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Abacus Operation Manual_______________________________ Table of Contents

Quick Start Reference Guides

Windows Mobile Devices ........................................................................................2 Windows® PC ......................................................................................................6 PalmOS .............................................................................................................10

The Ratemeter Screen ...................................................................................12 Total Count Screen ........................................................................................14 Total Dose Screen ..........................................................................................16 Data Logging Screen ......................................................................................17 Common Procedures .....................................................................................18

Establishing the Background Count ..............................................................18 Environmental Area Monitoring ....................................................................18 Checking for Surface Contamination .............................................................18 Determining Activity ...................................................................................19 Basics of Radiation and Its Measurement .......................................................19 Radiation Measurement Units ......................................................................20

Specifications....................................................................................................21 Source Calibration..... ......................................................................................22

Peanut Correction Factor and the Pancake Correction Factors ............................22 Exposure Rate Calibration ...........................................................................24

Frequently Asked Questions.............................................................................26 Warranty............................................................................................................27

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Quick Start Reference Guide for Windows Mobile Devices

Connecting for the First Time 1. Install the Abacus software to the WINDOWS MOBILE DEVICE: a. Connect your Windows Mobile Device to your PC and ensure that ActiveSync connects. b. Insert the Abacus installation CD into your CD drive. (If the Abacus Installer does not start automatically, find "AbacusInstall.exe" on the installation CD and run it.)

c. Click the "Install Abacus for PocketPC" button to begin the installation process. Follow the prompts to complete the installation process. 2. Power the Abacus on by moving the on/off switch on the end of the handle to the "On" position (fig. 1). A five-note sequence of tones will play indicating that the Abacus is working and ready to connect to a Windows Mobile Device (WINDOWS MOBILE DEVICE). The LED (fig. 2) should be glowing solid red and clicks should be heard. 3. Make sure the supporting Bluetooth-enabled WINDOWS MOBILE DEVICE is powered on and Bluetooth is enabled. Different WINDOWS MOBILE DEVICEs use different methods for connecting to Bluetooth devices such as the Abacus. Often, WINDOWS MOBILE DEVICEs require that a "partnership" be established before connecting with a software application. Consult your manufacturer's instructions for installing the Bluetooth card before attempting to connect to the Abacus. These instructions were written using the Dell Axim X51, but should be reasonably accurate for other windows mobile devices. [Note: The Abacus is now working. The audio response can be used to detect changes in count rate and, if a Hardware Alarm has been set, the internal alarm will sound when the set exposure rate is exceeded.]

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a. Tap Start > Settings > Connections tab.

b. Tap Bluetooth. In the Mode tab, make sure "Turn on Bluetooth" is checked.

c. Go to the Devices tab and tap New Partnership. Your device searches for other devices with Bluetooth capabilities, and displays them in the list.

d. Tap the entry for "Abacus" followed by the serial number and tap Next.

e. In Passkey, leave the passkey blank, and tap Next. If a screen appears that requires a password

to be entered, enter a single character and tap Next.

f. Tap Yes to add the Abacus to your device list.

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g. Check Serial Port and tap Finish.

h. The Abacus will now appear on your Devices list. Tap the COM Ports tab.

i. Tap New Outgoing Port.

j. Select the Abacus and tap Next.

k. Make sure Secure Connection is not checked and tap Finish. Note the COM Port number that the Abacus is connected through, as you will need it later.

l. The Abacus will now be displayed on the COM Ports tab. Use the Bluetooth manager on the Windows Mobile Device to determine which port number is designated as the Bluetooth COM port. If two ports are listed, select the outgoing port. Note this number for later use.

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4. Start the Abacus software application by tapping the "SEI Abacus" icon in the Programs folder on your Windows Mobile Device.

5. A startup screen will appear for a few seconds while the program loads.

6. The application will open to the Connection screen. Select the COM port number determined earlier from the dropdown list and tap the Open Connection button. Depending on your particular Windows Mobile Device you may also need to find and/or select a Bluetooth device. The Abacus will be displayed in the Found Devices list as "Abacus" followed by the unit's six-digit serial number.

7. A four-note ascending series of tones from both the Abacus and the Windows Mobile Device signals that a connection has been successfully made. The LED will now flash with each count detected. If this is the first use, the Abacus will open to the Ratemeter screen.

