VS472 User`s Manual - VS472 Radon Sniffers
Contents
1. when in one of the Sniff modes While in Timer or Pump modes this button will also briefly toggle the display to show either the pre set time that the user has just entered or the time remaining for the count or pump Pump Button Used to run the internal pump only Timer Button Used to enter a time for which the VS472 will count On Off Button Used to turn the VS472 on and off NOTE This button must be held for two seconds in order to turn the power off Threaded Holes for Retainer Bracket or Light Tight Cap Thisis where the screws to hold a retainer bracket or a light tight cap in place are inserted 1 4 Display Overview When in one of the Sniff modes the main display gives a reading of the radon activity concentration in either Bg m or pCi L When in Timer mode the display gives a reading of the gross number of counts When in Pump mode a P is displayed in the center of the screen In all modes of operation a time may be entered in which case the display will show a time in either minutes and seconds mmm ss for Pump and Timer modes or hours and minutes hhh mm for Sniff modes While counting a value will be displayed using either five digits or three digits and an exponent For numbers less than 100 000 five digits are used see For numbers greater than 99 999 three digits and an exponent are used see Figure 1 5 Figure 1 4 An example of the display reading 19864 Figure 1 5 An example of the display reading 123 x2. 104 When the device detects an alpha particle an LED at the top of the display will briefly illuminate to show that it has registered a count as shown in Figure 1 6 Figure 1 6 Registering a Count When the batteries are charging the three decimal points in the center of the display will be illuminated see Figure 1 7 When the batteries are starting to run low the three decimal points in the center of the display will flash see Figure 1 8 Charging Indicator Figure 1 7 Charging Indicator VI Low Battery Indicator Figure 1 8 Low Battery Indicator 1 5 Batteries The VS472 contains rechargeable batteries that are located inside the unit These batteries should not need to be changed during normal operation Battery life will vary depending on the mode the device is used in When in radon sniffer mode with the air pump running fully charged batteries should provide around 18 20 hours of operating time When the low battery indicator light comes on there is about 2 4 hours of operating time left with the air pump running After that the device will cease to function until a powered charger is plugged in Once depleted the batteries will need to be charged for 16 hours to restore full charge To charge the batteries plug the supplied charger into an electrical outlet Only the charger supplied with the instrument should be used remove the cover from the charger jack and insert the end of the charger see Figure 1 3
3. for which the pump will run press the TIMER button enter a time in mmm ss format and press the TIMER button again If you made a mistake follow this same procedure to enter a new time The pump is turned on by pressing the START button and the pump will run until either the pre set time has elapsed or the STOP button is pressed To briefly display the time remaining press the TOGGLE button The display will change to show the time remaining in mmm ss format for a few seconds before automatically switching back to display a P This button may also be used before the count has started or after the count has finished to display the pre set time that has been entered While the pump is running the high voltage indicator will be illuminated as shown in Figure 2 9 HV ON e I DONOT EXPOSE PMT Pump On HV ON 11 bo NOT EXPOSE PMT Pump Off Figure 2 9 Pump Mode Display 18 2 6 Purging Lucas Cells After a Lucas cell has been exposed to radon it must be cleaned immediately to prevent large amounts of radon progeny from accumulating inside Once you have finished sampling place the device in a location with very little radon eg outside and pump air through the cell for at least 15 minutes To further reduce the background in the cell wait for 3 4 hours and pump air through the cell again for at another 10 minutes 1
