LUDLUM ION CHAMBER
MODEL 9-4 USERS MANUAL
June 2018
Serial Number 265751 and Succeeding
Serial Numbers
Page 1: ...LUDLUM ION CHAMBER MODEL 9 4 USERS MANUAL June 2018 Serial Number 265751 and Succeeding Serial Numbers ...
Page 2: ...LUDLUM ION CHAMBER MODEL 9 4 USERS MANUAL June 2018 Serial Number 265751 and Succeeding Serial Numbers ...
Page 3: ...Ludlum Measurements Inc Copyright 2013 ...
Page 4: ... any implied warranty of merchantability or fitness which extend beyond the description of the face there of If the product does not perform as warranted herein purchaser s sole remedy shall be repair or replacement at the option of Ludlum Measurements In no event will Ludlum Measurements be liable for damages lost revenue lost wages or any other incidental or consequential damages arising from th...
Page 5: ... the information provided as failure to do so may result in damage to the instrument or instrument failure GENERAL SAFETY PRECAUTIONS The following general safety precautions apply to the operator of the instrument during all phases of operation These precautions should be followed or else the instrument may no longer provide the necessary protection for which the instrument was intended DO NOT RE...
Page 6: ...y cause burns or irritation to the skin ELECTRICAL SHOCK unless the necessary precautions are taken this is an indication that physical contact with the internal components of the instrument may result in electrical shock HOT AREA this is an indication that the component or components may be hot resulting in burns to the skin POISON this is an indication that the contents may be hazardous to your ...
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Page 8: ...bration 11 Storage 12 Desiccant 12 SPECIFICATIONS 14 RECYCLING 17 PARTS LIST 18 MAIN CIRCUIT BOARD DRAWING 293 X 711 19 ELECTROMETER BOARD DRAWING 293 X 670 22 DRAWINGS 23 TABLE OF FIGURES Figure 1 Battery Installation and Removal 4 Figure 2 Battery Door Internal Markings 5 Figure 3 Main Board Layout Front Back of manual Figure 4 Main Board Layout Back Back of manual Figure 5 Main Board Schematic ...
Page 9: ... done digitally using a special calibration kit part number 4293 676 available from Ludlum Measurements This kit includes a special instrument can pressure calibration kit all necessary cables and control software The Model 9 4 calibration kit allows the ability to calibrate for temperature and pressure Temperature and pressure compensation thus allows the instrument to measure within 20 of the tr...
Page 10: ...splay lights located in the meter compartment ZERO ADJUST This is a full one turn control that allows for compensation of electrometer drift Press and hold the RESET button for five seconds then adjust for a zero reading RESET Button The RESET circuit grounds the chamber and opens the chamber connection to the electrometer This action causes a hard upscale transient on the 1 and 10 scales Hold the...
Page 11: ... be downloaded from the Ludlum website at www ludlums com Find the form by clicking the Support tab and selecting Repair and Calibration from the drop down menu Then choose the appropriate Repair and Calibration division where you will find a link to the form Instrument Configuration The Model 9 4 has two options for chamber wall voltage An internal jumper may be selected to maintain voltage on th...
Page 12: ... zero with the instrument OFF however a settling time of 15 minutes is required for the 1 scale to settle within 0 1 mR hr Battery Installation Ensure the Model 9 4 range selector switch is in the OFF position Open the battery lid by pushing down and turning the quarter turn thumbscrew counterclockwise a quarter of a turn Install two D size batteries in the compartment Figure 1 Battery Installatio...
Page 13: ...n This is accomplished simply by pressing the BAT TEST button Ensure that the meter needle deflects to the battery test portion of the meter scale If the meter does not respond check to see if the batteries have been correctly installed Replace the batteries if necessary Operational Check To assure proper operation of the instrument between calibrations and periods of non use the following instrum...