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Quick Start Reference Guide for Windows® PC

Connecting for the First Time 1. Install the Abacus software to the PC: a. Insert the Abacus installation CD into your CD drive. (If the Abacus Installer does not start automatically, find "AbacusInstall.exe" on the installation CD and run it.)

b. Click the "Install Abacus for Windows" button to begin the installation process. Follow the prompts to complete the installation process. 2. Power the Abacus on by moving the on/off switch on the end of the handle to the "On" position (figure 1). A five-note sequence of tones will play indicating that the Abacus is working and ready to connect to a desktop or laptop. The LED (fig 2) should be glowing solid red and clicks should be heard. 3. Make sure Bluetooth is enabled on your PC.

Different PCs use different methods for connecting to Bluetooth devices such as the Abacus. Often, PCs require that a "partnership" be established before connecting with a software application. Consult your manufacturer's instructions for installing the Bluetooth adapter before attempting to connect to the Abacus. [Note: The Abacus is now working. The audio response can be used to detect changes in count rate and, if a Hardware Alarm has been set, the internal alarm will sound when the set exposure rate is exceeded.]

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a. Right-click on the Bluetooth icon ( ) in the System Tray and select Bluetooth Setup Wizard.

b. In the Bluetooth Setup Wizard, choose "I know the service I want to use and I want to find a Bluetooth device that provides that service" and click Next.

c. Select the Bluetooth Serial Port service and click Next.

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d. Make sure Show all devices is selected. Select the entry for "Abacus" followed by the serial number and click next.

e. On the completion page, make sure Start the connection is NOT checked. Click the Configure button.

f. Make sure Secure Connection is NOT checked. Note the COM Port number that the Abacus is connected through, as you will need it later. Click OK.

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g. Click the Finish button.

4. Start the Abacus software application by selecting the "Abacus" icon from Start > Programs > Abacus on your computer. The application will open to the Connection screen. Select the COM port number determined earlier from the dropdown list and click the Open Connection button.

5. A four-note ascending series of tones from both the Abacus and the WINDOWS MOBILE DEVICE signals that a connection has been successfully made. The LED will now flash with each count detected. If this is the first use, the Abacus will open to the Ratemeter screen.

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Quick Start Reference Guide for PalmOS

Connecting for the First Time 1. Install the Abacus software to the Bluetooth-enabled Palm device: a. Insert the Abacus installation CD into your CD drive. (If the Abacus Installer does not start automatically, find "AbacusInstall.exe" on the installation CD and run it.)

b. Click the "Install Abacus for Palm" button to begin the installation process. Follow the prompts to complete the installation process. c. HotSync your Palm. The Abacus application will initially show up in your Unfiled folder. 2. Power the Abacus on by moving the on/off switch on the end of the handle to the "On" position (figure 1). A five-note sequence of tones will play indicating that the Abacus is working and ready to connect to a Windows Mobile Device (WINDOWS MOBILE DEVICE). The LED (figure 2) should be glowing solid red and clicks should be heard. [Note: The Abacus is now working. The audio response can be used to detect changes in count rate and, if a Hardware Alarm has been set, the internal alarm will sound when the set exposure rate is exceeded.]

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3. Make sure the supporting Bluetooth-enabled PalmOS device is powered on and Bluetooth is enabled, and tap the SEI Abacus icon.

4. The application will open to the Connection screen. Tap Open Connection.

5. If this is the first time you've connected to the Abacus with this device, the Bluetooth Discovery screen will display. Have it show Nearby devices. Tap the entry for "Abacus" followed by the serial number and tap Next.

6. The PalmOS device will show the Connecting message while it connects to the Abacus.

7. A four-note ascending series of tones from both the Abacus and the Palm signals that a connection has been successfully made. The LED will now flash with each count detected. If this is the first use, the Abacus will open to the Ratemeter screen.