4. 7 Filter Count Setup 15 2 3 Timed Sniff Modes As well as being able to run indefinitely in Sniff mode the VS472 can run for any pre set time between 1 minute and 30 days In order to enter a time for which to run the device in Sniff mode the power must first be turned on using the ON OFF button Pressing the F4 button will display 000 00 Enter a time in hhh mm format that you would like to sniff for using the number pad and press TIMER button to accept this time If you made a mistake you may press the TIMER button to re enter a time A maximum time of 999 hours and 99 minutes may be entered but if the time entered is greater than 720 hours it will only sniff for 720 hours Once a time has been entered pressing the START button will begin the test During the test the display will show and the keypad will be disabled to ensure an uninterrupted test Once the sniffing has concluded the total average radon concentration will be displayed in Bg m and the results can be transmitted to a Bluetooth enabled device that is paired with the VS472 later Since the keypad is disabled the device can only be turned off with the supplied reset key Insert the key into the charger jack until the display turns black 5 10 seconds Immediately remove the reset key after this happens 2 4 Timer Mode If you have been using the device in one of the other two modes of op
5. 9 Chapter 3 Other Information 3 1 Upper Detection Limits The upper detection limits for each mode are given in Table 3 1 These limits are approximations based on various detector and device characteristics Mode Limit Radon Sniffer Radon Sniffer Five Minute Average Three Minute Gross Counts Five Minute Gross Counts Total Gross Counts 220 x 10 Bq m 220 x 10 Bq m 185 x 10 count 3min 309 x 104 count 5min 167 x 10 count Table 3 1 Approximate Upper Detection Limits 3 2 Summary of Buttons Indicators and Other Functions A summary of the button indicator and air pump functions in the different oper ating modes is give in Table 3 2 20 suonjoung 19410 pue siojeorpug suog Jo reurumg 7 de 2pojJN dung ary epoW Juno epOW 1ogrug uopey 21
6. T EXPOSE PMT HV ON O DO NOT EXPOSE PMT TOGGLE gt gt TOGGLE Remaining Time LI l LI Li Figure 2 8 Counting Display Indicator HV ON e DO NOT EXPOSE PMT HV ON O DO NOT EXPOSE PMT The Timer count mode has an upper display limit of 167 x 10 counts Once this limit has been reached the display will read 167 x 10 and no further counts will be registered Once a Lucas cell has been counted the results can be converted into Bq m or pCi L using the Radon Gas Measurement by Delayed Count program in the On Line Uranium Radiation Safety Toolkit v2 0 at www eic nu 17 2 5 Pump Mode In pump mode the air pump is operated and no other operations are performed This mode may be useful when you wish to take a grab sample with a Lucas cell and only the air pumping feature is required WARNING A Lucas cell or protective light tight cap must be firmly attached to the PMT whenever the VS472 is on even if a count is not being taken Failure to do so could result in damage to the PMT If you have been using the device in one of the other two modes of operation and wish to enter Pump mode you will first need to turn off the power by pressing the ON OFF button for two seconds Turn the power on again with the same button then press the PUMP button A P will appear in the center of the display to indicate that the device is in Pump mode To enter a time
7. T and the 5 minute con centration is labeled LO NG Press the TOGGLE button to change the display between the two guant ties Note The 5 minute average radon concentration is only accurate if the device has been running in Sniff mode for 5 minutes or more Note If the device is turned off while in Sniff mode a clean Lucas cell must be used if using Sniff mode again within 4 hours To change the display to show the concentration in either Bq m or pCi L press the corresponding SNIFF button F5 or F6 When displaying pCi L the value will be displayed with one decimal place as shown in Figure 2 2 1000 Bg m 100 0 pCi L Figure 2 2 Difference in display between Bq m and pCi L Sniff modes If you wish to obtain an average reading over a specific amount of time press the TIMER button enter the time in hhh mm format and press the TIMER button again Neither radon activity concentration indicator will be illuminated meaning that the device is giving an average radon activity concentration over the user defined interval of time A maximum time of 999 hours and 99 minutes may be entered but if the time entered is greater than 12 hours and the device has been sniffing longer than this it will only display an average over the previous 12 hours If the time entered is longer than the time that the device has been running it will display an average for the amount of time that it has been running To disp