Page 14: ...ranges display a countdown from five to zero when the RESET is pressed and also when it is released On these two lower ranges the user should hold the RESET down for five seconds to allow the transient to decay Expose the instrument to a check source Observe that the meter reading increases as the check source gets closer to the instrument The depressions on the side of the instrument housing indi...
Page 15: ...he can One layer of 3 5 mg cm aluminized metallized polyester covers the ion chamber resulting in a window thickness of 7 mg cm with the beta slide open and a 1000 mg cm2 window with the beta slide closed Electrometer The electrometer consists of U1 R2 and supporting components On the 1 scale RL1 and RL2 are open With conduction in the chamber to the negative wall pin 8 of U1 goes slightly negativ...
Page 16: ...or input bias current compensation Offset Adjustment The electrometer op amp will have some offset voltage Internal calibration control R111 will provide an offset voltage that can be adjusted to null out the electrometer offset voltage Place instrument in a field less than 0 1 mR hr then select the 100 scale and adjust R111 for zero meter reading Zero Adjust The primary function of the zero adjus...
Page 17: ...1 U100 is approximately 2 volts at full scale Higher scales follow the same scheme through the analog switches selected by the range switch The output voltage of U100 is connected to microprocessor U110 which allows calibration temperature correction and altitude compensation The signal reference voltage is 0 2 volts at the output of DA converter U112 allowing a below zero meter reading when adjus...
Page 18: ... jumper is placed between pins 1 and 2 of JP100 If the operator chooses to have wall voltage off with the instrument switched off then the jumper should be moved to pins 2 and 3 of JP100 U105 and associated components generate 5 volts for the main board circuits U106 provides regulated 2 5 volt reference VR100 provides 4 85 volts for the electrometer U107 and associated components provides 1 5 vol...
Page 19: ...the instrument OFF and remove the batteries 2 Allow the instrument to sit for one minute before cleaning the exterior or accessing any internal components for maintenance Accessing internal components for maintenance increases the risk of electrical shock if these steps are not followed Maintenance RECALIBRATION Recalibration should be accomplished after maintenance or adjustments have been perfor...
Page 20: ... in corrosion on the battery contacts DESICCANT Remove the instrument can and observe the translucent plastic desiccant box If the desiccant is blue close the can and use the instrument If the desiccant is pink replace with a fresh box The restraining strap may be loosened by pressing the center tab toward the strap The silica used in the desiccant box may cause irritation to the skin if handled d...
Page 21: ...hen removed from the microwave or oven Please use caution so as to avoid burning your skin If the instrument is stored in an area with high humidity rapid changes in temperature should be avoided A storage cabinet with a light bulb inside is one means of keeping the instrument in a slightly warmer than ambient temperature environment in order to prevent problems from rapid changes in temperature a...
Page 22: ...pen 50 mR hr Reading with slide closed 1 2 mR hr Thus Beta Factor 234 divided by 50 minus 1 2 4 8 Energy Response within 20 of true value from 40 keV to 2 MeV Magnetic Field Exposure per ANSI 42 17A magnetic fields of 800 A m cause less than a 15 deviation in instrument response Multipliers 1 10 100 1K and 10K selected by a front panel range selector switch Transient meter movement will occur when...
Page 23: ...ansient to decay Zero Adjust a control allowing limited background subtract and also used to compensate electrometer drift Battery Check Batteries are good if the meter needle is above the BAT OK mark when the BAT TEST pushbutton is pressed At 2 1 Vdc the meter needle will drop to the edge of the BAT OK area when the BAT TEST pushbutton is pressed Battery Dependence Instrument calibration change i...
Page 24: ...t becomes conductive occurs This is found in industrial environments or construction sites considered harsh environments Power two D cell batteries housed in a sealed externally accessible compartment Temperature Range 20 to 50 C 4 to 122 F temperature compensation maintains calibration within 20 of 22 C 72 F reading over the entire temperature range Weight 1 9 kg 4 2 lb including batteries ...