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The Ratemeter Screen

1. The box near the top of the screen displays the current average rate and units. 2. Tap the zero button to reset the rate (for both tubes) to zero. 3. Use the Units dropdown box to pick units (CPM, CPS, µR/h, mR/h, or µSv/h). Selecting CPM or CPS will display the counts per minute or counts per second from the "pancake" tube; if "comp" (i.e., gamma compensated) is checked the counts attributable to gamma and x radiation will be subtracted in the displayed value. The subtraction is based on the calibration settings, described later in this manual. Selecting µR/h, mR/h, or µSv/h will display microroentgens per hour, milliroentgens per hour, or microsieverts per hour based on the "peanut" tube. 4. The description field is for entering a description for a particular measurement. In the dropdown list, enter a new description, or select a previously entered descriptor, to be added to your report. 5. The "Manage" button allows the user to delete and modify previously entered survey descriptions. 6. The "Add" button adds the description in the description field to a list of previously entered descriptions for easy retrieval for later surveys via the dropdown list. 7. Tap the "Count" button at the bottom of the Ratemeter screen to enter the "Total Counts" screen. 8. Tap the "Dose" button at the bottom of the Ratemeter screen to enter the "Total Dose" screen. 9. Check or uncheck the "comp" checkbox to turn gamma compensation on or off. Note that this only affects the displayed rate when "CPM" or "CPS" is selected. 10. Use the Response dropdown box to choose between slow (28 sec.), med (14 sec.), or fast (7 sec.) response times. This affects how quickly the displayed rate changes in response to changes in radiation levels. The response can be changed at any time; the display will be updated within one second to the new averaged value. 11. Use the Audio dropdown box to select audio response to both tubes; pancake tube only, peanut tube only, or silent operation. 12. Use the Vol dropdown box to control volume (loud, medium, soft). This will have no effect if the Audio is set to silent. 13. Immediately below the Vol dropdown box is the Abacus battery voltage. This will change as the batteries used in the Abacus are depleted, from a high of around 3.2V down to as low as 1.8V. When the batteries get down to 1.5V this text will change to red indicating that you should

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change your (2 AA) batteries and unless "silent low battery alarm" is checked in the alarms setting screen, a chirp will play approximately every ten seconds. 14. The Log Rate button allows the current rate to be logged in memory. Rates can be added at any time, and can be saved as text (*.txt) or comma delimited (*.csv) files. (Note: Tap the manage button to delete or re-order the stored text.) 15. Tap the View Report button at any time to view the complete report for all data points currently stored in memory.

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Total Count Screen

1. The box near the top of the screen displays the current total counts. 2. Edit the "Acquisition Time" field to enter the total time for which you want to take your count (acquisition time). Enter zero or leave blank to acquire continuously. 3. "Elapsed Time" shows the amount of time that has passed since starting the acquisition. 4. The description field is for entering a description for a particular measurement. In the dropdown list, enter a new description, or select a previously entered descriptor, to be added to your report. 5. The "Manage" button allows the user to delete and sort previously entered survey descriptions. 6. The "Add" button adds the description in the description field to a list of previously entered descriptions for easy retrieval for later surveys via the dropdown list. 7. Tap the "Rate" button at the bottom of the Total Counts screen to enter the "Ratemeter" screen. 8. Tap the "Dose" button at the bottom of the Total Counts screen to enter the "Total Dose" screen. 9. Check or uncheck the "comp" checkbox to turn gamma compensation on or off. Note that this only affects the displayed rate when "CPM" or "CPS" is selected. 10. The "Begin" button starts the acquisition for the set amount of time in the "Acquisition Time" field. A quick three beeps will sound at the end of the set acquisition time. 11. "Stop" will stop the acquisition. If the "Acquisition Time" field is blank, the abacus will continue to take readings until this button is tapped. 12. "Clear" will reset the total accumulated counts and elapsed time to zero. If you tap "Stop", then tap "Begin" without clearing your reading, the time will begin where you stopped your acquisition. If you tap "Clear", the acquisition will start from the beginning of the set acquisition time. 13. The Log Count button allows the current count to be logged in memory. The report can be accessed at any time and can be saved as text (*.txt) or comma delimited (*.csv) files. 14. Immediately below the Vol dropdown box is the current Abacus battery voltage. This will change as the batteries used in the Abacus are depleted. When the batteries get down to 1.5V this text will change to red indicating that you should change your (2AA) batteries and unless "silent low battery alarm" is checked in the alarms setting screen, a chirp will play approximately every ten seconds.

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15. Tap the View Report button at any time to view the complete report for all data points currently stored in memory. 16. Enter a background to be subtracted from counts.