8. VS472 Radon Sniffer SHORT DETECT LONG HV ON CH DO NO NOT EXPOSE PMT sa lt CHARGING LOW BATTERY Figure 1 3 Front Plate Controls 1 Main Display 2 Charger Jack and Cover Lucas Cell or Protective Light Tight Cap Pump Connector Threaded Holes for Retainer Bracket Start Button Stop Button F4 Timed Sniff Button D oo 1 OC C A C F5 Sniff Bq m Button 10 F6 Sniff pCi L Button 11 F7 Total Average Button 12 Toggle Button 13 Pump Button 14 Timer Button 15 On Off Button Main Display This is the area where information such as the activity concentra tion of radon the number of gross counts and other information is displayed The information displayed depends on the mode the device is in Charger Jack and Cover The VS472 runs off of internal rechargeable batteries The batteries may be recharged by connecting the supplied charger to this jack The VS472 may be operated while the charger is plugged in The charger jack is also used with the reset key to turn the device off after a timed sniff The reset key is inserted into the charger jack until the power turns off 5 10 seconds Lucas Cell or Protective Light Tight Cap The PMT should be covered by ei ther a Lucas cell or the protective light tight cap The VS472 should never be operated without either one in place doing so could damage the PMT Pump Connector Connects to the air pump located inside of the VS472 Con nect the Exhau
9. e in A Lucas cell can also be filled with air by using the Pump mode as described in To measure the activity inside a Lucas cell by the delayed count method begin by filling a cell with air as described in section 2 1 To count the activity in the Lucas cell first ensure that the HV indicator LED is not illuminated Remove anything that is attached to the PMT place the Lucas cell directly over the PMT and press down firmly to ensure a tight fit Secure the cell using the retainer bracket then start the count see Figure 2 5 Y 8 Lucas Cell Figure 2 5 Lucas Cell Count Setup When using a small Lucas cell follow the same procedure described above but place the small Lucas cell retainer over the cell before securing it in place with the bracket see Figure 2 6 14 i Small Lucas Cell Retainer Small Lucas Cell Figure 2 6 Small Lucas Cell Retainer When a grab sample is taken using a filter the activity can be measured by using the protective light tight cap To measure the activity on a filter first ensure that the HV indicator LED is off Remove the Lucas Cell or protective cap and place a scintillator ZnS coated side up on the PMT Place the filter to be measured on the scintillator put the protective cap over the PMT then start the count see Figure 2 7 Cap _ Filter lt Scintillator ZnS Side Up Figure 2
10. ed This is because when Sniff mode begins the VS472 assumes that there is no radon progeny inside the cell In order to clean a Lucas cell after sampling in Sniff mode move to a location with very low radon gas concentrations and run the pump in either Sniff mode or Pump mode for 20 minutes using the configuration shown in Figure 2 1 The VS472 also has the ability to send its radon concentration readings over a Bluetooth connection Using software supplied by E I C the device is able to send its latest 12 hours of recorded data captured while in sniff mode This data can then be used to further inspect the trends of the measured radon concentrations Please refer to the specific software manual for further details on how to transfer the data from the VS472 2 2 Grab Sampling Setup If an area of low radon concentration must be sampled directly after sampling in an area of high radon concentration and a very accurate result is required a second Lucas cell can be temporarily attached to the VS472 as shown in Figure 2 4 To ensure no stray light enters the Lucas cell attached to the VS472 the secondary Lucas cell should have its window covered 13 Lucas Cell Filter and Desiccant Air Intake Secondary Lucas Cell Figure 2 4 Radon Sniffer Setup With Dual Lucas Cells The air is sampled in this configuration for two minutes The second Lucas cell is then removed This cell can be counted at a later time following the procedur
11. eration and wish to enter Timer mode you will first need to turn off the power by pressing and holding the ON OFF button for two seconds After attaching a Lucas cell or a filter ZnS screen and light tight cap turn on the power by pressing the ON OFF button To enter the time you would like to count for press the TIMER button enter the time in mmm ss format using the number pad then press the TIMER button again If you made a mistake you may repeat this same procedure to enter a new time maximum time of 999 59 may be entered To start the count press the START button The count will begin two seconds after the High Voltage indicator LED illuminates The count stops when either the pre set time has elapsed or the STOP button is pressed When in Timer mode the gross counts are normally shown on the main display To briefly display the time remaining press the TOGGLE button The display will change to show the time remaining in mmm ss format for two seconds before automatically switching back to display the gross counts This button may also be used before the count has started or after the count has finished displaying the pre set time that has been entered An overview of the Timer mode display is shown in Figure 2 8 16 r1 en KEN LI Count Stopped HV ON e DO NO
