the left For example exposing a LMI Model 44 9 to a 2 mR hr field yields approximately 110 cps so that 110 cps 55 cps mR hr 2 mR hr The typical dead time for M44 9 is approximately 85 us Therefore using 85 us for DT in equations 1 4 the 2 field should be between 240 and 619 cps and the field is between 5040 and 17 650 cps Dividing the cps values by the 55 cps mR hr conversion equates to between 4 11 mR hr for the field and 91 320 mR hr for the 7 field Select calibrated field between the and hi data points determined above lo CAL 8 mR hr hi 200 mR hr The following procedure outlines the hi lo method Abbreviations use
41. cted to eliminate delays in the exposure area 2 Distance In the same way that heat from a fire is less the further away you ate so the intensity of radiation decreases with distance from its source Distance is the easiest fastest and most practical way to limit exposure 3 Shielding Barriers of lead concrete or water give good protection from penetrating radiation such as gamma rays Highly radioactive materials therefore often stored ot handled under water by remote control in rooms constructed of thick concrete lined with lead Ludlum Measurements Inc Page 6 11 June 2011 Model 2241 2RK Technical Manual Section 6 Ludlum Measurements Inc Standards and Regulation Much of the evidence that has led to today s standards derives from the atomic bomb survivors in 1945 which were exposed to high doses incurred in a very short time In setting occupational risk estimates some allowance has been made for the body s ability to repair damage from small exposures but for low level radiation exposure the degree of protection may be unduly conservative Most countries have their own systems of radiological protection which are often based on the recommendations of the International Commission on Radiological Protection ICRP The authority of the ICRP comes from the scientific standing of its members and the merit of its recommendations Who is in charge Ultimately you are All of the sources of radia
42. d units Sv R counts CAL field calibration point CAL hr field calibration point CORR recorded field at low calibration point recorded field at high calibration point DT dead time constant entered into Model 2241 CC calibration constant entered into Model 2241 fiand a are intermediate steps in calculating DT Ju is an intermediate step in calculating CC Ludlum Measurements Inc Page 8 14 June 2011 Model 2241 2RK Technical Manual Section 8 CC and DTC Algorithm Equations 5 and 6 convert units per time R hr Display Units to units per second units units time second Insert the cps data point 8 mR hr for the Model 44 9 example determined from equations 1 and 2 Equation 5 R Ih lm 0 008 CAL nbl m 2 22 x 0 s 605 Insert the cps hi data point 200 mR hr for the Model 44 9 example determined from equations 3 and 4 Equation 6 R 18 0 200 55 6 p CAL LT Pl a x10 5 Place the detector the low field and enter the counts per second Equation 7 AMP Lio counts CORR AMPLe count time S Note The low field count sample should be 2 3000 counts Use the Scaler and adjust the count time to accumulate count 2 3000 Ludlum Measurements Inc Page 8 15 June 2011 Model 2241 2RK Technical Manual Section 8 As an example assume a 60 second count sample in a low field of 8 mR hr Ex
43. del 2241 2 Response Kit the pancake detector Model 44 9 must be used for detection of alpha Keep in mind that moisture or dirt may block alpha particles making them impossible to be measured shielding material must be removed from the suspected source Ensute that the instrument F S switch is in the F position When sutveying for alpha it is very important to get the window of the detector within three quarters inch of the sutface to be sutveyed Move the detector over the area to be measured as slowly as possible typically one to two inches per second keeping in mind that the instrument response time varies from 2 to 50 seconds Beta detect beta the pancake detector Model 44 9 must be used Move the detector over the area to be measured as slowly as possible the instrument response time vaties from 2 to 50 seconds Shielding may be utilized to determine the type of source alpha or beta Take a measurement with no shielding in place then another with a piece of paper or other thin material placed over the suspected source Page 2 4 June 2011 Ludlum Measurements Inc Model 2241 2RK Technical Manual Section 2 Compare the first reading with the second to determine the amount of alpha and beta contribution This will be a very rough number Gamma and X ray For gamma and high energy X ray the gamma scintillator Model 44 2 must be used This detector is approximately 50 times more sensiti
44. e 2 5 reference for the and DISC control references Page 7 1 June 2011 Model 2241 2RK Technical Manual Section 7 Ludlum Measurements Inc High Voltage Supply High voltage 15 developed by blocking oscillator Q241 7141 and C244 and rectified by voltage multiplier CRO41 CR043 C041 C043 and C141 High voltage increases as cutrent through R241 increases with maximum output voltage with Q241 saturated High voltage is coupled back through R034 to op amp pin 2 of U131 Resistor network R027 R132 completes the HV division circuit to ground 027 provides HV limit from 1250 2400 when the HV control on the calibration board is at maximum The regulated HV output is controlled by the HV1 and 2 potentiometers located under the CAL cover on the front panel This control provides the reference for comparator pin 3 0131 During stable operation the voltage at pin 2 of U131 will equal the voltage at pin 3 of U131 Pin 1 of U131 will cause conduction of Q141 to increase or decrease until the HV finds level of stability Detector Overload voltage drop is developed across 031 and sensed by comparator pins 5 6 and 7 of U131 as detector current increases When the voltage at pin 5 of U012 goes below 6 7 goes low signaling 0111 uP to send the OVERLOAD alarm to the LCD OVL underneath CAL cover control provides adjustment for the ovetload set point Microprocessor uP U111 controls all of the data
45. e silenced enabled via this front panel toggle switch audible alarm is independent of the AUD ON OFF switch and will override the audible clicks per event An audible alarm can only be silenced by depressing the RESET button F S Fast Slow Response Switch a two position toggle switch that selects fast or slow counting response time Page 4 2 June 2011 Model 2241 2RK Technical Manual Section 4 Variable Response The F position allows the time constant TC to vaty from 1 to 10 seconds while the S position varies from 1 to 30 seconds The response time is automatically adjusted in proportion to the incoming count rate between the F S TC variables Fixed Response The F position corresponds to the selected fixed response time TC The position is five times slower than the selected fast TC LIGHT LCD Backlight A pushbutton switch when depressed illuminates the LCD for pre programmed time backlight ON time can be selected between 5 and 240 seconds during the parameter setup RESET Pushbutton Switch In the non alarm condition depressing the RESET switch resets the ratemeter display to the minimum display readout In an alarm condition ratemeter or scaler depressing RESET will silence the audible alarm Depressing RESET a second time will reset the ratemeter alarm and or alert condition The scaler alarm can only be reset by depressing the scaler COUNT switch located in the end of the Model 2241 2 hand
