Operators Manual
Contents
1. Biomedical 451B lon Chamber Survey Meter Operators Manual PN FBC 0058 September 2013 Rev 1 2013 Fluke Corporation All rights reserved Specifications are subject to change without notice All product names are trademarks of their respective companies Warranty and Product Support Fluke Biomedical warrants this instrument against defects in materials and workmanship for one full year from the date of original purchase During the warranty period we will repair or at our option replace at no charge a product that proves to be defective provided you return the product shipping prepaid to Fluke Biomedical This warranty does not apply if the product has been damaged by accident or misuse or as the result of service or modification by other than Fluke Biomedical IN NO EVENT SHALL FLUKE BIOMEDICAL BE LIABLE FOR CONSEQUENTIAL DAMAGES Only serialized products and their accessory items those products and items bearing a distinct serial number tag are covered under this one year warranty PHYSICAL DAMAGE CAUSED BY MISUSE OR PHYSICAL ABUSE IS NOT COVERED UNDER THE WARRANTY Items such as cables and nonserialized modules are not covered under this warranty Recalibration of instruments is not covered under the warranty This warranty gives you specific legal rights and you may also have other rights which vary from state to state province to province or country to country This warranty is limited to repairing the instrument2. Figure 1 Fluke 451B lon Chamber Survey Meter lon Chamber Survey Meter Features Features The following sections describe the features of the Survey Meter Overrange Rate If the instantaneous radiation rate measured by the Survey Meter exceeds 50 R h 0 5 Sv h the R in R h or the Sv in Sv h displayed will blink to notify the user that the radiation field exceeds the measuring capability of the Survey Meter Also a potential error in the integrated radiation value may exist due to this condition The blinking will stop when the integrated value is cleared Low Batter Indicator There are about 6 hours of operation remaining when the LOW BATTERY indicator first becomes visible When the LOW BATTERY indicator blinks there is less than 1 hour of operation remaining These times are for two batteries installed and from the first occurrences of these indications If the Survey Meter is turned off during a low battery condition the batteries will recover somewhat but time of operation remaining will be less Audio Alarm The audio alarm set points are set using the RS 232 COMM port connected to a computer along with the associated software The audio alarm set point is set in increments of 1 full scale That is from 1 to 100 of full scale The A command in the menu allows access to the scale and percent set point The alarm will sound when readings reach or exceed the set point Integrate Mode The Integrate Mode allows
3. 1 Check the shipping cartons s and their contents for in shipment damage 2 Check that all items listed on the packing slip are present and in good condition If damage is evident make a claim with the carrier and contact Fluke immediately If items are missing contact Fluke See the How to Contact Fluke section in this manual lon Chamber Survey Meter Operation Operation The following sections describe the operation of the Survey Meter AA Warning To prevent possible electrical shock fire or personal injury do not put metal objects into connectors External Controls There are two external controls on the Survey Meter an ON OFF button and a MODE button ON OFF Button Press the ON OFF button to turn on the product All the elements in the display turn on and the microprocessor runs through an initialization procedure Part of the procedure includes reading the calibration coefficients stored in EEPROM If an EEPROM read error occurs an error code E1 displays at power on and unity calibration coefficients are used The bar graph and digital display will show a reading that decreases as the Survey Meter stabilizes The initial reading usually starts in the 50 R h 50 mSv h range and decreases through the lower ranges to a reading of less than 0 5 mR h 5 uSv h within 40 seconds When the elements in the display turn off with the exception of those necessary for normal operation the user can begin the measurement proc