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Total Dose Screen

1. The box near the top of the screen displays the current total dose. 2. The "Reset Dose" button will zero the dose and restart the dose accumulation. 3. Displays the time and date at which the dose accumulation was started. 4. "Total Accumulation Time" shows the amount of time which has elapsed since starting the acquisition. 5. Tap the "Rate" button at the bottom of the Total Dose screen to enter the "Ratemeter" screen. 6. Use the "Units" dropdown box to select a unit of measurement. 7. The "Batt" (Battery Voltage) will change as the batteries used in the Abacus are depleted, from a high of around 3.2V down to as low as 1.8V. When the batteries get down to 1.5V, the text will change to red indicating that you should change your (2AA) batteries and unless "silent low battery alarm" is checked in the alarms setting screen, a chirp will play approximately every ten seconds. 8. Tap the "Count" button at the bottom of the Total Dose screen to enter the "Total Counts" screen.

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Data Logging Screen

Found under the Utility Menu, the Data Logging Screen can only be accessed while the Abacus is connected to the computer. 1. Set the frequency with which the Abacus will log data points. 2. Select a name for the data file. 3. Choose between a "txt" (text) file and a "csv" (comma separated values) file. 4. Select the unit of measurement for the peanut tube on the Abacus. 5. Select the unit of measurement for the pancake tube on the Abacus.

On a Windows Mobile Device, the data file is saved to the Abacus folder in My Documents on the device you are using. On a Windows Computer, the data file is saved to the Abacus_Win directory under C:\Program Files\Abacus_Win. Datalogging has not yet been implemented in the PalmOS software. Check our website at www.seintl.com for updates.

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Alarm Settings The Abacus has two different types of alarms; Software and Hardware Alarms. The software alarm has settings for both Exposure Rate Alarm and an Accumulated Dose Alarm. Access the Alarm Settings through the Utility drop down menu. Exposure Rate Alarm The Exposure Rate Alarm units can be set to µR/hr, mR/hr, µS/hr, and mS/hr. If the "Latch" is checked, then when the alarm is triggered, it stays on until the alarm is turned off by the user. When the "Silent Alarm" is checked, the alarm is only visible on the screen and not audible. Accumulated Dose Alarm The Accumulated Dose Alarm units can be set to µR, mR, µS, and mS. Hardware Alarm In the Calibration menu, you can set a Dose Rate Alarm in the hardware of the Abacus. This means that even if the unit is not connected to a PC, PocketPC, or Palm, then the alarm in the Abacus will still alert if you exceed the set threshold. This enables the user to conduct a rough "Audio Y/N" survey to check for the presence of radiatioactive material without a connected computer and still alert the user of any higher levels present. Preferences Under the "Surveyor's Name", you can add a name or other identifier that will append to the generated reports. If you know the isotope you are surveying, you can select it from the drop down box and calculate the activity in your choice of available units of measurement. Clear counts without confirmation. For example, if you are on the Count Screen and you tap the clear button, a message will popup asking you to confirm that you want to clear the data. If the "Clear Counts without Confirmation" is checked, then you will not receive the popup warning asking you to confirm.

Common Procedures The following sections give instructions for several commonly-used procedures. With any procedure, the user must determine the suitability of the instrument or procedure for that application. Establishing the Background Count Normal background radiation levels vary at different locations, time, even in different areas of the same room. To accurately interpret the readings you get on the Abacus, it is good to establish the normal background radiation count rate for each area you plan to monitor. A ten-minute average is moderately accurate. You can repeat it several times and see how close the averages are. To establish a more accurate average, take a one-hour timed count. If you need to determine whether there is prior contamination, take averages in several locations and compare the averages. Environmental Area Monitoring You can keep the Abacus on the Ratemeter Screen whenever you want to monitor the ambient radiation, and look at it from time to time to check for elevated readings. If you suspect an increase in ambient radiation, use the timer and take a five or ten minute count, and compare the average to your average background count. If you suspect an increase that is too small to detect with a short timed reading, you can take a longer count (for example 6, 12, or 24 hours). Checking for Surface Contamination CAUTION: Never touch the Abacus to a surface that may be contaminated. You may contaminate the instrument.

