EXRADIN A101 CT Ion Chamber
Contents
1. EXRADIN A101 CT lon Chamber REF 92680 SeeDOS Product User Manual Standard Ex SI J DOC 80362 00 SeeDOS Product User Manual EXRADIN A101 CT lon Chamber REF 92680 Distributed by SeeDOS Ltd For further information or a quotation please contact Colin Walters at cwalters seedos com General Precautions ee Warnings and Cautions alert users to dangerous conditions 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 damage to the equipment WARNING Electrical shock hazard when connected to 300 V bias supply CAUTION Proper use of this device depends on careful reading of all instructions and labels CAUTION Do not drop mishandle or disassemble unit since it may result in change of calibration factor or damage to thin walled Thimble tip Refer all servicing to qualified individuals CAUTION Do not sharply bend triax cable Damage to the cable may result in high leakage currents Table of Contents eee PAGE General Precautions General Operation Service Notes Parts and Accessories List Customer Responsibility Features and Specifications Warranty PONMAOWD 7601 MURPHY DRIVE x MIDDLETON W1 53562 e x WW n General Operation All Exradin chambers are attached to a 1 5 m length of low noise flexible triaxial cable that is terminated by a triaxial or coaxial connecto2. 72157 LEMO Connector in place of Triax BNC Plug M F 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 accompanying 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 Canada restricts the sale distribution or use of this device to by or on the order of a licensed medical practitioner The use of this device should be restricted to the supervision of a qualified medical physicist Should repair or replacement of this device become necessary after the warranty period the customer should seek advice from Standard Imaging Inc prior to such repair or replacement If this device 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 chamber may need to be calibrated The owner of this device 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
3. most evident in the rate current mode General Operation AAA The CT chamber is designed to measure CT slices These may be summed or integrated as is the standard practice for CT Meausements Thus the MSAD multiple scan average dose can be determined as is usual For this reason the response is flat within the length of the chamber Figure 1 shows the flat response of the chamber it is flat to within 3 over the central 10 cm of its length 08 4 0 6 al 0 4 e 4 02 E reading normalized to central value ool 00 ee 10 8 6 4 2 0 2 4 6 8 10 Stem End Distal End position on chamber cm Figure 1 Flatness of the CT chamber Operating Instructions 1 With nothing connected to the input jack of the electrometer 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 stated 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 al
4. the axial length of the collecting volume The two outer most grooves represent the termination of the collecting volume each 5 cm away from the central groove Within these two outer most grooves is the collecting volume that is rated with a flatness response of 3 and is 10 0 cm in length Adapter Sleeve The Adapter Sleeve for the CT Chamber is constructed of acrylic PMMA The Adapter Sleeve has an outer diameter of 12 7mm which will fit into most commercially available CT Phantoms Simply slide the Sleeve over the CT Chamber until the Sleeve bottoms are on the shoulder of the CT Chamber and insert the CT Chamber with sleeve into the CT Phantom Venting The CT Chamber vents to the ambient via 2 holes located on the cylindrical body of the chamber proper When the acrylic Adapter Sleeve is in position on the chamber body there is adequate clearance for the chamber to vent Underwater Operation This chamber is not waterproof This type of chamber is typically not used in water 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 warranty will become void and the calibration factor will change Under normal use the chambers should provide years of trouble free service Parts and Accessories _ ee REF Description 72170 A101 Acrylic Adapter Sleeve 1 3 mm PMMA
5. any form or by any means without prior written consent of Standard Imaging Inc Features and Specifications EEE Collecting Volume Collecting Volume Length Collector Diameter Body Tube Outside Diameter Wall Thickness Chamber Length Body Tube and Guard Material Response Uniformity over the central 10 cm of chamber length Energy Response 80 to 150kVp Collector Material Electrical Power Require ments Nominal Collection Efficiency Maximum Polarizing Potential Nominal Inherent Leakage Currents Low Noise Triaxial Cable Connector Included Adapter Sleeve Operating Parameters Humidity Temperature Pressure Storage Parameters Humidity Temperature Pressure 4 6 cc 10 0cm 2 4 mm 10 0 mm 1 0 mm 164 3 mm Shonka air equivalent C552 plastic 3 4 Carbon Fiber Operates at 300 VDC 100 1000 V 105A 1 5 m long 50 ohms 29 pf ft Triaxial BNC Plug 2 Lug Male and protective cap connected by chain standard others available upon request Wall Thickness of 1 3 mm Constructed of PMMA 20 to 80 non condensing 10 to 40 C 680 to 770 mm Hg 0 to 95 non condensing 15 to 50 C 600 to 800 mm Hg Notes Notes Notes 11 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 o
6. g Inc shall not be otherwise liable for any damages including but not limited to incidental damages consequen tial damages or special damages Repaired or replaced products are warranted 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 fitness 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 damages 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 for any warranty conditions unique to the product Distributed by SeeDOS Ltd Please contact cwalters seedos com
7. low the user to zero the device at any time If desired perform this system zeroing now General Operation e TF z 7 Check the system leakage Take a reading without exposing 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 9 Insert the CT chamber and take at least 3 measure ments 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 calibra tion factor consists of the electrometer calibration and the ionization chamber calibration factor 11 When all measurements are completed set bias voltage to 0 VDC turn off the electrometer and discon nect the ionization chamber Service Notes eee External Marks The Exradin A101 CT Chamber is provided with 3 external groove marks on the chamber body signifying important locations of the collecting volume The middle groove represents the center of
8. r 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 connector contact of triaxial connectors and the connector body of coaxial connectors The shell 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 shell and the guard Either polarity may be applied to the shell and either the shell or guard may be grounded Safety and other considerations recommend grounding the shell which then requires an electrometer with a floating input All Exradin chambers can support 1000 V between shell and guard However depending on the particular circumstance and radiation intensity as little as 90 V may yield essentially 100 charge collection Because Exradin ionization chambers do not exhibit voltage soakage phenomena readings of ionization current may be made immediately after application of the polarizing potential However it is good practice to pause a minute or two after changing the potential to allow switching transients induced in the electrometer to completely subside Such transients are
9. r as a new product from an authorized dealer or distributor of Standard Imaging Inc For a period of twenty four 24 months for ionization chambers and twelve 12 months for all other Standard Imaging Inc products from the date of original delivery to the purchaser or a distributor this product is warranted against functional defects in 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 dissembled altered or repaired other than by Standard Imaging Inc or if the product has been subject to abuse misuse negligence or accident Standard Imaging s sole and exclusive obligation and the purchaser s sole and exclusive remedy under the above warranties are limited to repairing or replacing free of charge at Standard Imaging s option 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 12 or 24 month warranty period 3 which are returned to Standard Imaging promptly after discovery of the defect and 4 which are found to be defective upon Standard Imaging s examination Transportation charges are the buyer s responsibility This warranty extends to every part of the product except fuses batteries or glass breakage Standard Imagin
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