4. Table 1 Symbols Hazardous voltage Risk of electric Risk of Danger Important E lt See Manual DC DC Direct Curren Current On Off button button Ec product complies with the WEEE Directive 2002 96 EC marking requirements The affixed label indicates that you must not discard this electrical electronic product in domestic household This product contains a Lithium ion battery Do not mix with solid waste stream Spent batteries should be disposed of by a qualified recycler or hazardous materials handler per local regulations Contact your authorized Fluke Service Center for recycling information waste Product Category With reference to the equipment types in the WEEE Directive Annex this product is classed as category 9 Monitoring and Control Instrumentation product Do not dispose of this product as unsorted municipal waste Go to Fluke s website for recycling information Conforms to European Union CE SECH directives AA Warning To prevent possible electrical shock fire or personal injury e Read all safety information before you use the Product e Use the Product only as specified or the protection supplied by the Product can be compromised e Remove the batteries if the Product is not used for an extended period of time or if stored in temperatures above 50 C If the batteries are not removed battery leakage can damage the Product lon Chamber Survey Meter Safety Infor
5. 99 Sv lon Chamber Survey Meter Operation Self Test When the Survey Meter is first turned on it runs through a functional self test procedure During this self test the firmware version of the Survey Meter is displayed along with the HI or LO chamber bias A Warning For safe operation and maintenance of the product note the chamber bias from the self test If chamber bias is LO the Product cannot measure high radiation rates accurately The Product requires service contact Fluke If the Survey Meter passes the self test it goes into the normal operating mode If the Survey Meter fails the self test it remains locked with the firmware revision displayed Contact Fluke for corrective action See the How to Contact Fluke section in this manual Installation The Survey Meter periodically tests for mark signal at its RS 232 port When an RS 232 signal is detected the Survey Meter sends test signals using its sending device and if RS 232 is present and operational the Survey Meter enters into the communications mode The display clears and the letters CO display as an indication that the Survey Meter is in the communications mode The Survey Meter is compatible with a CRT or printing terminal that has a standard RS 232 connector and a 1200 baud rate A computer with a modem or terminal emulator can be used in place of the terminal Set up the terminal or computer for 1200 baud 7 data bits no parity bit and 1 stop
6. a nominal reading of 0 4 mR h 4 uSv h IEC 60529 IP40 IEC 61010 1 Pollution Degree 2 IEC 61326 1 Portable IEC CISPR 11 Group 1 Class A Group 1 ISM equipment group 1 contains all ISM equipment in which there is intentionally generated and or used conductively coupled radio frequency energy which is necessary for the internal functioning of the equipment itself Class A equipment is equipment suitable for use in all establishments other than domestic and those directly connected to a low voltage power supply network which supplies buildings used for domestic purposes Specifications are subject to change without notice Dose equivalent units were determined using conversion coefficients at H 10 found in ICRU 47 April 1992 Side Slide Closed memmen Slide Opened E 5 E o lt 3 D 2 2 3 ES Energy keV hmr02 eps Figure 2 Model 451B DE SI Typical Energy Dependence 451B Operators Manual staan l ei Tree Side Slide Closed Slide Opened 5 E o lt T D 2 2 Effective keV hmr03 eps Figure 3 Model 451B Typical Energy Dependence Receiving Inspection Upon receipt of the Survey Meter
7. digital display is 2 digits followed by a significant zero digit depending on the operating range of the instrument The leading digit is blank or a 1 or a O for clarity Units of measure appear to the right of the digital display Appropriate multipliers also appear on the display units As indicated under Range programmable in R h or Sv h ON OFF button MODE button Ranging and zeroing are fully automatic lon Chamber Survey Meter Specifications Environmental nennen Operating Temperature Range 20 C to 50 C Relative Humidity Range 0 to 95 non condensing Geotropism less than 1 Altitude 2000 m For Indoor use Dimensions L x W x H eee 8 inx 4 in x 8 in 21 6 cm x 11 3 cm x 20 cm Well IN Approximately 2 Ib 9 oz 1 16 kg BatterleS susanne si fm Ea ies Two 9 volt batteries NEDA 1604A or 6LR61 or 6AM6 provide over 200 hours continuous operation Three lithium cells provide chamber bias voltage of 63 V 10 year life expectancy Audio Alarm sssusa oer is Amasa die Set through communication programs Setting at 1 increments 1 to 100 full scale Temperature Sensor A temperature sensor in the 451B DE SI is used to adjust for offset drift due to temperature Readings are not corrected for changes in air density due to pressure and temperature Check Source rr maa sala ahma tam minsaa Model 450UCS item number 3267644 allows user to check for proper instrument operation Gives