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Determining Activity If you know which radionuclide (isotope) you are surveying, you can determine the activity for a variety of radionuclides by using the Abacus' pre-determined compensation factors. 1. While taking a survey, tap the utility menu. 2. Check the "Calculate Activity" check box and choose a unit of measurement that you would like to use for determining your activity. 3. Next, Choose the radionuclide from the dropdown menu (if present). Available choices from the factory settings are Cs-137 (21.38%), C-14 (4.12%), Pm-147 (8.21%), TC-99 (12.71%), Cl-36 (25.88%), Sr/Y-90 (26.15%), P-32 (26.00%), I-131 (23.70%), S-35 (4.80%), and Th-230 (6.77%). 4. Tap "OK". 5. In the Ratemeter Screen, select "Activity" from the "Units" dropdown menu. You should now see the activity determined in the units of measurement that you chose. The isotope you are surveying is displayed above the unit of measurement.

Basics of Radiation and Its Measurement This chapter briefly tells what radiation is and how it is measured. This information is provided for users who are not already familiar with the subject. It is helpful in understanding how the Abacus works and in interpreting your readings. Ionizing Radiation Ionizing radiation is radiation that changes the structure of individual atoms by knocking off the outer shell electrons, or "ionizing" them. Substances that produce ionizing radiation are called radioactive. Radioactivity is a natural phenomenon. Nuclear reactions take place continuously on the sun and all other stars. The emitted radiation travels through space, and a small fraction reaches the Earth. Natural sources of ionizing radiation also exist in people and in the ground. The most common of these are uranium and its decay products. Ionizing radiation is categorized into four types: X-rays are manmade radiation produced by bombarding a metallic target with electrons at a high speed. X-rays are electromagnetic radiation of the same nature as light waves and radio waves, but at extremely short wavelength, less than 0.1 billionth of a centimeter. They are also called photons. The energy of X-rays are millions of times greater than that of light and radio waves. Because of this high energy level, X-rays penetrate a variety of materials, including body tissue. Gamma rays are produced in the nucleus while x-rays are created in the electron shell. Gamma rays are almost identical to X-rays. Gamma rays generally have a shorter wavelength than X-rays. Gamma rays are very penetrating; thick lead shielding is generally required to stop them. Gamma rays are produced in the nucleus while x-rays are created in the electron shell. Beta radiation A beta particle consists of an electron emitted from an atom. It has more mass and less energy than a gamma ray, which has no mass, so it doesn't penetrate matter as deeply as gamma and X-rays.

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Alpha radiation An alpha particle consists of two protons and two neutrons, the same as the nucleus of a helium atom. It generally can travel no more than 1 to 3 inches in air before stopping, or can be stopped by a piece of paper. Decay: When an atom emits an alpha or beta particle or a gamma ray, it becomes a different type of atom. Radioactive substances may go through several stages of decay before they change into a stable, or non-ionizing, form. For example; U-238 has 14 different stages of decay before it stabilizes. An element may have several forms, or isotopes. A radioactive isotope of an element may be called "radioisotope". However, the more correct term is radionuclide. For more information about surveying for a particular radionuclide, see "Determining Activity". Half-life: Each radionuclide has a characteristic half-life, which is the time required for half of a quantity of the material to decay. Radiation Measurement Units Several different units are used to measure radiation, exposure to it and dosage. A Roentgen is the amount of X-radiation or gamma radiation that produces one electrostatic unit of charge in one cc of dry air at 0° C and 760 mm of mercury atmospheric pressure. The Abacus displays in milliroentgens per hour (mR/hr). A RAD is the unit of exposure to ionizing radiation equal to an energy of 100 ergs per gram of irradiated material. This is approximately equal to 1.07 roentgens. A REM is the dose received by a human from exposure to a RAD. It is the number of RADs multiplied by the quality factor of the particular source of radiation. The REM and millirem are the most commonly-used measurement units of radiation dose in the U.S.. For most purposes, we can consider 1 rem= 1rad. A Sievert is the standard international measurement of dose. One Sievert is equivalent to one hundred REM. A Microsievert (µSv) is one millionth of a Sievert. A curie is the amount of radioactive material that decays at the rate of 37 billion disintegrations per second, approximately the decay rate of one gram of radium. Micro curies (millionths of a curie) and Pico curies (trillionths of a curie) are also often used as units of measurement. A Becquerel (Bq) is equivalent to one disintegration per second.

