Parallel Plate Ionization Chambers
Contents
1. EXC y Parallel Plate lonization Chambers User Manual G www Standard Imaging com EXC iy Parallel Plate lonization Chambers STANDARD IMAGING INC TEL 800 261 4446 7601 Murphy Drive TEL 608 831 0025 Middleton WI 53562 2532 FAX 608 831 2202 Feb 2005 2005 Standard Imaging Inc DOC 80332 06 General Precautions Warnings and Cautions alert users to dangerous con ditions that can occur if instructions in the manual are not obeyed Warnings are conditions that can cause injury to the operator while Cautions can cause dam age to the equipment WARNING Electrical shock hazard when connected to 300V bias supply WARNING Exradin lon Chambers are intended for quality assurance and calibration measurements They are not intended to be connected to a patient for real time dosimetry measurements T CAUTION Proper use of this device depends on careful reading of all instructions and labels CAUTION A Do not drop mishandle or disassemble unit since it may result in change of calibration fac tor or damage Refer all servicing to qualified individuals CAUTION Do not sharply bend triaxial cable Damage to the cable may result in high leakage currents This manual applies to the following parallel plate chamber models Model REF A10 92702 A11 92701 P11 92703 T11 92704 A11TW 92708 P11TW 92709 T11TW 92710 Table of Contents General Precautions General Operat2. GUARD 9 28 6 4 FOR VENTING STEM ve 17 4 COLLECTOR ALL DIMS ARE APPROX AND IN MM SIDE VIEW Collecting Volume Nominal Calibration Factor Centroid of Collecting Volume Collector Diameter Window Collector Gap Window Window Support Rings Collec tor and Guard Material Included Waterproofing Cap 0 92 cm 3 4 R nC 1 5 mm from top of window 20 0 mm 3 0 mm Kapton film 3 86 mg cm A11TW Shonka Air Equiv plastic C552 P11TW Polystyrene Equiv plastic D400 T11TW Shonka Tissue Equiv plastic A150 Wall thickness of 1 0 mm constructed of acrylic TG 51 compliant 10 Service Notes Stem The one piece polycarbonate stem 0 9 cm OD 7 6 cm long found on these chambers is an integral part of the chamber assembly and is not to be removed under any circumstances Venting These particular ionization chambers are equipped with a Tygon tube secured to the chamber stem and running the full length of the triaxial cable The triaxial cable is inside the tubing The tubing is sealed to the chamber stem and is open to ambient conditions at the connector end This tubing is not intended to be removed or altered by the customer and doing so will void the warranty Calibration Cap Calibration caps constructed of the same material as the major elements of the chamber are available to provide more than adequate build up for Cobalt 60 radiation To secure
3. product except consumables fuses batteries or glass breakage Standard Imaging Inc shall not be otherwise liable for any damages including but not limited to incidental damages consequential damages or special damages Repaired or replaced products are war ranted for the balance of the original warranty period or at least 90 days This warranty is in lieu of all other warranties express or implied whether statutory or otherwise including any implied warranty of fit ness for a particular purpose In no event shall Standard Imaging Inc be liable for any incidental or consequential damages resulting from the use misuse or abuse of the product or caused by any defect failure or malfunction of the product whether a claim of such dam ages is based upon the warranty contract negligence or otherwise This warranty represents the current standard warranty of Standard Imaging Inc Please refer to the labeling or instruction manual of your Standard Imaging Inc product or the Standard Imaging Inc web page for any warranty conditions unique to the product 14 Sel