8. the LOW BAT message appears The Survey Meter will function on one battery for approximately 100 hours allowing replacement of one battery at a time if the Survey Meter must remain operational during battery changeover Use either regular or alkaline batteries for replacement purposes Batteries are accessible from the rear of the Survey Meter 17 451B Operators Manual Open From Here hms02 eps Figure 5 Battery Access 18 lon Chamber Survey Meter Maintenance Replaceable Parts Information Fluke maintains a complete inventory of all normal replaceable parts To place an order or to obtain information concerning replaceable parts contact Fluke See the How to Contact Fluke section in this manual Table 3 Replaceable Parts List Recalibration and Service Information If your Survey Meter needs recalibration or repair we request that you contact Fluke See the How to Contact Fluke section More information concerning the operation application or service of your Survey Meter can be obtained from the applications engineer at the numbers listed above 19 451B Operators Manual Troubleshooting AA Caution For safe operation and maintenance of the Product use caution when working on this Product If the device indicates a relatively high radiation rate there is a possibility that the Product has been contaminated High rates can guickly cause the operator s cumulative exposure to increase with th
9. the Survey Meter to display the integrated exposure Exposures are accumulated up to 999 R 9 99 Sv Freeze Mode The Freeze Mode will move a bar on the bar graph display to show the user the peak value and will lock on the maximum range The Survey Meter will continue to read and display current readings Auto On Backlight The Survey Meter is equipped with a backlight which automatically turns on when ambient light drops below a predetermined level The backlight will turn off when the ambient light exceeds the predetermined level which is factory set 451B Operators Manual Specifications Radiation Detected A Operating Ranges nnen ACCURACY enge deed Detector STATER NEEN AU dee Warm Up Time Response Time Precisio enei aan Eau EEN EEES Readout E External Controls eneen Automatic Features nnee Alpha above 7 5 MeV beta above 100 keV gamma above 7 keV 451 0 mR h to 5 mR h O mR h to 50 mR h O mR h to 500 mR h O R h to 5 R h O R h to 50 R h 451 DE SI 0 uSv h to 50 uSv h 0 HSv h to 500 uSv h 0 mSv h to 5 mSv h 0 mSv h to 50 mSv h 0 mSv h to 500 mSv h 10 of reading between 10 and 100 of full scale indication on any range exclusive of energy response Calibration source is 137 Cs 349 cc volume air ionization chamber phenolic chamber wall 246 mg cm2 Chamber window is composed of 6 6 mg cm2 Mylar A coating of graphite has been applied to the walls to make them conductive T
10. to Fluke Biomedical s specifications Notices All Rights Reserved Copyright 2013 Fluke Biomedical No part of this publication may be reproduced transmitted transcribed stored in a retrieval system or translated into any language without the written permission of Fluke Biomedical Copyright Release Fluke Biomedical agrees to a limited copyright release that allows you to reproduce manuals and other printed materials for use in service training programs and other technical publications If you would like other reproductions or distributions submit a written request to Fluke Biomedical Unpacking and Inspection Follow standard receiving practices upon receipt of the instrument Check the shipping carton for damage If damage is found stop unpacking the instrument Notify the carrier and ask for an agent to be present while the instrument is unpacked There are no special unpacking instructions but be careful not to damage the instrument when unpacking it Inspect the instrument for physical damage such as bent or broken parts dents or scratches Technical Support For application support or answers to technical questions either email techservices flukebiomedical com or call 1 800 850 4608 or 1 440 248 9300 In Europe email techsupport emea flukebiomedical com or call 31 40 2965314 Claims Our routine method of shipment is via common carrier FOB origin Upon delivery if physical damage is found retain all pac