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SPECIFICATIONS Detector: Detector 1: Halogen-quenched Geiger-Mueller tube. Effective diameter.1.75" (45 mm). Mica window density: 1.5 - 2.0 mg/cm2. Detector 2: Halogen-quenched Geiger-Mueller tube. Effective dia.0.306" (7.77 mm). Display: Windows PC or Laptop, Windows Mobile Device or PalmOS Handheld Operating Range: µR/h - 0 to 2,000,000 µR/h mR/h - 0 to 2,000 mR/h µSv/h - 0 to 20,000 µSv/h CPM - 0 to 750,000 cpm CPS - 0 to 12,500 cps Total counts - >99,999,999,999 Alarms: Hardware (Dose Rate). Software (Dose Rate, Accumulated Dose, and Low Battery). Gamma Sensitivity: ~7.5 CPS/mR/hr referenced to Co60. Smallest detectable level for I-125 is .02 Ci at contact. Averaging Periods: Display updates every second Response time: Slow = 30 seconds, Medium = 15 seconds, and Fast = 10 seconds Timer: Unlimited Alert Range: mR/hr: 0 to 50 CPM: 0 to 160,000

Accuracy: ± 15% over the entire operating range Beeper: Operational in Audio mode only Anti-Saturation: Readout holds at full scale in fields up to 100 times the maximum reading? Temperature Range: -10° to +50° C , 14° to 122° F Power: 2 AA Batteries.

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Source Calibration Calibration values are stored in the Abacus hardware and are not reliant on the specific PDA or PC running the Abacus software. This means that the Abacus is calibrated alone and is not considered part of an instrument/PDA. The calibration values are transferred from the Abacus to the PDA/PC at the time of connection. It is recommended that an un-attenuated (or minimally attenuated) gamma beam be used for Steps I and II of the calibration procedure below if at all possible. Calibration Procedure Step I: Peanut Correction Factor and the Pancake Correction Factors This procedure does not need to be performed except during initial factory set-up unless there is some reason to suspect that the correction factors are in error. Step-by-Step Procedure for Peanut Tube 1. Ensure the Abacus is powered on and successfully connected to a PDA or PC through the Abacus application. 2. On the calibration screen check the "Cal Display" box, and then tap the "Close" button. Selecting the Cal Display will show raw count data for both tubes on the "Total Counts" screen. 137 3. Expose the Abacus to a relatively high Cs beam with a known exposure rate. This should be near the top end of peanut tube's range, perhaps 1 R/h. This beam should be centered on the peanut tube. 4. Go to the "Total Counts" screen. Begin a 60-second acquisition. Note that two "new" numbers are displayed on this screen to the left of the "Stop" and "Clear" buttons. The top-most of these is the number of (dead-time corrected) counts observed in the peanut G-M tube during the count; the lower is the number from the pancake G-M tube and should match the value shown in the main display. 5. When the acquisition is complete, divide the peanut (upper) value by the known exposure rate to determine the CPM/mR/hr for the peanut tube. For example, if the peanut value is 574,973 counts (in one minute) and the exposure rate is 1143 mR/h then the result would be 503 CPM/mR/hr. 6. Perform a 60-second acquisition at a substantially lower exposure rate (around 10 mR/h) but well above background. 7. Again divide the resultant peanut value by the known exposure rate to determine the CPM/mR/hr. For example, if the peanut value is 4,157 counts (in one minute) and the exposure rate is 8.35 mR/h then the result would be 498 CPM/mR/hr, respectively. 8. Average the CPM/mR/hr values. For the above example values the average would be 500.5 for the peanut tube. 9. Calculate the square root of this average. (In this example this is 22.4). The observed CPM/mR/hr values must be within the average ± the square root of the average, e.g. the observed values must be between 478.1 and 522.9 in this example, in order to ensure linear response over the range of the instrument. 10. If the values are out of tolerance, adjust the "Peanut Correction Factor" on the calibration screen and repeat the test. If the higher-range CPM/mR/hr value is higher than the lower range value, there is too much correction being performed. Increase the Peanut Correction Factor. If the higher-range CPM/mR/hr value is lower than the lower range value, there is not enough correction being performed. Decrease the Peanut Correction Factor.