46. ge and under responding by a factor of 0 5 above 1 MeV when normalized to The response of this detector is nominally linear within 10 from 5 uR hr to 50 mR hr This detector consists of a one inch 2 54 cm diameter one inch thick Nal crystal coupled to a photomultiplier tube and 1s housed in 0 16 cm 0 062 in thick aluminum housing Recommended instrument sensitivity is approximately 10mV or higher Operating voltage varies from one detector to another Common applications for this detector include background radiation monitoring and low level radiation detection Page 1 3 June 2011 Model 2241 2RK Technical Manual Section 2 Section Ludlum Measurements Inc Getting Started Unpacking and Repacking Remove the calibration certificates and place them a secure location Remove the instrument detectors and accessoties batteries cable and ensure that all of the items listed on the packing list are in the carton Check individual item serial numbers and ensure calibration certificates match The Model 2241 2 serial number is located on the front panel below the battery compartment Most Ludlum Measurements Inc detectors have a label on the base or body of the detector for model and serial number identification Important If multiple shipments are received ensure that the detectors and instruments are not interchanged Each instrument is calibrated to specific detectors and is not interc
47. hangeable To return an instrument for repair or calibration provide sufficient packing material to prevent damage during shipment Also provide appropriate warning labels to ensure careful handling Include detector s and related cable s for calibration Include brief information as to the reason for return as well as return shipping instructions Return shipping address Customer name or contact Telephone number Description of service requested and all other necessary information Battery Installation Ensure the OFF SCALER RATEMETER switch is in the OFF position Open the battery lid by turning the quarter turn thumb screw counterclockwise Page 2 1 June 2011 Model 2241 2RK Technical Manual Section 2 Install two D size batteries in the compartment Note the gt matks inside the battery door Match the battery polarity to these matks Close the battety box lid Note The center post of a D size battery is positive Operational Check Connect a detector to the Model 2241 2 by using the cable provided firmly pushing the connectors together while twisting clockwise until the connector M latches one quarter of a turn The diagram to the left illustrates how this is done Next place the DETECTOR SELECTOR switch in the appropriate N position Note The Model 2241 2 front panel when part of a tesponse kit includes a color code at the detector selector switch which cotre
48. he HV potentiometers make note of the following precautions Use a Ludlum Model 500 Pulser or high impedance voltmeter with a high voltage probe to measure the high voltage at the detector connector If a Ludlum Model 500 Pulser is not available ensure that the impedance of the voltmeter used is 1000 megohms or greater HV1 HV2 multi turn potentiometers approximately 20 revolutions that varies the detector voltage from 200 to 2500 volts The maximum high voltage output is adjusted by the HV LIMIT potentiometer located on the internal main board OVL Detector Overload a multi turn potentiometer approximately 20 revolutions that adjusts the detector current level that must be exceeded to initiate an OVERLOAD alarm This control adjusts the current level discrimination point from 0 5 and 40 microamperes corresponding to the specific detector saturation point Main Board Controls Note To access the internal circuit boards unlatch the latches at each end of the Model 2241 2 Carefully separate the top chassis from the bottom cover referred to as a can The can has the audio speaker unimorph with a two conductor cable attached to the main board The audio plug may be disconnected during the internal control adjustments HV LIMIT R027 a multi turn potentiometer approximately 20 revolutions sets the maximum HV limit with the front panel HV control adjusted to the maximum clockwise position It is adjustable from 1250
49. he Software provided Customer affixes to such copy all copyright confidentiality and proprietary notices that appear on the original EXCEPT AS EXPRESSLY AUTHORIZED ABOVE CUSTOMER SHALL NOT COPY IN WHOLE OR IN PART SOFTWARE OR DOCUMENTATION MODIFY THE SOFTWARE REVERSE COMPILE OR REVERSE ASSEMBLE ALL OR ANY PORTION OF THE SOFTWARE OR RENT LEASE DISTRIBUTE SELL OR CREATE DERIVATIVE WORKS OF THE SOFTWARE Customer agrees that aspects of the licensed materials including the specific design and structure of individual programs constitute trade secrets and or copyrighted material of Ludlum Customer agrees not to disclose provide or otherwise make available such trade secrets or copyrighted material in any form to any third party without the prior written consent of Ludlum Customer agrees to implement reasonable security measures to protect such trade secrets and copyrighted material Title to Software and documentation shall remain solely with Ludlum LIMITED WARRANTY Ludlum warrants that for a period of ninety 90 days from the date of shipment from Ludlum i the media on which the Software is furnished will be Ludlum Measurements Inc Page 8 21 June 2011 Model 2241 2RK Technical Manual Section 8 free of defects in materials and workmanship under normal use and ii the Software substantially conforms to its published specifications Except for the foregoing the Software is provided AS IS This limited warranty extends onl
50. hr mR hr uR hr Sv h mSv h or uSv h C m kC m C s or kC s The bottom part of the readout displays the ALARM ALERT OFLOW OVERLOAD annunciators and the low battery icon COUNTING indicates that the scaler mode has been initiated and is in the counting process Display Status Definitions ALARM Ratemeter or scaler count has increased above the preset alarm threshold An audible continuous tone will accompany the latching ALARM condition Depressing RESET will acknowledge the audible ratemeter and or scaler alarm Depressing RESET a second time will reset the ratemeter reading and ratemeter alarm To reset the scaler ALARM depress the COUNT switch located in the carrying handle to re initiate the scaler count cycle ALERT Ratemeter count has increased above the preset alert threshold To reset ALERT condition press RESET once if in the non alarm condition and twice if in an alarm condition The first depression in the alarm condition acknowledges the audible alarm The ratemeter will reset to the minimum displayable reading each time the alert 15 reset OFLOW Overflow In RATEMETER mode it indicates that the incoming count exceeds the capability to display stable or reliable readings cotresponding to the radiation level being measured The overflow symbol will appear when the ratemeter exceeds 100 kcps or if the dead time correction is greater than 75 OFLOW will appear in the SCALER Page 4 1 June 2011 Model
51. ibrated Ludlum Measurements Inc Page 8 17 June 2011 Model 2241 2RK Technical Manual Section 8 Model 44 9 Detector Parameter Setup FUNCTION PARAMETER 1 0084 5 2 0206 ng 4 N A 5 8 as desired B C as desired D F if applicable Typical Count Rate and Dead Time for LMI Detectors DEAD TIME MODEL amp TYPE COUNT RATE in us microseconds 44 6 GM 20 cps mR hr 90 110 us 44 9 GM 55 cps mR hr 80 90 us 44 7 GM 35 cps mR hr 240 290 us 133 2 GM 17 5 cps mR hr 40 55 us 133 4 GM 2 cps mR hr 40 55 us 133 6 GM 0 3 cps mR hr 40 55 us 44 2 Gamma Scint 2800 cps mR hr 8 12 ust 44 10 Gamma Scint 15 000 cps mR hr 18 20 us 44 3 Low Energy Gamma Scint N A operated in Counts units mode 8 12 ust 44 21 Beta Gamma Scint N A operated in Counts units mode 8 12 ust 43 5 Alpha Scint N A operated in Counts units mode 20 28 us Note The data represented in the table above is typical Actual values may vary among detector and instrument combinations This table represents some of the common detectors operated with the Model 2241 2 Consult the LMI sales department information concerning detectors not listed in the table above The dead time values for these scintillation detectors are due to the dead time of the Model 2241 2 electronics Ludlum Measurements Inc Page 8 18 June 2011 Model 2241 2RK Technical Manual Section 8 DETECTOR OVERLOAD OVL CALIBRATION Note The detector operating voltage HV mus