Page 25: ...y 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 The following types of recyclable materials are present in Ludlum Measurements Inc electronic products and should be recycled separately The list is not all inclusive nor does it suggest that all materials are present in each ...
Page 26: ...igure 2 1 x2 Duracell D Cell 21 9313 Alkaline Batteries Handle 7363 139 Portable Grip 6 32 x 3 8 Flat Button 17 8519 Head Stainless Steel Screws 6 Stainless Steel Internal 20 9009 Tooth Lock Washer Model 9 4 Chamber Top 7536 223 Co Netic Shield Model 9 4 Chamber Top 7536 224 Netic Shield Model 9 4 Model 9 4 User s Manual Certificate of Calibration FORM C22A Valid for 1 Year Section 8 Model 9 4 Ion...
Page 27: ...C108 0 001uF 100V 04 5659 C109 68uF 10V 04 5654 C110 0 1uF 100V 04 5792 C111 1uF 50V 04 5708 C112 0 001uF 100V 04 5659 C113 C116 0 01uF 200V 04 5765 C118 C119 0 01uF 200V 04 5765 C120 0 47uF 100V 04 5776 C121 C122 0 01uF 200V 04 5765 C123 68uF 10V 04 5654 C124 C125 0 1uF 100V 04 5792 C126 0 01uF 200V 04 5725 C127 0 1uF 100V 04 5792 C128 1uF 16V 04 5701 C129 0 01uF 50V 04 5664 C130 0 47uF 100V 04 5...
Page 28: ...CMPD2005S 07 6468 CR106 CMPSH 3 TR 07 6489 CR107 CMPD3003S 07 6515 R100 100K 250mW 1 12 7834 R101 365K 250mW 1 12 7049 R102 61 9K 250mW 1 12 7026 R103 1M 250mW 1 12 7844 R104 22 1Ohm 250mW 1 12 7055 R105 100K 250mW 1 12 7834 R106 365K 250mW 1 12 7049 R107 15K 250mW 1 12 7998 R108 47 5K 250mW 1 12 7872 R109 27K 250mW 1 12 7243 R111 100K 3266X1 104 09 6823 R112 154K 250mW 1 12 7197 R113 221Ohm 250mW...
Page 29: ... 12 7832 R151 221K 250mW 1 12 7845 R152 R153 1M 250mW 1 12 7844 R154 100Ohm 250mW 1 12 7840 R155 1M 250mW 1 12 7844 R156 100Ohm 250mW 1 12 7840 R157 1K 250mW 1 12 7832 R158 47 5K 250mW 1 12 7872 R159 100K 3266X1 104 09 6823 R160 124K 250mW 1 12 7032 R161 1MK 250mW 1 12 7844 R162 10K 250mW 1 12 7839 R163 301Ohm 250mW 1 12 7863 P100 1 640456 0 MTA100 10 13 8066 P101 640456 3 MTA100 3 13 8081 P102 53...
Page 30: ...7844 R2 500G 330mW 20 12 7248 R3 4 2G 1W 10 12 8022 R6 27K 1 4W 1 12 7243 R7 500G 330mW 20 12 7248 R8 1M 1 4W 1 12 7844 R9 27K 1 4W 1 12 7243 RL1 Bobbin Assembly 4293 541 SPST NC MDSR 7 Reed Assy 7293 532 RL2 Bobbin Assembly 4293 538 SPDT MDRR DT Reed Assy 7293 543 P1 1 640456 0 MTA100 10 13 8066 P2 103186 1 13 847 Electrometer Board Drawing 293 670 CAPACITORS INTEGRATED CIRCUIT DIODES RESISTORS R...
Page 31: ...ual Section9 Ludlum Measurements Inc Page 23 June 2018 Drawings MAIN BOARD SCHEMATIC Drawing 293 711 4 Sheets MAIN BOARD LAYOUT 293 712 2 Sheets ELECTROMETER BOARD Drawing 293 670 ELECTROMETER BOARD LAYOUT 293 672 Section 9 ...
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