11. watch the bar graph when the reading is changing quickly and to read the value of a slowly changing or static reading by looking at the digital display The bar graph display is a digital presentation programmed to appear as a linear analog meter display It is also referred to as the analog display throughout this manual Table 2 Bar Graph Display Update Periods 50 R h 500 mSv h 0 05 second 50 mR h 500 uSv h 0 15 second 5 mR h 50 HSv h 0 25 second lon Chamber Survey Meter Theory of Operation There are 20 bars between each major division The numerical values of the five major divisions change appropriately for the range in which the Survey Meter is operating For instance the first major division would have the numeric value of 1 10 or 100 The minor divisions are worth 0 05 0 5 or 5 The incremental nature of both the digital reading and the analog bar graph provide greater accuracy for reading in different portions of the scale For example on the 0 mR h to 5 mR h 0 uSv h to 50 uSv h range with a digital reading of 2 0 and above the analog bar graph can be read more accurately than the digital display Below a digital reading of 2 0 the digital display is more accurate because it consists of three significant digits The stated precision of the digital display is accurate only above a reading of 0 20 on the 0 mR to 5 mR 0 Sv to 50 Sv scale Note The same analysis applies to the all the other ranges becaus
12. a t m asa Saa EKR OAThenamust seit samks MENU ae s hk aisti sien marita i m l s Preventive Maintenance s ssssssessstrnrerretnnrrnrrnnrtnnnrnn rtnn nnnn nren n nena Routine TISSI EE SUOT SO EE SE E EE Replaceable Parts Information nonnen ennen renee vennen Recalibration and Service Information Troubleshooting EE Self Test Failure nonnen aa aa ana naan High Background Readings 20 Geet e CC rennende deed 451B Operators Manual ii List of Tables Table Title Page 1 SETI IS este cto cats ana t d5aS Maata ege danste 2 Bar Graph Display Update Periods nnn nonnen eneen enn ennn 3 Replaceable Parts List iii 451B Operators Manual List of Figures Figure Title Page 1 Fluke 451B lon Chamber Survey Meier 2 Model 451B DE SI Typical Energy Dependence nonnen 3 Model 451B Typical Energy Dependence nnee 4 Location of RS 232 port 5 Battery ACCESS enee Eege ee 451B Operators Manual vi Introduction The Model 451B lon Chamber Survey Meter the Survey Meter is a hand held battery operated meter designed to measure alpha above 7 5 MeV beta above 100 keV and gamma amp x ray radiation above 7 keV using the latest CMOS and LCD technology The Survey Meter case is constructed of high strength ABS plastic A gasket and desiccant pack seal moisture out of the Survey Meter and provides a cushion for the internal components The readout consists of a 2 digit liquid crys
13. bit 1 Connect the 9 pin female connector to an active communication serial port 2 When CO appears on the Survey Meter display press the computer or terminal space bar twice If the Survey Meter displays the CO message but there is no response at the terminal after pressing the space bar twice perform the following tests e Be sure that the Survey Meter and terminal are properly connected via the RS 232 cable If there is still a problem consult Fluke for further instructions See the How to Contact Fluke section in this manual 11 451B Operators Manual Open From Here hms03 eps Figure 4 Location of RS 232 port Operational check Fluke recommends an operational check upon receipt of the Survey Meter and before each use Monitor the start sequence These results indicate the device is operating correctly e There are no error messages in the startup sequence e The display does not freeze showing only the firmware number e The device gets to the background level within 2 minutes 12 lon Chamber Survey Meter Theory of Operation Optional Check Source Use A Warning To prevent personal injury use care in the handling and storage of the check source The check source contains radioactive materials used for the verification of the Product operation For more testing use the check source Model 450UCS Fluke part number 3267644 a radioactive button source that provides a nominal rea