52. itch SCALER RATEMETER to the RATEMETER position Select position on the rotary switch located on the front panel Select FUNCTION switch positions 1 6 and adjust for the following parameters Switch Pos Parameter Function 1 0000 s Dead Time 2 0100 2 Calibration Constant 3 c Display Units 4 m Timebase 5 1 Audio Divide by 6 000 s Response Time Position 7 selects the desired ratemeter ALERT and ALARM ttip points If the parameters ate undetermined arbitrarily choose 0050 kC m for the alarm and 0045 kC m for the alert to confirm operation of the alert alarm function Position 8 selects the scaler ALARM parameter and the scaler count time If the values are unknown set the scaler alarm to 4500 4 and the count time to 0060 60 second count time Position 9 is not used and position A is not used Switch to position and enter 715 for 15 second backlight ON time Switch to position C and enter 00 0 C m for the minimum displayable value Select position 0 to return to normal operation Connect the Model 500 Pulser to detector input and adjust and DISC to the specific detector operating parameters Ludlum Measurements Inc Page 8 10 June 2011 Model 2241 2RK Technical Manual Section 8 Ludlum Measurements Inc Adjust the pulser amplitude to 1 5 times the Model 2241 2 discrimination level Adjust the pulser output to 800 cpm and confirm that the Model 224
53. ition Count time is adjustable Calibration Controls accessible from the front of the instrument protective cover provided These controls are preset at the factory calibration lab and should not be adjusted by field personnel Discriminator Input Sensitivity adjustable from 2 to 100 mV negative pulse response Overload indicated by OVERLOAD on the display adjust able depending on the detector selected High Voltage two independent controls each adjustable from 200 2500 volts two separate set points for DET1 and DET2 regulated within 0 2 at 1000 Vdc maximum load of 50 uA RESET a pushbutton for zeroing the display acknowledging and or resetting the alarm Page 3 1 June 2011 Section 3 Model 2241 2RK Technical Manual Section 3 Removable Switchboard Adjustable Parameters Ludlum Measurements Inc Note The RESET button only silences the alarm in the current mode that the instrument is in For example the RESET button will not affect the scaler alarm if the instrument is in the tatemeter mode LIGHT display backlight activated by pushbutton Audio built in audio speaker unimorph with AUD ON OFF switch greater than 60 dB at 0 61 m 2 ft Alert Alarm indicated by either an ALERT or ALARM enunciator on the display RATEMETER mode only and by an audible tone Power two each cell batteries housed in an externally accessible sealed compartment Current draw is approximately 35 mA
54. le Note The RESET button only silences the alarm in the current mode that the instrument is in For example the RESET button will not affect the scaler alarm if the instrument is in the tatemeter mode Scaler Switch pushbutton located in the end of the Model 2241 2 carrying handle which when depressed initializes the start of the scaler count accumulation for the preset scaling time The SCALER RATEMETER switch must be in the SCALER position to initiate the counting cycle scaler display uses the two digits in the lower right hand corner for the two most significant digits of the six digit readout Scaling time can be set from 1 to 9999 seconds in the parameter setup by way of the switch board Depressing the COUNT switch after a scaler ALARM will reset the scaler display to zero resetting the alarm Front Panel Calibration Controls Note Remove the front panel calibration cover to expose the following calibration controls Ludlum Measurements Inc Page 4 3 June 2011 Model 2241 2RK Technical Manual Ludlum Measurements Inc DISC 1 and DISC 2 Discriminator 1 and 2 two independent multi turn potentiometers approximately 20 revolutions used to vary the detector pulse counting threshold from 2 to 100 millivolts for DET1 and DET2 respectively A Ludlum Model 500 Pulser or equivalent should be used in checking or adjusting the pulse discrimination parameter Note When making adjustments to t
55. lled by adjusting either the instrument sensitivity ot the high voltage HV controls the gain of the detector and DISC Discriminator controls the instrument counting threshold sensitivity In the special case of GM detectors a minimum voltage must be applied to establish the Geiger Mueller characteristic Further changes in HV will have effect on this type of detector G M Detectors The output pulse height of the GM detector 15 not proportional to the energy of the detected radiation Adjusting DISC will have minimal effect on observed count rate unless the DISC setting is so low that the instrument will double pulse Ludlum Measurements Inc Page 8 8 June 2011 Model 2241 2RK Technical Manual Section 8 For most GM detectors set DISC for 30 40 millivolts and adjust HV to the GM detector recommended high voltage Most GM detectors operate at 900 volts although some miniature detectors operate at 450 550 volts If a recommended setting is unavailable plot count rate versus HV to produce a plateau graph Adjust the for 25 50 volts above the knee or start of the plateau For mixed detector use both sensitivity and high voltage may be tailored for other detectors as long as the GM detector is operated within the recommended voltage range Caution must be observed in lowering the input sensitivity to ensure that the counter does not double or multi pulse Alpha Air Proportional Detectors For air proportional alpha detector
56. m Model 44 9 is calibrated with Model 2241 2 in the R hr units display utilizing DT The upper linear operating point is 400 mR hr for the Model 44 9 Place the detector at the 1000 mR hr point and adjust the OVL control to initiate the OVERLOAD alarm Place the detector in the 600 700 mR hr field and ensure that the OVERLOAD is off Ludlum Measurements Inc Page 8 19 June 2011 Model 2241 2RK Technical Manual Ludlum Measurements Inc Section 8 The detector overload or saturation point for alpha and or beta scintillation detectors is when the detector face Mylar has been punctured allowing light to saturate the photomultiplier tube PMT The pulse output will decrease or even appeat non responsive to any radiation activity depending upon the size of the puncture and the light intensity to the PMT Expose the detector PMT to a small light leak by loosening the detector window Some scintillators incorporate a screw in the detector body which when removed will simulate a detector face puncture The ratemeter readout should start to decrease as the light saturates the PMT Adjust the OVL control until the OVERLOAD just appears on the display Reseal the light leak connection and expose the detector to a radiation source that will produce a near full scale reading Confirm that the OVERLOAD alarm does not initiate Readjust the OVL control as required Loading Default Parameters To load the default parameters for all detect