4. Imaging Heat Software Products y All Other Standard ear Imaging Products y Standard Imaging Custom Product 90 days Consumables 90 days Serviced Product 90 days Resale Products As defined by the Original Equipment Manu facturer ADCL Product CalibrationADCL Product Calibration Standard Imaging uses the UW ADCL for recalibrations required under war ranty 0 90 days 100 of ADCL Calibration Costs 91 182 days 75 of ADCL Calibration Costs 183 365 days 50 of ADCL Calibration Costs 366 639 days 25 of ADCL Calibration Costs days from date of shipment to customer Standard Imaging s sole and exclusive obligation and the purchaser s sole and exclusive remedy under the above warranties are at Standard Imag ing s option limited to repairing replacing free of charge or revising labeling and manual content on a product 1 which contains a defect covered by the above warranties 2 which are reported to Standard Imaging Inc not later than seven 7 days after the expiration date of the warranty period in the table 3 which are returned to Standard Imaging Inc promptly after discovery of the defect and 4 which are found to be defective upon exami nation by Standard Imaging Inc Transportation related charges including but not limited to shipping customs tariffs taxes and brokerage fees to Standard Imaging are the buyer s responsibility This warranty extends to every part of the
5. cap on chamber Simply place cap over chamber window In the event of a Model 11TW Calibration Waterproof Cap follow instructions found under Waterproofing Cap for Model 11TW Waterproofing Cap A10 AND 11TW ONLY The waterproofing cap provided with the chamber is made of acrylic and has a 1 0 mm thick window as recommended by the AAPM TG 51 protocol The O Ring inside the cap is designed to offer a snug fit to the chamber s outer diameter to ensure its seal To secure cap on chamber press cap firmly down onto chamber until it bottoms on chamber window ring Oc casionally the O Ring inside the cap will become twisted and prevent complete bottoming If this occurs simply rotate the cap either clockwise or counterclockwise while continuing downward pressure until it bottoms on chamber window ring To remove cap from chamber Gently rotate either clockwise or counterclockwise cap while pulling slightly upward Kapton Window A10 AND 11TW The window is made of thin conducting Kapton film and is under tension Touching anything to the window is to be avoided Tygon is a trademark of Saint Gobain Performance Plastics Kapton is a trademark of E I du Pont Nemours and Company 11 Service Notes Continued Service and Maintenance There are no user serviceable parts within these ionization chambers Under no circumstance should the user attempt to repair or disassemble the chamber and or connector as the warrant
6. g 1 Designed to Meet 8 Model A10 Planar Electron Chamber A10 REF 92702 TYGON TUBING FOR VENTING STEM WINDOW 0 30 0 GUARD 914 2 14 0 COLLECTOR ALL DIMS ARE APPROX AND INMM SIDE VIEW Collecting Volume 0 051 cm Nominal Calibration Factor 60 R nC Centroid of Collecting Volume Collector Diameter Window Collector Gap Window Window Support Rings Collec tor and Guard Material Included Waterproofing Cap Polarity 1 0 mm from top of window 5 4 mm 2 0 mm Kapton film 3 86 mg cm A10 Shonka Air Equiv plastic C552 Wall thickness of 1 0 mm constructed of acrylic TG 51 compliant lt 1 Model 11 Spokas Chamber A11 REF 92701 P11 REF 92703 T11 REF 92704 TYGON TUBING FOR VENTING WINDOW 044 5 4 GUARD h 9 28 6 ZZZZZZZZZT STEM COLLECTOR ALL DIMS ARE APPROX AND IN MM SIDE VIEW Collecting Volume Nominal Calibration Factor Centroid of Collecting Volume Collector Diameter Window Collector Gap Window 0 62 cm 5 5 R nC 2 0 mm from top of window 20 0 mm 2 0 mm 1 0 mm Window Support Rings Collec A11 Shonka Air Equiv tor and Guard Material plastic C552 P11 Polystyrene Equiv plastic D400 T11 Shonka Tissue Equiv plastic A150 9 Model 11 TW Thin Window Chamber A11TW REF 92708 P11TW REF 92709 T11TW REF 92710 e TYGONO TUBING 5 WINDOW 0 44 5
7. ion Calibration Parts and Accessories General Chamber Specifications Model A10 Planar Electron Chamber Model 11 Spokas Chamber 10 Model 11TW Thin Window Chamber 11 Service Notes 12 Service Policy 13 Customer Responsibility 14 Warranty 0 LOIRE m ul 7601 MURPHY DRIVE MIDDLETON WI 53562 2532 USA WWW STANDARDIMAGING COM Standard Imaging E XEU Wi il N General Operation All Exradin parallel plate chambers are attached to a 1 5 m length of low noise flexible triaxial cable that is termi nated by a triaxial or coaxial connector The collector of the chamber is common with the center wire of the cable and the center contact of the connector The guard is common with the inner cable braid and the middle con nector contact in the case of triaxial connectors and the connector body in the case of coaxial connectors The window outer electrode usually ground is common with the outer braid of the cable and the connector body in the case of triaxial connectors and the pigtail extending out the rear of coaxial connectors The design of Exradin chambers requires that the collector and guard operate at essentially the same potential The polarizing potential supplied by an electrometer is applied between the window and the guard as shown in Figure 1 Either polarity may be applied to the window and either the window or guard may be grounded Safety and other considerations recommend grounding the window which then requ