12. for the location of the charger jack When the batteries are charging the three center decimal points should be illuminated see The batteries will automatically stop charging once 16 hours have elapsed The unit may still be operated while the batteries are charging 1 6 Filter and Desiccant The filter and desiccant are both contained inside a plastic tube Air should pass through this tube before entering the Lucas cell The filter removes radon progeny from the air before it enters the Lucas cell so that radon levels can be accurately calculated The desiccant removes excess moisture from the air ensuring consistent plate out of radon progeny inside the Lucas cell Two types of desiccants are provided Drierite and gel When the Drierite has become saturated it will turn pink The Drierite may be restored by removing it from the plastic tube and heating it at 200 C 400 F for about 15 minutes or until it turns blue The gel will not become saturated as quickly When the gel becomes saturated it clumps together and turns translucent The gel cannot be restored It must be replaced once it becomes saturated 10 Chapter 2 Operating Modes 2 1 Radon Sniffer Mode Radon sniffer mode is the standard mode of operation To run the device in this mode turn the power on by pressing the ON OFF button and push either the SNIFF Bq m button or the SNIFF pCi L button In Sniff mode the VS472 pumps air th
13. lay an average radon concentration since sniffing began press F7 Pressing the STOP button will reset the starting point of this average so that future presses of the F7 button will display an average over the time since pressing STOP To resume displaying the 15 second average radon concentration press the TOGGLE button Figure 2 3 shows the various display options when in one of the Sniffer modes 12 SHORT LONG SHORT LONG taa Ham Cobo H Radon Activity Concentration Radon Activity Concentration Bq m or pCi L Five Minute Average Bq m or pCi L F7 Button TOGGLE TIMER Button Button time F7 Button SHORT LONG SHORT LONG LIII a I Ii I I F7 Button Radon Activity Concentration Radon Activity Concentration Running Average Average over User Defined Time Bq m or pCi L Bq m or pCi L Figure 2 3 Radon Sniffer Modes After sampling in an area of high radon concentration the lower limit of de tection will be temporarily increased due to radon progeny inside the Lucas cell If you immediately move to an area of low radon concentration the error in the reading will temporarily increase If the VS472 has not been turned off it should recover to about 5 of its peak value within 5 minutes If the power is turned off while in Sniff mode a clean Lucas cell must be used the next time that this mode is enter
14. nvironmental E Instruments Canada Inc VS472 Radon Sniffer User s Manual Firmware 3 0 Environmental Instruments Canada Inc http www eic nu WARNING Never operate this device unless a Lucas cell or protective light tight cap is firmly in place over the PMT Photomulti plier Tube Doing so could damage the PMT Contents 1 Overview of Device 1 1 Introduction a 1 2 Components and Equipment 1 4 Display Overview 1 5 Batteries sson oe Rom go d A e Baw A eae a a 1 6 Filter and Desiccant 2 0 a 2 Operating Modes 2 1 Radon Sniffer Mode 2 2 Grab Sampling Setup 2 3 Timed Sniff Modes llle 2 4 Timer Model 2 5 PumpModel lens 2 6 Purging Lucas Cell llle 3 Other Information 3 1 Upper Detection Limits 3 2 Summary of Buttons Indicators and Other Functions 11 11 13 16 16 18 19 Chapter 1 Overview of Device 1 1 Introduction The VS472 is a radon sniffer that utilizes a zinc sulfide coated Lucas cell coupled to a PMT Photomultiplier Tube along with a small air pump to detect radon levels Air is taken in and passed through a filter and desiccant to remove radon progeny and moisture This air then circulates through a Lucas cell where alpha particles are detected When sniffer mode is entered the VS472 assumes that a clean Lucas cell i e no radioactive contamination in the cell has been attached As air is sampled rad
15. on progeny will accumulate in the cell The VS472 calculates the expected levels of radon progeny in the cell and subtracts these values in order to obtain the radon levels The VS472 also implements several other modes that allow gross counts to be displayed or the air pump to be operated independently 1 2 Components and Equipment A charger Lucas Cell protective light tight cap air hoses a filter desiccant tube a retainer bracket and a reset key are included with the VS472 Filter and Gel Desiccant Lucas Cell me Ki Charger Reset Key I Air Hoses Retainer Bracket Figure 1 1 Equipment Included With The VS472 Protective Light Tight Cap Charger The charger is used to recharge the internal batteries Reset Key The reset key is used to turn off the VS472 either during or after a timed sniff test Lucas Cell Zinc sulfide coated cell where alpha particles are detected A Lucas cell or protective light tight cap must be firmly in place over the PMT before the device is turned on failure to do so could result in damage to the PMT One side of the Lucas cell is labeled Exhaust which connects to the VS472 The other side is labeled Intake which is connected to the filter and desiccant with the black coiled air hose Protective Light Tight Cap This cap is used to protect the PMT when the Lucas cell is not in place Also by placing a scintillator and a filter under the cap grab samples of rad