57. ma Scintillator 2 x 205A Ludlum Measurements Inc Technical Manual Reference UNIT UNIT Description Completely Assembled Model 44 9 Alpha Beta Gamma Detector DETECTOR BODY HANDLE GRIP GM TUBE LND 7311 TGM N1002 SOCKET SET SCREWS 10 34 X 1 4 3 EACH PENCIL CLIP RESISTOR 3 53 MEGOHMS CONNECTOR UG 706 U HV WIRE PROTECTIVE SCREEN RED PROTECTIVE CAP Completely Assembled Model 44 2 Gamma Scintillator DETECTOR BODY END CAP Section 10 Part Number 47 1539 2002 109 7002 426 01 5008 17 8560 01 5237 10 7044 13 7751 21 9312 21 9586 03 5476 47 1532 2002 084 01 7002 029 02 2 5 2 5 cm 1 x 1 in Nal CRYSTAL 40 5154 3 8 cm 1 5 in TUBE SOCKET ASSY TUBE SHIELD PM TUBE CONNECTOR UG 706 U TEFLON WIRE 4 ea 26 BLACK WIRE 4 ea LUG SCREWS 4 ea SPONGE 6 ea XTAL SIDE SPONGE 2 ea Completely Assembled Tube Socket Circuit Boatd Included in PM TUBE 01 5742 Page 10 7 4002 510 40 4006 01 5742 13 7751 21 9362 21 9558 18 8766 17 8811 7002 029 05 7002 276 5002 502 June 2011 Model 2241 2RK Technical Manual Section 11 Section Ludlum Measurements Inc Drawings Main Circuit Board Drawings 408 x 223 3 sheets Main Circuit Board Component Layout Drawing 408 x 224 Calibration Board Drawing 408 x 127 Calibration Board Component Layout Drawings 408 128 2 sheets Displa
58. mperatures battery seal failure can occur at temperatures as low as 38 100 F Ludlum Measurements Inc Page 5 3 June 2011 Model 2241 2RK Technical Manual Section 5 DETECTOR MODEL 44 9 TUBE REPLACEMENT PROCEDURE Consult the Model 44 9 Alpha Beta Gamma Detector drawing in Section 11 of this manual to perform the following Caution The mica window of this tube is extremely thin and can easily break There is also a thin layer of material to prevent UV interference This material may come off if touched causing the detector to malfunction DO NOT TOUCH 1 Remove the back plate by removing the three screws 2 Loosen the three set screws on the side of the tube housing 3 Remove the old tube from the detector housing 4 Remove the anode clip from the old tube 5 Push the clip onto the anode housing Note Do not over flex the wire when installing the clip 6 Carefully install the tube with the window face down in the housing Tighten the set screws evenly The tube should be flush against the screen 7 Replace the back plate and the retaining screws 8 The detector is now ready for use Note The instrument and detector will need to be recalibrated once the above procedure is complete Ludlum Measurements Inc Page 5 4 June 2011 Model 2241 2RK Technical Manual Section 6 Section Ludlum Measurements Inc Radiation Basics Radiation and Life Adapted from Eric Hall book
59. nd dose rates to individuals 1000 rem as a short term and whole body dose would cause immediate illness such as nausea decreased white blood cell count and subsequent death within a few weeks Between 200 and 1000 rem in a short term dose would cause severe radiation sickness with increasing likelihood that this would be fatal 100 rem in a short term dose is about the threshold for causing immediate radiation sickness in a person of average physical attributes but would be unlikely to cause death Above 100 rem severity of illness increases with dose If doses greater than 100 rem occur over a long period they are less likely to have early health effects but they create a definite risk that cancer will develop many years later Above about 10 rem the probability of cancer rather than the severity of illness increases with dose The estimated risk of fatal cancer is 5 of every 100 persons exposed to a dose of 100 rem i e if the normal incidence of fatal cancer were 25 this dose would increase it to 30 5 rem is conservatively the lowest dose at which there is any evidence of cancer being caused in adults It is also the highest dose which is allowed by regulation in any one year of occupational exposure Dose rates greater than 5 rem yr atise from natural background levels in several parts of the world but do not cause any discernible harm to local populations Ludlum Measurements Inc Page 6 7 June 2011 Model 2241
60. ne The SCALER alarm condition will also display the word ALARM and produce the same audible tone Both audible alarms may be silenced acknowledged by depressing the RESET switch All alarms are concurrent Page 1 1 June 2011 Model 2241 2RK Technical Manual Section 1 Ludlum Measurements Inc Other features include 1 Dead Time Correction DTC to compensate for detector dead time 2 audible click per event with programmable 1 10 100 and 1000 divide by 3 LCD backlight with programmable ON time 4 programmable fixed or variable response time and 5 count overflow visual alarm indicating that the counting circuitry is nearing the maximum counting capability All of the features described above may be programmed manually using the internal switch board or by computer through the RS 232 port Two different detector operating parameters may be stored in non volatile memory The switch board can be removed after entering or changing parameters to prevent tampering with setup parameters A regulated high voltage power supply and two independent set point controls adjustable from 200 to 2500 volts with detector overload detection and adjustable discrimination levels add versatility to the instrument This supports operation for a broad range of detectors and connecting cable lengths All of the calibration controls are covered to prevent any inadvertent adjustment to the detector operating parameters The instrument is powered
61. nizing Radiation 6 4 Measuring lonizing Radiation 6 5 What are the Health Risks from lonizing Radiation 6 6 How Much lonizing Radiation is Dangerous 6 7 Ludlum Measurements Inc June 2011 Model 2241 2RK Technical Manual Background Radiation Manmade Radiation Protection from Radiation Standards and Regulation Who is in Charge Technical Principle of Operation Main Board Switch Board Display Board Instrument Setup amp Calibration Factory Settings Entering or Changing Switch Board Parameters The Function Switch Function Switch Position Descriptions and Variables Calibration General Detector Setup Information Counts per minute C m Calibration R hr Calibration Determining CC and DTC Detector Overload OVL Calibration Loading Default Parameters Software License Agreement Recycling Parts List Model 2241 2 Survey Meter Main Circuit Board Drawing 408 x 223 Calibration Board Drawing 408 x 127 Display Board Drawing 408 x 259 Switch Board Drawing 408 x 45 Chassis Wiring Diagram Drawing 408 x 131 Model 44 9 Alpha Beta Gamma Detector Pancake Model 44 2 Gamma Scintillator Drawings Ludlum Measurements Inc June 2011 6 10 6 11 6 11 6 12 6 12 70 10 1 10 1 10 3 10 4 10 5 10 5 10 7 10 7 77 Model 2241 2RK Technical Manual Section 1 Section Ludlum Measurements Inc Introduction microprocessor based digital Scaler Ratemeter as well as scintillation and Geiger Mueller
62. not to be mixed with unsorted municipal waste when discarding Each material must be separated The symbol will be placed near the AC receptacle except for portable equipment where it will be placed on the battery lid The symbol appears as such x Page 9 1 June 2011 Model 2241 2 Section Model 2241 2 Survey Meter Main Circuit Board Drawing 408 x 223 CAPACITORS Ludlum Measurements Inc Technical Manual Parts List Reference UNIT BOARD C1 C3 001 002 C011 C012 C021 C031 C032 C033 041 043 101 121 122 123 131 132 133 134 135 136 137 C138 C139 C141 Description Completely Assembled Model 2241 2 Survey Meter Completely Assembled Main Circuit Board 50V 50V 100V 0 001uF 100V 50V 100pF 3KV 0 0047uF 100pF 3KV 0 0047uF 0 0047uF 47uF 10V 47uF 10V 2 100V 0 0047uF 50V 0 01uF 50V 47uF 10V 0 01uF 50V 47uF 10V 100pF 100V 0 001uF 100V 0 0047F 3KV Page 10 1 Section 10 Part Number 48 2731 5408 223 04 5663 04 5663 04 5660 04 5659 04 5663 04 5532 04 5547 04 5532 04 5547 04 5547 04 5666 04 5666 04 5658 04 5547 04 5663 04 5664 04 5666 04 5664 04 5666 04 5661 04 5659 04 5547 June 2011 Model 2241 2 TRANSISTORS INTEGRATED CIRCUITS DIODES POTENTIOMETERS TRIMMERS RESISTORS Ludlum