8. ires an electrometer with a floating input All Exradin chambers can support 1000 V between window and guard However depending on the particular circum stance and radiation intensity as little as 90 V may yield essentially 100 charge collection General Operation Continued WINDOW COLLECTOR a A m w 2 GUARD O Z 9 O J 7 ELECTROMETER Figure 1 Parallel Plate Chamber and Electrometer Because Exradin ionization chambers do not exhibit volt age soakage phenomena readings of ionization current may be made immediately after application of the polar izing potential However it is good practice to pause a minute or two after changing the potential to allow switch ing transients induced in the electrometer to completely subside Such transients are most evident in the rate current mode Operating Instructions 1 With nothing connected to the input jack of the elec trometer turn the power on and wait at least 15 minutes for warm up 2 Verify the leakage of the electrometer is within the manufacturer s stated acceptable limits 3 Connect the ionization chamber to the electrometer and apply 100 voltage bias 4 Allow the electrometer and ionization chamber system at least 10 minutes to stabilize making certain that all cabling is lying flat and unkinked 5 Verify the leakage of the ionization chamber is within the manufacturer s sta
9. need to be calibrated The owner of this product has sole responsibility for any malfunction resulting from abuse improper use or maintenance or repair by anyone other than Standard Imaging Inc The information in this manual is subject to change without notice No part of this manual may be copied or reproduced in any form or by any means without prior written consent of Standard Imaging Inc 13 Warranty Standard Imaging Inc sells this product under the warranty herein set forth The warranty is extended only to the buyer purchasing the product directly from Standard Imaging Inc or as a new product from an authorized dealer or distributor of Standard Imaging Inc For a period provided in the table below from the date of original delivery to the purchaser or a distributor this Standard Imaging Inc product provided in the table is warranted against functional defects in design materials and workmanship provided it is properly operated under conditions of normal use and that repairs and replacements are made in accordance herewith The foregoing warranty shall not apply if the product has been altered disassembled or repaired other than by Standard Imaging Inc or if the product has been subject to abuse misuse negligence or accident Product Warranty Period Standard Imaging lonization Chambers year Standard Imaging Well Chambers 2years Standard Imaging Electrometers 2years Standard
10. practice for other ionization chambers it is recommended that Exradin chambers be calibrated every 2 years This calibration should be performed by an Accredited Dosimetry Calibration Laboratory ADCL Standard Imaging offers calibrations from the University of Wisconsin ADCL You need only one purchase order to cover calibrations shipping and handling and service Standard Imaging hand carries all instruments to and from the University of Wisconsin ADCL Parts and Accessories REF 72136 72137 72130 72131 72132 72133 72134 72135 General Description A10 Waterproof cap 1 0 mm acrylic Model 11 Waterproof cap 1 0 mm acrylic A11 Co 60 Calibration Cap 1 8 mm P11 Co 60 Calibration Cap 3 2 mm T11 Co 60 Calibration Cap 3 4 mm A11TW Co 60 Calibration Waterproof Cap 2 8 mm P11TW Co 60 Calibration Waterproof Cap 4 2 mm T11TW Co 60 Calibration Waterproof Cap 4 4 mm Chamber Specifications Nominal Collection Efficiency 100 Maximum Polarizing Potential 1000 V Nominal Inherent Leakage Currents 10 A Low Noise Triaxial Cable 50 ohms 29 pF ft 1 5 m long Signal Connector Triaxial BNC Plug 2 Lug Male unless requested as other High Voltage Connector Integral with triaxial connector shell of chamber is common with connector body Humidity 10 80 non condensing Temperature 15 50 C Pressure 680 770 mm Hg Product Standards IEC 60601 1 IEC 60731 ga