14. damage the circuits The Survey Meter should be kept clean and free from dirt and contamination To clean the Survey Meter wipe with a damp cloth using any commercially available cleaning or decontaminating agent Storage If the Survey Meter is to be stored prior to use pack it in the original container if possible and store in an environment free of corrosive materials fluctuations in temperature and humidity vibration or shock Store the Survey Meter with the two 9 volt batteries removed 16 lon Chamber Survey Meter Maintenance Battery Replacement AA Warning To prevent possible electrical shock fire or personal injury e Batteries contain hazardous chemicals that can cause burns or explode If exposure to chemicals occurs clean with water and get medical aid e Do not disassemble the battery e Repair the Product before use if the battery leaks e Be sure that the battery polarity is correct to prevent battery leakage e Do not short the battery terminals together e Do not disassemble or crush battery cells and battery packs e Do not keep cells or batteries in a container where the terminals can be shorted e Do not put battery cells and battery packs near heat or fire Do not put in sunlight The LOW BAT message will appear on the display approximately 6 hours prior to the Survey Meter becoming inoperable To ensure that the Survey Meter operates to specification change the batteries within 1 hour after
15. der Entry Group at 1 440 498 2560 Repair and calibration To find the nearest service center go to www flukebiomedical com service or In the U S A Cleveland Calibration Lab Tel 1 800 850 4608 x2564 Email globalcal flukebiomedical com Everett Calibration Lab Tel 1 888 99 FLUKE 1 888 993 5853 Email service status fluke com In Europe Middle East and Africa Eindhoven Calibration Lab Tel 31 40 2675300 Email ServiceDesk fluke com In Asia Everett Calibration Lab Tel 425 446 6945 Email service international fluke com To ensure the accuracy of the Product is maintained at a high level Fluke Biomedical recommends the product be calibrated at least once every 12 months Calibration must be done by qualified personnel Contact your local Fluke Biomedical representative for calibration Certification This instrument was thoroughly tested and inspected It was found to meet Fluke Biomedical s manufacturing specifications when it was shipped from the factory Calibration measurements are traceable to the National Institute of Standards and Technology NIST Devices for which there are no NIST calibration standards are measured against in house performance standards using accepted test procedures WARNING Unauthorized user modifications or application beyond the published specifications may result in electrical shock hazards or improper operation Fluke Biomedical will not be responsible for any injuries
16. ding of 0 4 mR h 4 uSv h To check the device do the following 1 Turn on and initialize the Survey Meter 2 After the self test completes wait for 2 minutes 3 Open the beta shield 4 Place the check source flat against the end window 5 Check for a nominal reading of 0 4 mR h 4 uSv h Theory of Operation A Warning To prevent personal injury use care in handling this assembly during removal and installation This Product contains lithium cells with a potential voltage of 63 V on the battery assembly A Caution To prevent damage to the Product do not open or disassemble the Product The high impedance circuits of the ion chamber are easily contaminated with grease and dirt that produce electrical leakage The Survey Meter is an air ionization chamber meter calibrated in exposure rate units of roentgens hour or Sieverts hour for gamma and x ray in the energy range of 20 keV to 2 MeV through the sliding Phenolic shield It can also be used for x ray in the energy range of 7 keV to 30 keV with the sliding shield open The Survey Meter responds to but is not calibrated for beta radiation with the slide open Beta energies that can be measured are above 100 keV The two thin Mylar windows have a combined density thickness of 6 6 mg cm2 The Survey Meter also responds to alpha radiation above 7 5 MeV The liquid crystal display shows the radiation rate in digital and analog form with the range multiplier values also sh
17. e potential for injury Note Install fresh batteries prior to performing any calibration on this product Self Test Failure If the Survey Meter fails self test it remains locked on the firmware revision number See the How to Contact Fluke section High Background Readings The desiccant must be renewed and replaced periodically See the How to Contact Fluke section Erratic Readings Check for broken ion chamber window or loose collector Check for loose chamber bias connector 20