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Step-by-Step Procedure for Pancake Tube 1. Ensure the Abacus is powered on and successfully connected to a PDA or PC through the Abacus application. 2. Expose the Abacus to a relatively high 137Cs beam with a known exposure rate. This should be near the top end of pancake tube's range, perhaps 100 mR/h. Make sure the beam is centered on the pancake tube. 3. Go to the "Total Counts" screen. Begin a 60-second acquisition. 4. When the acquisition is complete, divide the number of pancake counts by the known exposure rate to determine the CPM/mR/hr for the pancake tube. For example, if the pancake value is 517,127 counts (in one minute) and the exposure rate is 137.8 mR/h then the result would be 3753 CPM/mR/hr. 5. Perform a 60-second acquisition at a substantially lower exposure rate (around 10 mR/h) but well above background. 6. Again divide the resultant pancake value by the known exposure rate to determine the CPM/mR/hr. For example, if the pancake value is 38,854 counts (in one minute) and the exposure rate is 10.1 mR/h then the result would be 3846 CPM/mR/hr, respectively. 7. Average the CPM/mR/hr values. For the above example, values the average would be 3,799.5 for the pancake tube. 8. Calculate the square root of this average. (In this example this is 61.6). The observed CPM/mR/hr values must be within the average ± the square root of the average, e.g. the observed values must be between 3737.9 and 3861.1 in this example, in order to ensure linear response over the range of the instrument. 9. If the values are out of tolerance, adjust the "Pancake Correction Factor" on the calibration screen and repeat the test. If the higher-range CPM/mR/hr value is higher than the lower range value, there is too much correction being performed. Increase the Peanut Correction Factor. If the higher-range CPM/mR/hr value is lower than the lower range value, there is not enough correction being performed. Decrease the Peanut Correction Factor.

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Step II: Exposure Rate Calibration Discussion The exposure rate calibration pertains only to the peanut G-M tube. The dead-time correction is responsible for keeping the response linear so only one "Calibration Factor" is needed for the entire exposure rate measurement range of the instrument. The "Calibration Factor" is the number of counts-per-minute observed for each milliroentgen-per-hour of exposure rate. The default value of about 500 CPM/mR/hr is normally a good one although the value calculated in Step I above can be used instead. Calibration procedures generally call for calibrations to be performed at approximately 80% and 20% of all ranges. Given that the Abacus really only has one range (0-5000 mR/h), this would imply that a two-point calibration at 4000 mR/h and 1000 mR/h would be sufficient. We believe that more calibration points than this should be used to demonstrate accuracy and linearity. Step-by-Step Procedure 1. Ensure the Abacus is powered on and successfully connected to a PDA or PC through the Abacus application. 137 2. Expose the Abacus to a Cs beam with a known exposure rate. Make sure the peanut tube is centered in the beam. 3. Compare the observed exposure rate with the known exposure rate. These should be within 10% of one another. 4. Repeat steps 2 and 3 for a range of different values. The following are suggested as appropriate calibration points: 4000 mR/h 1000 mR/h 400 mR/h 100 mR/h 40 mR/h 10 mR/h 4 mR/h 1 mR/h The standard deviation is estimated:

=

50 r = = 9.4 cpm 0.75 t

Where r = the count rate in CPM and t=the counting time in minutes. A count rate can be expected to vary by two standard deviations most of the time and may vary by three standard deviations ~5% of the time. Variation of only one standard deviation in this example results in a number swing of 18.8%, greater than the allowable 10% precision. Two standard deviations, the normally expected variation means the value would be 0.1 mR/h ±37.6%. For this reason we do not recommend attempting to calibrate below about 1 mR/h or so.

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Step III: Efficiency Calibration

1. Ensure the Abacus is powered on and successfully connected to a PDA or PC through the Abacus application. 2. Place the Abacus in the location and position in which the efficiencies will be determined. 3. Go to the "Total Counts" screen. Begin a 60-second acquisition with no source near the Abacus. 4. When the acquisition is complete, record the number of counts as "background." 5. Place the source at a fixed distance, typically one centimeter, from the pancake detector entrance window protective screen. 6. Perform a 60-second acquisition. 7. When the acquisition is complete, record the number of counts observed. 8. Calculate the percent efficiency for that isotope using the following formula:

% efficiency =

( R s - Rb )

A

× 100

Where Rs = sample count rate in cpm (from step 7); Rb = background count rate in cpm (from step 4); A = activity of source in dpm. 9. Repeat steps 5-8 for as many different sources as desired. When complete, Go to the Calibration screen accessed through the Utility Menu. Check "Enable Edit", and enter the date. Access the "Edit Efficiencies" screen. Check "Enable Edit", and enter the isotope abbreviations and calculated activities . Click OK. Click "Write", and then "Yes".