11. red service is cost prohibitive Products incurring service charges may be held for payment Standard Imaging does not provide loaner products See the Standard Imaging Warranty and Customer Responsibility for additional information 12 Customer Responsibility This product and its components will perform properly and reliably only when operated and maintained in accordance with the instructions contained in this manual and accom panying labels A defective device should not be used Parts which may be broken or missing or are clearly worn distorted or contaminated should be replaced immediately with genuine replacement parts manufactured by or made available from Standard Imaging Inc CAUTION Federal law in the U S A and Ca nadian law restrict the sale distribution or use of this product to by or on the order of a licensed medical practitioner The use of this product should be restricted to the supervision of a qualified medical physicist Measurement of high activity radioactive sources is potentially hazardous and should be performed by quali fied personnel Should repair or replacement of this product become necessary after the warranty period the customer should seek advice from Standard Imaging Inc prior to such re pair or replacement If this product is in need of repair it should not be used until all repairs have been made and the product is functioning properly and ready for use After repair the product may
12. ted acceptable limits If measured in the presence of background sources note that this signal will add to the leakage of the chamber 6 Some electrometers such as the Standard Imaging MAX 4000 Electrometer allow the user to zero the device at any time If desired perform this system zeroing now 7 Check the system leakage Take a reading without ex posing the chamber to radiation This reading should be less than 0 1 of the final signal expected If it is not the leakage should be subtracted from the signal 8 Measure atmospheric temperature and pressure For well chambers measure the temperature in the well of the chamber General Operation Continued 9 Insert the ion chamber and take at least 3 measurements Generally the measurements should not be moving in only one direction i e three readings that continue to drop and hence may not yet be stabilized If a current measurement is done allow sufficient time for value to stabilize 10 Analyze the data taking into account the average of the readings system leakage temperature pressure corrections calibration factors and any other appropriate corrections to be made Keep in mind that the calibration factor consists of the electrometer calibration and the ion ization chamber calibration factor 11 When all measurements are completed set bias volt age to 0 VDC turn off the electrometer and disconnect the ionization chamber Calibration As is standard
13. y will become void and the calibration factor will change Under normal use the chambers should provide years of trouble free service If assistance is desired in the proper disposal of this product including accessories and components after its useful life please return to Standard Imaging Service Policy If service including recalibration is required please con tact Standard Imaging s Customer Service department by phone or email prior to shipping the product Standard Imaging s Customer Service and Technical Service staff will attempt to address the product issue via phone or email If unable to address the issue a return material authoriza tion RMA number will be issued With the RMA number the product can be returned to Standard Imaging It is the responsibility of the customer to properly package insure and ship the product with the RMA number clearly identi fied on the outside of the package The customer must immediately file a claim with their carrier for any shipping damage or lost shipments Return shipping and insurance is to be pre paid or billed to the customer and the customer may request a specific shipper Items found to be out of warranty are subject to a minimum service fee of 1 hour labor excluding recalibrations for diagnostic efforts and require a purchase order PO before service is performed With concurrence from customer the product may be re placed if it is unserviceable or if the requi
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