18. e the number of significant digits or active bar elements are independent of the position of the decimal point or the units multiplier There is a small hysteresis built into the range changing circuit so that the Survey Meter does not keep changing scales if the reading is at the threshold of range change It is important when calibrating the Survey Meter that the calibration coefficients track from range to range because an oscillatory condition can occur if the calibration on a given range is low and the coefficient for the next more sensitive range is high In addition to FREEZE the other message that can appear on the display is LOW BAT When the LOW BAT message appears the batteries should be changed within 1 hour The display will indicate HI for good chamber voltage bias condition The program in the Survey Meter ROM is proprietary to Fluke The firmware version appears in the digital part of the LCD display prior to the all elements on display when the Survey Meter is turned on The firmware program consists of three main parts operation communication and monitoring The operation portion of the firmware performs all of the control functions needed to read and control the electrometer and range change amplifier calculate radiation rate and display the calculated values on the LCD Display In addition the measured data are smoothed and displayed in an exponential manner with time that simulates the rise and fall time of a
19. ess Note Background fluctuations may occur less than 0 5 mR h 5 uSv h returning to the original reading typically in less than 3 seconds Mode Button To configure the MODE button to the opposite function without the RS 232 connection use the following procedure 1 Turn off the Survey Meter 2 Press the MODE button 3 Turn on the Survey Meter while continuing to press the MODE button 4 Release the MODE button when the display is in the all elements on condition 5 Use the MODE button to toggle the Survey Meter between the rate mode and the newly selected Freeze or Integrate mode 451B Operators Manual Freeze Mode When configured to select the Freeze mode the MODE button acts as a toggle switch Press the button until FREEZE appears on the display Operation in the Freeze mode gives the user a constant reference of the highest exposure rate obtained from the time the freeze function is initialized The highest reading appears as a single bar on the bar graph The current reading continues to display on the digital display and the bar graph If a measurement is obtained which exceeds the freeze bar reading the freeze bar moves to the higher measurement point The operating range of the Survey Meter remains locked on the highest range attained during the Freeze mode so that the scale and the multiplier remain the same For example assume the scale units appear as 10 20 30 40 50 and the freeze bar is at 47 mR h
20. he collection potential is 63 Volts The Chamber is vented through the desiccant 451B DE SI In order to achieve energy response consistent with measurements of H 10 as reguired by ICR4 47 aluminum has been added to the back wall 38 of the side wall area and to the beta slide With the Beta Shield open the 451B can measure skin dose at H 0 07 and Deep Dose H 10 with the Beta shield closed Less than one minute for initial operation Time measured from 10 to 90 of final value for a step increase decrease in radiation rate such that a range change does not occur 451B 0 mR h to 5 mR h range 8 seconds 0 mR h to 50 mR h range 2 5 seconds 0 mR h to 500 mR h range 2 seconds 0 R h to 5 R h range 2 seconds 0 R h to 50 R h range 2 seconds 451B DE SI 0 uSv h to 50 HSv h range 8 seconds 0 uSv h to 500 uSv h range 2 5 seconds 0 mSv h to 5 mSv h range 2 seconds 0 mSv h to 50 mSv h range 2 seconds 0 mSv h to 500 mSv h range 2 seconds NOTE Instantaneous exposure rate is limited to 50 R h 0 5 Sv h including but not limited to a pulsed field Within 10 of reading Liquid Crystal Display Contains an analog bar graph with a permanent scale on the display and a 2 digit display Analog Display The bar graph consists of 100 segments 2 inches long the scale has five major divisions the appropriate value for the operating range of the instrument will appear below the scale Digital Display The
21. king materials in their original condition and contact the carrier immediately to file a claim If the instrument is delivered in good physical condition but does not operate within specifications or if there are any other problems not caused by shipping damage please contact Fluke Biomedical or your local sales representative Returns and Repairs Return Procedure All items being returned including all warranty claim shipments must be sent freight prepaid to our factory location When you retum an instrument to Fluke Biomedical we recommend using United Parcel Service Federal Express or Air Parcel Post We also recommend that you insure your shipment for its actual replacement cost Fluke Biomedical will not be responsible for lost shipments or instruments that are received in damaged condition due to improper packaging or handling Use the original carton and packaging material for shipment If they are not available we recommend the following guide for repackaging Use a double walled carton of sufficient strength for the weight being shipped Use heavy paper or cardboard to protect all instrument surfaces Use nonabrasive material around all projecting parts Use at least four inches of tightly packed industry approved shock absorbent material around the instrument Returns for partial refund credit Every product returned for refund credit must be accompanied by a Return Material Authorization RMA number obtained from our Or