63. on requirements are not specified at the time the instrument is ordered calibration will be made based on the default settings shown below DETH1 DETZ2 Color Dot Red Yellow Probe model 44 9 44 2 Units Time base R hr Rate Alarm 50kcpm 50 wR hr Rate Alert 20 kcpm 20 uR hr Scaler Alarm 85000 85000 Scaler count time 12 sec 12 sec Entering or Changing Switch Board Parameters On the switch board select the desired parameter to enter or change by using the corresponding FUNCTION switch position Depress the ENTER button and a character on the LCD will start to flash The flashing character indicates that the program is in the parameter change mode To change the character press the UP button until the desired variable is reached To shift to another character increment the LEFT pushbutton until the desired character 15 reached The LEFT pushbutton switch enables the operator to sequence through all the characters on the LCD associated with a particular parameter Page 8 1 June 2011 Model 2241 2RK Technical Manual Section 8 Once the desired data is entered depress the ENTER button The LCD characters should stop flashing and the new parameter data should display Note The DETECTOR SELECT toggle switch allows the Model 2241 2 to have two sets of operating parameters THE FUNCTION SWITCH FUNCTION Switch 16 position rotary switch labeled 0 9 and A F This switch selects a parameter set
64. on a check source to produce a ratemeter reading of 100 to 2000 counts per minute or 10 100 uR hr While observing the ratemeter fluctuations select between the fast and slow response time F S positions to observe variations in the display The S position should respond approximately five times slower than the position for fixed response mode and three times slower when in variable response mode The slow response position is normally used when the Model 2241 2 1s displaying low numbers that require a more stable display The fast response position 15 used at high count levels Page 2 3 June 2011 Ludlum Measurements Inc Model 2241 2RK Technical Manual Section 2 Move the OFF SCALER RATEMETER switch to the SCALER position Depress the COUNT switch located the end of the carrying handle in order to initiate a count cycle The word COUNTING should be flashing on the LCD during the count cycle and should disappear at the end of the predetermined count time If a scaler ALARM condition occurs the RESET switch can be depressed to acknowledge the alarm however the COUNT switch must be depressed to clear the visual ALARM and to restart the count cycle Depress and release the LIGHT switch The backlight located behind the LCD should illuminate for pre programmed ON time Select the desired F S AUD ON OFF and RATEMETER SCALER patameters and proceed to use the instrument Survey Techniques Alpha When using the Ludlum Mo
65. or setups hold down the UP pushbutton on the switch board until DEF is displayed on the LCD The table on the following page shows the default values Model 2241 2 Cpm mR hr Setup 01 Setup 02 Dead Time 80 us 6 us Cal Const 100e 2 105e 8 Rate Alarm 50 0 kepm 50 uR hr Scaler Alarm 85000 85000 Count Time 12s 12s Time Base min 5 Units cpm R hr Audio Divide By 1 1 Response 0 0 Check Source 0 0 Percent CS 0 0 Rate Alert 20 0 kepm 20 uR hr Min Display 0 00 cpm 00 0 uR hr Baud Rate 9600 LCD Time Off 5s Detector 0 Page 8 20 June 2011 Model 2241 2RK Technical Manual Section 8 LUDLUM MEASUREMENTS INC i 501 OAK ST P O BOX 810 SWEETWATER TX 79556 325 235 5494 FAX 325 235 4672 Software License Agreement Rev number 1 0 Written by or Revised by Date 23 ag Approved by 27 j Date 204A BY INSTALLING THIS SOFTWARE YOU ARE CONSENTING TO BE BOUND BY THIS AGREEMENT IF YOU DO NOT AGREE TO ALL OF THE TERMS OF THIS AGREEMENT DO NOT INSTALL THE PRODUCT Single User License Grant Ludlum Measurements Inc Ludlum and its suppliers grant to Customer Customer a nonexclusive and nontransferable license to use the Ludlum software Software in object code form solely on a single central processing unit owned or leased by Customer or otherwise embedded in equipment provided by Ludlum Customer may make one 1 archival copy of t
66. otecting the environment and to comply with all regional national and international agencies that promote economically environmentally sustainable recycling systems To this end Ludlum Measurements Inc strives to supply the consumer of its goods with information regarding reuse and recycling of the many different types of materials used in its products With many different agencies public and private involved in this pursuit it becomes evident that a myriad of methods can be used in the process of recycling Therefore Ludlum Measurements Inc does not suggest one particular method over another but simply desires to inform its consumers of the range of recyclable materials present in its products so that the user will have flexibility in following all local and federal laws L udlum Measurements Inc supports the recycling of the electronic The following types of recyclable materials are present in Ludlum Measurements Inc electronics products and should be recycled separately The list is not all inclusive nor does it suggest that all materials are present in each piece of equipment Batteries Glass Aluminum and Stainless Steel Circuit Boards Plastics Liquid Crystal Display LCD Ludlum Measurements Inc products which have been placed on the market after August 13 2005 have been labeled with a symbol recognized internationally as the crossed out wheelie bin This notifies the consumer that the product is
67. pped from Ludlum Measurements Inc The following subsection deals with exposure rate calibration The detector Calibration Constant CC and Dead Time Correction are the two primary parameters used in the exposure rate calibrations R hr and Sv h These two constants are alternately vatied to achieve lineatity at the detector non linear operating regions An example of the Ludlum Model 44 9 GM detector calibration is given at the end of this section to illustrate the algorithm used in determining the CC and D TC variables The last subsection of calibration deals with the Detector Overload OVI GENERAL DETECTOR SETUP INFORMATION The operating point for the instrument and probes is established by setting the probe voltage and instrument sensitivity HV and DISC The proper selection of this point is the key to instrument performance Efficiency background sensitivity and noise ate fixed by the physical makeup of the given detector and rarely vary from unit to unit However the selection of the operating point makes a marked difference in the apparent contribution of these three sources of count In setting the operating point the final result of the adjustment is to establish the system gain so that the desirable signal pulses including background radiation are above the discrimination level and the unwanted pulses from noise are below the discrimination level and are therefore not counted The total system gain can be contro