16. on progeny may be counted See for details Air Hoses Air hoses are used to connect the filter and desiccant Lucas cell and internal air pump together Only the supplied black air hoses should be used with this device and the air hose that is connected to the Intake side of the Lucas cell should have no fewer than five coils These measures prevent stray light from entering the PMT When sampling the general area the filter desiccant tube may be tucked between the VS472 and the leather carrying case For probing into air ducts and other difficult to access sources of radon remove the filter desiccant tube from the leather carrying case and hold it near the location to be tested Desiccants and Filters Cylindrical tubes contain the desiccants and filters The filter is used to remove radon progeny and other particulates from the air The desiccant is used to remove moisture from the air ensuring consistent plate out of radon progeny inside the Lucas cell See for details Retainer Bracket This bracket is used to hold the Lucas cell in place over the PMT It is attached to the face plate with two screws A diagram showing the basic system components is given as Figure 1 2 Lucas Cell Minimum Five Coils Y Filter and Desiccant Air Intake Figure 1 2 Overall System Schematic 1 3 Controls An overview of the front face plate controls is given in Figure 1 3 Environmental Instruments Canada Inc http www eic nu Model
17. rough the Lucas cell and calculates the radon activity concentration in the air When using the device in this mode the tube containing filter and desiccant should be connected to the Intake side of the Lucas cell and the Exhaust side of the Lucas cell should be connected to the pump connector on the VS472 see Figure 2 1 The PMT should be covered at all times when in this mode of operation To exit radon sniffer mode and enter one of the other modes of operation the power must first be turned off by pressing the ON OFF button Exhaust Intake Side Side Minimum Five Coils Filter and Desiccant x Air Intake Figure 2 1 Radon Sniffer Setup 11 Note Only the large Lucas cells should be used while in Sniff mode otherwise an inaccurate result may be displayed In this mode one of two guantities is normally displayed a 15 second average radon activity concentration or a 5 minute average radon activity concentration The 15 second average concentration is based on the last 15 seconds of sampling and is updated every 3 seconds The 5 minute average radon concentration is averaged over the last 5 minutes and is updated every 15 seconds This average is more useful in areas with low radon concentrations as the 15 second value may tend to vary when the concentration is low Each guantity also has its own indicator point located at the top of the display The 15 second average concentration is labeled SHOR
18. st side of the Lucas cell to this connector with a short length of black air hose The pump should not be run while there is nothing inserted in this connector Start Button This button begins the count starts the pump or starts the un interrupted sniffing test depending on what mode is entered Stop Button This button stops the count in Timer mode stops the pump in Pump mode and resets the running total counts in Sniff mode F4 Timed Sniff Button After pressing this button a time is entered for which the VS472 will sniff F5 Sniff Bq m Button This button is used to enter sniff mode in which the VS472 can display either a 15 second radon activity concentration a five minute average radon activity concentration an average concentration over a time specified by the user or an average concentration since entering Sniff mode If Sniff mode is already entered pressing this button will make the display show readings in Bg m F6 Sniff pCi L Button Sniff mode can also be entered using this button If Sniff mode is already entered pressing this button will make the display show readings in pCi L F7 Total Average Button Pressing this button while in Sniff mode will show a reading of the average radon concentration since sniffing began or since the stop button was last pressed Toggle Button Used to toggle display between a 15 second radon activity con centration Short and a 5 minute average radon activity concentration Long
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