22. mation The battery door must be closed and locked before you operate the Product Replace the batteries when the low battery indicator shows to prevent incorrect measurements Comply with local and national safety codes Use personal protective equipment Carefully read all instructions Do not touch voltages gt 30 V ac rms 42 V ac peak or 60 V dc Do not use the Product around explosive gas vapor or in damp or wet environments Do not use and disable the Product if it is damaged Do not use the Product if it operates incorrectly Examine the case before you use the Product Look for cracks or missing plastic Use this Product indoors only Remove all accessories before the battery door is opened Each person who uses a product that senses and measures ionizing radiation must o Be approved to do work where there is radiation o Obey all applicable safety procedures and regulations o Be approved to correctly interpret the indications on the product The user of this Product must read and strictly obey the instructions and precautions contained in the manuals If you do not obey the instructions and precautions there is a risk of injury If you do not obey the instructions and precautions there is a risk that the Product will show incorrect indications Before each use do a battery check and other preoperational checks to make sure that the Product operates correctly 451B Operators Manual hmr01 eps
23. n ordinary meter display Range changing is performed automatically If a large increase in signal is detected the range changing skips to higher ranges bypassing exponential rise with time to get to the new reading quickly The Survey Meter continually integrates the detected radiation signal and saves the accumulated amount that may be read by the operator at any time The operator may also reset the integration process 15 451B Operators Manual Maintenance Very little maintenance is required for the Survey Meter but some periodic attention may be necessary especially if the Survey Meter is used in harsh industrial conditions AA Warnings To prevent possible electrical shock fire or personal injury e Do not operate the Product with covers removed or the case open Hazardous voltage exposure is possible e Use only specified replacement parts e Have an approved technician repair the Product e Use care when handling the surface below the High Voltage Board is conductive e Many components on the printed circuit board are static sensitive Obey all ESD precautions when you touch the printed circuit board assembly Preventive Maintenance The desiccant must be renewed and replaced periodically See the How to Contact Fluke section Note Install fresh batteries prior to performing any calibration on the Survey Meter Routine Cleaning Do not immerse the Survey Meter The Survey Meter is not waterproof liquid could
24. on the bar graph If the Survey Meter then measures a radiation field of 120 mR h the scale units will change to 100 200 300 400 500 and the freeze bar appears on the graph at 120 mR h If the Survey Meter measurement goes below 100 mR h the units on the scale will not change until the survey meter is taken out of the Freeze mode However the digital display continues to show the current reading The Survey Meter operates in the Freeze mode until the user toggles the MODE button to return to the normal operating mode Note If a measurement is obtained which causes a range change higher than the alarm set point range the alarm will sound and continue to sound until the Freeze mode is disabled Integrate Mode 10 The Integrate mode is operational 30 seconds after the Survey Meter is turned on and all of the time after that However the integrated exposure can only be displayed when the MODE button has been configured as a toggle to display exposure rate integrated exposure If the MODE button is pressed within the 30 second initialization period of the Survey Meter the display will read 0 When integration starts O uR 0 uSv displays Toggle MODE to read exposure rate as required To reset the integration display toggle the display from the Rate mode to the Integrate mode Keep the MODE button pressed for about 5 seconds The display will clear and then read 0 uR 0 uSv Exposures are accumulated up to 999 R 9