68. r 8 15 uR hr If using a Ludlum Model 44 2 detector a typical reading would be 1 4 2 6 kcpm or 8 15 uR hr reference reading or readings with a check source should be obtained with the detector s in a constant and reproducible manner at the time of calibration at the time the instrument is received in the field If at any time the instrument fails to read within 20 of the reference reading when using the same check source it should be sent to a calibration facility for recalibration and or repair If desired multiple readings may be taken at different distances and or with different soutces so that other ranges or scales are checked Switch the AUD ON OFF switch to the ON position and confirm that the external unimorph speaker produces an audible click for each event detected audio divide by 1 parameter The AUD ON OFF switch will silence the clicks if in the OFF position however an audible alarm condition will still be heard Increase the source activity or lower the alert and alarm points to initiate an ALERT and ALARM condition Refer to Section 8 Entering or Changing Switchboard Parameters Depress the RESET switch to acknowledge the audible alarm Decrease the radiation activity below the ALERT and ALARM threshold and depress the RESET switch to clear the alarm conditions If an alarm condition is not present depressing the RESET switch the first time will reset the alert condition and zero the ratemeter Positi
69. rom low doses of radiation The prevailing assumption is that any dose of radiation no matter how small involves a possibility of risk to human health However there is no scientific evidence of risk at doses below approximately 5 rem in a short period of time or about 10 rem over a period of one year Higher accumulated doses of radiation might produce a cancer that would only be observed several up to 20 years after the radiation exposure This delay makes it impossible to say with any certainty which of many possible agents were the cause of a particular cancer In western countries about quarter of people die from cancers with smoking dietary factors genetic factors and strong sunlight being among the main causes Radiation is a weak carcinogen but undue exposure could certainly increase health risks Page 6 6 June 2011 Model 2241 2RK Technical Manual Section 6 On the other hand large doses of radiation directed specifically at a tumor are used in radiation therapy to kill cancerous cells and thereby often save lives usually in conjunction with chemotherapy or surgery Much larger doses are used to kill harmful bacteria in food and to sterilize bandages and other medical equipment Radiation has become a valuable tool in our modern world How Much lonizing Radiation is Dangerous Radiation levels and their effects The following table gives an indication of the likely effects of a range of whole body radiation doses a
70. s set the DISC for 2 millivolt discrimination Adjust HV until the detector just breaks down shown by a rapid increase of count rate without a source present Measure the HV output then decrease the setting to operate 100 volts below breakdown Proportional Detectors For proportional detectors set the DISC control for 2 millivolt discrimination neat maximum clockwise Expose the detector to a check source and plot count rate versus HV similar to the one in the figure below Refine the adjustment for optimum source efficiency with a minimum acceptable background count Scintillators Set the DISC for 10 millivolts Plot background and source counts versus HV to produce a plateau graph similar to the one in the figure Adjust the to 25 50 volts above the knee statt of the plateau This provides the most Backarouna stable operating point for the detector Source Enee 50 Volts COUNTS PER MINUTE C M CALIBRATION This procedure will setup the Model 2241 2 for the Counts minute C m mode of operation Refer to Section 8 Page 8 2 and following for more information on setup parameter variables A Ludlum Model 500 Pulser or equivalent is required If the Pulser does not have a high voltage display use a high impedance voltmeter with at least 1000 megohms input resistance to measure the detector high voltage Ludlum Measurements Inc Page 8 9 June 2011 Model 2241 2RK Technical Manual Section 8 Sw
71. s and therefore the low field must be at least 10 times the background count The following summary lists the calibration constraints Calibration and Dead Time Calibration Constraints FIELD CONSTRAINT BACKGROUND 10 times less than low field LOW FIELD Yields from 2 to 5 count loss HIGH FIELD Yields from 30 to 60 count loss This constraint only applies when using two sources two fields or a radiation range calibrated without background consideration Ludlum Measurements Inc Page 8 12 June 2011 Model 2241 2RK Technical Manual Equation 1 P 102 _______ VP 49 x DT Equation 2 LOs 19 DT Equation 3 CPS 30 1 2 3333 x DT Equation 4 1 5 CPS HI 60 DT Ludlum Measurements Inc Section 8 Preliminary CPS Setup Refer to Section 8 Subsection Function Switch Position Descriptions and Variables for cps readout variables Select position DET1 on the toggle switch located on the front panel Starting with FUNCTION switch position 1 enter the following variables SWIICH POS PARAMETER FUNCTION 1 0000s Dead Time 2 0100 2 Calibration Constant 3 Cf Display Units 4 m Timebase 5 N A Audio DivideBy 6 N A Response Time 7 N A Ratemeter Alm Alert 8 0060 s ScalerAlm Count Time 9 Not Used Not Used B LCD Backlight C 000 C s Set Minimum Display D F RS 232 Parameters The equations to the left Equations 1 4 determine the hi and radiation fields used to acquire
72. sponds to color coded detectors included in the kit This serves as a reminder quick reference of the set detector parameters for each position See Section 8 Subsection Factory Settings Page 8 1 for the color code Sw h Turn the OFF SCALER RATEMETER switch to the RATEMETER B B B H mmR hr position Notice that the display goes through an initialization kC ms sequence The display will show all 875 with decimal points Check __OFLOW ALERT ALARM to make sure all segments display as illustrated in the diagram to the OVERLOAD COUNTING 88 The LCD then displays the firmware number in the format YY The XX is the firmware number and the YY is the firmware version The figure to the left is for example only to illustrate location of display The minimum displayable value for example 00 0 uR hr should be shown When switched to the SCALER position a single 0 will be displayed Ludlum Measurements Inc Page 2 2 June 2011 Model 2241 2RK Technical Manual Section 2 In The display will auto range to the current level see figure at left When auto ranging down the Model 2241 2 uses multiples of 5 R hr This technique keeps the decimal point from jumping between numbers when viewing values around multiples of 10 Check for a proper background reading If using a Ludlum Model 44 9 detector a typical reading would be 25 50 cpm o
73. supplied check source confirming the proper reading on each scale See Section 2 Subsection Operational Check for further details RECALIBRATION Recalibration should be accomplished after any maintenance or adjustment of any kind has been performed on the instrument Battery and cable replacements of same length and exterior cleanings do not normally require the instrument be recalibrated Note Ludlum Measurements Inc recommends recalibration at intervals no greater than one year Check the appropriate local state and federal regulations to determine required recalibration intervals Ludlum Measurements offers a full service repair and calibration department We not only repair and calibrate our own instruments but most othet manufacturer s instruments as well See Section 8 Instrument Setup amp Calibration for further details on instrument calibration BATTERIES The batteries should be removed and the battery contacts cleaned of any corrosion at least every three months If the instrument has been exposed to a very dusty or corrosive atmosphere more frequent battery servicing should be used Use spanner wrench to unscrew the battery contact insulators exposing the internal contacts and battery springs Removing the handle will facilitate access to these contacts Note Never store the instrument over 30 days without removing the batteries Although this instrument will operate at very high ambient te