25. owing on the scale It is a lightweight electronic device that requires the computational capabilities of a microprocessor to make it operate It functions in a multiplex mode called quadruplex This mode uses four backplanes to accommodate the 128 elements of the display 13 451B Operators Manual 14 The microprocessor performs data collection averaging and multiplication by stored calibration factors range changing and battery check functions in addition to driving the LCD Between computational periods it sleeps in a low power mode to conserve battery power The microprocessor reads stored information from an electrically erasable memory EEPROM which is used by the program for calibration and display units The EEPROM will retain stored data when the Survey Meter is OFF or when the batteries are removed Data can be entered into the EEPROM using the RS 232 port 63 V collection voltage for the ion chamber is obtained from lithium cells that have a 10 year life All internal power for the Survey Meter is supplied by the 9 V batteries accessible from the rear of the Survey Meter The digital and bar graph displays read directly The bar graph display update periods are listed in Table 2 The digital display updates at 1 second intervals nearest the current bar display update The bar graph and digits display do not always show the same reading because the bar graph is faster than the digital update It is more convenient to
26. sustained due to unauthorized equipment modifications Restrictions and Liabilities Information in this document is subject to change and does not represent a commitment by Fluke Biomedical Changes made to the information in this document will be incorporated in new editions of the publication No responsibility is assumed by Fluke Biomedical for the use or reliability of software or equipment that is not supplied by Fluke Biomedical or by its affiliated dealers Manufacturing Location The 451B lon Chamber Survey Meter is manufactured at Fluke Biomedical 6920 Seaway Blvd Everett WA U S A Table of Contents Title Page Introduction KARI Intended USE nanne enen enen enen ennen enn vens vennen vennen Safety Information muasa caer eebe scenes dannnnabs Deeds k ams TA En MAAT esdek EI EE Ee Ee RE Eeler Low Batter Indicator sneren renee nternet Audio Alarm Integrate EE Freeze Mode nnn oenen vennen ennn eneeens eens vens eens venseensenen Auto Qn Backhght seen eenden Specifications nnee eenen ana a aa aa aa ana a aa n eenen eene enn nennen Receiving Inspection On Operation External Controls annen ene ennen enn eens eenen eens eenseenseenne ON OFF Button Mode Buttons age a a Freeze Mode mummumsa eaa enaa enen eneneeenenen eenen eene enen ennen Integrate EE TN ENEN 11 Je Ute Operational check Optional Check Source Use nnen a a nannat Theory of Operation secs taasen ea t s sana
27. tal display and a 100 segment analog bar graph The bar graph contains a zero segment and twenty groups of five segments each A permanent scale is located on the display screen The major divisions of the scale indicate the units corresponding to the range that the Survey Meter is measuring The units of measurement show next to the 2 digit display LOW BAT and FREEZE appear on the display when the product is operating in these modes External controls consist of an ON OFF button and a MODE button The Survey Meter is auto ranging and auto zeroing The auto on circuit for the backlight is enabled when twilight conditions occur The Survey Meter has an audio alarm that can be set by the user Two 9 volt batteries located in the back of the Survey Meter provide over 200 hours of continuous operation A 440 mg cm2 phenolic shield is provided as a beta shield The shield also serves as an equilibrium thickness for photon measurements amp protects the Mylar window Intended Use The 451B lon Chamber Survey Meter is a hand held battery operated unit designed to measure beta radiation above 100 keV and gamma and x ray radiation above 7 keV 451B Operators Manual Safety Information A Warning identifies conditions and procedures that are dangerous to the user A Caution identifies conditions and procedures that can cause damage to the Product or the equipment under test Table 1 is a list of symbols used on the product and in this manual
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