74. t be determined and adjusted before the OVL adjustment is performed If the HV 15 varied or another detector is substituted OVL must readjusted If the overload feature is not used adjust the control to the maximum counterclockwise position The detector overload circuit senses current flow through the detector As the radiation intensity is increased the detector may start to saturate decrease pulse production and the readout may decrease or read 0 But as the pulse output continues to decrease in the saturated field the detector current drain continues to increase This increase in current is detected by a comparator circuit which triggers the OVERLOAD enunciator on the LCD by way of the microprocessot For GM and gamma scintillation detectors the OVL trip point is adjusted to the point to where the readout no longer increases with increasing radiation intensity In the event that the overload point cannot be determined due to radiation field limitations adjust the ovetload point from 5 to 10 times the upper operating range of the detector Adjust the OVL control to the maximum counterclockwise position Place the detector in an increasing radiation field in which the readout no longer increases Adjust the OVL control until the OVERLOAD alarm appears Position the detector between the upper operating limit and the OVL set point and ensure the OVERLOAD alarm is defeated Adjust the OVL control accordingly Example Ludlu
75. tes are an average for all ages males and females and all forms of cancer There is a great deal of uncertainty associated with the estimate Risk from radiation exposure has been estimated by other scientific groups The other estimates are not the exact same as the BEIR V estimates due to differing methods of risk and assumptions used in the calculations but all are close Risk comparison The real question is How much will radiation exposure increase my chances of cancer death over my lifetime To answer this we need to make a few general statements of understanding One is that in the US the current death rate from cancer is approximately 20 so out of any group of 10 000 United States citizens about 2000 of them will die of cancer Second the contracting cancer is a random process Page 6 8 June 2011 Model 2241 2RK Technical Manual Section 6 Ludlum Measurements Inc where given a set population we can estimate that about 20 percent will die from cancer but we cannot say which individuals will die Finally that a conservative estimate of risk from low doses of radiation is thought to be one in which the tisk is linear with dose That is that the risk increases with a subsequent increase in dose Most scientists believe that this is a conservative model of the risk Now the risk estimates If you were to take a large population such as 10 000 people and expose them to one rem to their whole body you would
76. ticles can affect the body s cells Inside the body because they give up their energy over a relatively short distance alpha particles can inflict more severe biological damage than other radiations Beta particles fast moving electrons ejected from the nuclei of atoms These particles are much smaller than alpha particles and can penetrate up to 5 64 of an inch of water or human flesh Beta particles are emitted from many radioactive elements They can be stopped by a sheet of aluminum a few millimeters thick Neutrons are particles which are also very penetrating On Earth they mostly come from the splitting or fissioning of certain atoms inside a nuclear reactor Water and concrete are the most commonly used shields against neutron radiation from the core of the nuclear reactor Note It is important to understand that alpha beta gamma and X radiation do not cause the body or any object around the source to become radioactive However most materials in their natural state including body tissue contain measurable amounts of radioactivity Measuring lonizing Radiation HAD and REM human senses cannot detect radiation or discern whether a material 15 radioactive However a variety of instruments can detect and measure radiation reliably and accurately Ludlum Measurements Inc Page 6 5 June 2011 Model 2241 2RK Technical Manual Section 6 Ludlum Measurements Inc The amount of ionizing radiation
77. tion other than natural are regulated by laws passed by Congress Like any other law you have your right to voice views and opinions about it The regulations that control the use of radioactivity in our country are based upon recommendations of science organizations like the International Commission on Radiological Protection the National Council on Radiation Protection NCRP the International Atomic Energy Agency IAEA the United Nations UN and the Health Physics Society HPS Governing bodies like the Environmental Protection Agency EPA the Nuclear Regulatory Commission the Department of Energy DOE and the Food and Drug Administration FDA review these recommendations and propose the regulations that industry and government must follow These are then passed by Congress if found to be acceptable and published in the Code of Federal Regulations CFRs Note The CFR limits the general public to radiation exposure of 100 mrem year with no more than 2 mrem of exposure in any one hour ref 10 CFR 20 1301 Page 6 12 June 2011 Model 2241 2 Section Refer to the Main Board schematic for the following Ludlum Measurements Inc Technical Manual Section 7 Technical Principle of Operation Detector Input Amplifier Negative going detector pulses are coupled from the detector through C021 to Amplifier U021 R024 and 021 protect the input of 0021 from inadvertent shorts
78. to 2500 Vde Page 4 4 June 2011 Section 4 Model 2241 2RK Technical Manual Section 4 VOLUME 8002 a mult turn potentiometer approximately 20 revolutions varies the audible click per event and alarm audio Adjust the control to the maximum clockwise position for maximum volume If the VOLUME control is adjusted to the maximum counterclockwise position the clicks per event or the audible alarm s will not be audible when active Switch Board Controls The switch board utilizes a 16 position rotary switch FUNCTION to select the 16 setup parameters Refer to schematics and component layout drawing near the end of the manual All of the setup parameters stored in the non volatile EEPROM which will retain data even after the Model 2241 2 batteries are removed After the parameters are entered the switch board can be removed and the Model 2241 2 will continue to operate from the previously programmed information Changing parameters and information on switchboard controls are covered in detail in Section 8 of this manual Page 4 5 June 2011 Ludlum Measurements Inc Model 2241 2RK Technical Manual Section 5 Section Safety amp Maintenance Considerations Environmental Conditions for Normal Use Indoor or outdoor use Maximum altitude of 2438 meters 8000 feet above sea level Temperature range of 20 to 50 C 4 to 122 F Maximum relative humidity of less than 95 non condensing Pollution Degree 1
79. to the upper operating range of the detector Confirm that the linearity is within 10 of each respective reading If the readings are off on the lower detector operating region CC If the readings are off at the upper end of the detector operating region adjust DTC Page 8 11 June 2011 Model 2241 2RK Technical Manual Section 8 DETERMINING CC AND DTC This procedure contains the algorithm 0579 method for determining the CC Calibration Constant and the DTC Dead Time Correction An example of the Ludlum Model 44 9 GM detector calibration is used in conjunction with the algorithm calculations to aid in solving the equations Note Ludlum Measurements Inc offers a PC compatible software program that incorporates the read write commands necessary to communicate between a PC and the Model 2241 2 The program also incorporates the algorithm to calculate the detector CC and DTC software is offered in DOS version part number 1370 025 or a WINDOWS version part number 1370 024 Hi Lo Method The hi lo method refers to the placement of the detector in a radiation field using two point CC and calibration to make linear the detector response even in the non linear operating regions of the detector The low radiation field CC should be a field that yields from 2 to 5 count loss The high radiation field DT should be a field that yields from 30 to 60 count loss The algorithm ignores background count
80. up mode for the Model 2241 2 If the board is not installed the normal operation mode counting mode is selected If the switch boatd is installed the selector switch must be set to the 0 position for normal instrument operation The following may be changed using the switch board and are discussed in detail in this section Detector Parameters Current Detector Setup in Use RS 232 Communication Baud Rate RS 232 Detector Parameters Set Read Mode FUNCTION SWITCH POSITION DESCRIPTIONS AND VARIABLES POSITION 0 NORMAL OPERATION places the Model 2241 2 in the normal counting operating mode Unplugging the switch board from the Model 2241 2 main boatd defaults to the normal operating mode POSITION 1 DEAD TIME us allows changing the detector dead time correction for the current detector setup Setting this parameter to 0 disables dead time correction The dead time adjusts from 0 to 9999 microseconds us The incoming counts are adjusted for dead time using the following formula Ludlum Measurements Inc Page 8 2 June 2011 Model 2241 2RK Technical Manual Section 8 m Where 1 n corrected counts per second m incoming count per second 1 system dead time base POSITION 2 CALIBRATION CONSTANT allows changing the calibration P constant for the current detector setup The calibration constant CC rate adjusts from 0 001 to 280 x 10 The calibration constant converts counts
81. ve than the pancake Model 44 9 detector This detector is able to detect low level gamma and X rays in the range of 60 keV 1 25 MeV This detector may be used for measurements up to 50 mR hr The Model 44 2 is used by placing the detector in hand and by slowly moving it from side to side over the area to be measuted Be aware that the very end of the detector opposite the connector is the most sensitive Point the detector towards the radiation being measured Ludlum Measurements Inc Page 2 5 June 2011 Model 2241 2RK Technical Manual Section Instrument Ludlum Measurements Inc Specifications Linearity Readings are within 10 of true value with a detector connected Warm up Time Unit may be used immediately after the LCD initialization sequence is completed approximately five seconds after power up Display a four digit Liquid Crystal Display LCD with digits one half inch in height Two additional 0 51 cm 0 2 in digits used for the overflow counter SCALER mode and exponential powers parameter setup Enunciators are provided for display units ALERT ALARM low battery detector OVERLOAD counting OVERFLOW and scaler COUNTING RATEMETER depending upon how the instrument was calibrated the RATEMETER can display R hr Sv h cpm cps when the control switch is in the RATEMETER position SCALER activated by pushbutton in handle when the three position switch is in the SCALER pos
82. with the backlight OFF Minimum battery voltage is 2 2 0 1 Battery Dependence Meter readings vaty by less than 3 from fully charged batteries until the battery symbol appears indicating the need for recharge or replacement Battery Life typically 200 hours with alkaline batteries display indicates low battery condition Instrument will operate for approximately 24 hours after the battery symbol first appeats Size 16 5 x 89 x 21 6 cm 6 5 x 3 5 x 8 5 Hx W x D Weight 1 6 ke 3 5 kg including batteries Backlight ON Time 5 15 30 60 90 120 180 or 240 seconds for the backlight to stay on when activated by the pushbutton factory set at 5 Set Minimum Display allows lower limit of the auto ranging display to be fixed For example the display can be set to only show values above ot equal to 1 uR hr RS 232 Data Dump Mode enables or disables dump mode to the RS 232 port 1 type connector When enabled the data will be dumped evety two seconds RS 232 Detector Setup Mode allows for input of detector parameters via the RS 232 port Page 3 2 June 2011 Model 2241 2RK Technical Manual Section 3 Model 44 9 Detector Ludlum Measurements Inc Baud Rate selects either 150 300 600 1200 2400 4800 9600 19200 bps Detector Dead Time Compensation DTC adjustable from 0 to 9999 microseconds Calibration Constant adjustable from 0 001 to 280 x 10 counts display unit Display Units
83. y Board Drawing 408 x 259 Display Board Component Layout Drawings 408 x 260 2 sheets Switch Board Drawing 408 x 45 Switch Board Component Layout Drawing 408 X 46 Wiring Diagram Drawing 408 131 Model 44 9 Alpha Beta Gamma Detector Drawing 2 x 206 Energy Response for Ludlum Model 44 9 New Beta Source Efficiencies for Model 44 9 Page 11 1 June 2011 Model 2241 2RK Technical Manual Ludlum Measurements Inc Section 11 Model 44 2 Gamma Scintillator Assembly View Drawing 2 x 205A 1 5 in Tube Socket Board Schematic Drawing 2 x 317 1 5 in Tube Socket Board Component Layout Drawing 2 x 318 Energy Response Curve Model 44 2 Page 11 2 June 2011 LLL Le Tann mun deg 22552 Z ey L Soo 2NI SIN3W3HASVIN SSS 018 Od 807 1998 toog CI VES eR PET r 122 Sono SSU uS QuvOS NIVW Phu vs 8200 229 000 79 MANG tone n INI SINAWAUNSYAW sss OLL Od mS 8 NP KONO UNO ONG y Aot 4008 at AOL 8188 229 5 EN KO AN y 52 9r 221 6404 de Title
84. y to Customer as the original licensee Customer s exclusive remedy and the entire liability of Ludlum and its suppliers under this limited warranty will be at Ludlum or its service center s option repair replacement or refund of the Software if reported or upon request returned to the party supplying the Software to Customer In no event does Ludlum warrant that the Software is error free or that Customer will be able to operate the Software without problems or interruptions This warranty does not apply if the software a has been altered except by Ludlum b has not been installed operated repaired or maintained in accordance with instructions supplied by Ludlum c has been subjected to abnormal physical or electrical stress misuse negligence or accident or d is used in ultrahazardous activities DISCLAIMER EXCEPT AS SPECIFIED IN THIS WARRANTY ALL EXPRESS OR IMPLIED CONDITIONS REPRESENTATIONS AND WARRANTIES INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTY OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE NONINFRINGEMENT OR ARISING FROM A COURSE OF DEALING USAGE OR TRADE PRACTICE ARE HEREBY EXCLUDED TO THE EXTENT ALLOWED BY APPLICABLE LAW IN NO EVENT WILL LUDLUM OR ITS SUPPLIERS BE LIABLE FOR ANY LOST REVENUE PROFIT OR DATA OR FOR SPECIAL INDIRECT CONSEQUENTIAL INCIDENTAL OR PUNITIVE DAMAGES HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY ARISING OUT OF THE USE OF OR INABILITY TO USE THE SOFTWAR

Ludlum 2241-2 RK Radiological Emergency

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