25

Frequently Asked Questions Problem WHY DOES THE ABACUS NOT TURN ON? WHY IS THE ABACUS DROPPING CONNECTIONS? WHY AM I UNABLE TO CONNECT? Solution No battery or Dead Battery - Replace battery Low Battery -Replace battery. Range is limited to 10 meters line of sight. Turn the Abacus off and leave it off for at least one minute. Check for a solid red LED. Check that the Bluetooth radio in your computer or handheld is turned on. Check that the COM port of the Bluetooth connection that you select during the launch of the Abacus software is the same as the established partnership. WHY DO THE READINGS APPEAR TO BE SOMETHING OTHER THAN WHAT THEY SHOULD BE? The GM tube or the connection to the GM tube could be damaged. Please call for assistance. 1-800-293-5759 Move the unit away from possible source of electromagnetic or radio frequency radiation. Scan the Abacus with another unit to check for contamination. Yes. The unit will provide audio clicks and a settable hardware alarm for quick yes/no surveys. Yes. There is a flat head screw on one side of the hinge. To tighten the hinge, turn the screw clockwise. Data can be saved as a text "txt or as Comma Separated Values "csv". The report pulls the information associated with the listed owner of the Handheld device, however, on a PC, you enter the surveyor's name in the preferences under the utility menu. Ensure that the Bluetooth serial connection is set to un-secured. The unit can be affected by photosensitivity. Try removing the unit from direct sunlight.

CAN I USE THE ABACUS WHILE NOT CONNECTED TO A COMPUTER OR HANDHELD? CAN I CHANGE THE TENSION ON THE HINGE OF THE ABACUS? WHAT FORMAT DOES THE DATA LOGGER USE? HOW DO I CHANGE THE "SURVEYED BY" PORTION OFF THE REPORTS?

WHILE CONNECTING WITH A PC, I AM ABLE TO CONNECT, BUT THEN THE CONNECTION IS IMMEDIATELY LOST. WHAT ARE POSSIBLE CAUSES FOR THE UNIT HAVING A HIGH READING?

26

LIMITED WARRANTY WARRANTOR: S.E. International, Inc., P.O. Box 39, 436 Farm Road, Summertown, TN 384830039, USA, (931) 964-3561 ELEMENTS OF WARRANTY: S.E. International, Inc., warrants for 90 days the Geiger-Mueller tube and for one year all materials and craftsmanship in this product to be free from all defects with only the limitations set out below. WARRANTY DURATION: The warranty shall terminate and be of no further effect one year (90 days on the GM tube) after the original date of purchase of the product or at the time the product is: a) damaged or not maintained as is reasonable or necessary, b) modified, c) repaired by someone other than the warrantor for a defect or malfunction covered by this Warranty, d) contaminated with radioactive materials, or e) used in a manner or purpose for which the instrument was not intended or contrary to S.E. International, Inc.'s written instructions. This warranty does not apply to any product subjected to corrosive elements, misuse, abuse, or neglect. STATEMENT OF REMEDY: In the event that the product does not conform to the warranty at any time while this warranty is effective, the Warrantor will repair the defect and return the instrument to you prepaid, without charge for parts or labor. NOTE: While the product will be remedied under this warranty without charge, this warranty does not cover or provide for the reimbursement or payment of incidental or consequential damages arising from the use of or the inability to use this product. The liability of the company arising out of the supplying of this instrument, or its use, whether on warranties or otherwise, shall not in any case exceed the cost of correcting defects in the instrument, and after the said one year (90 days on the tube) period all such liability shall terminate. Any implied warranty is limited to the duration of the written warranty. PROCEDURE FOR OBTAINING PERFORMANCE OF WARRANTY: In the event that the product does not conform to this warranty, please write or call to the address above. S.E. International, Inc. will not accept contaminated instruments for calibration or repair under warranty or otherwise. NOTE: Before using this instrument, the user must determine the suitability of the product for his or her intended use. The user assumes all risk and liability connected with such use.

Repair and Calibrations available at S.E. International, Inc. P.O. Box 39, 436 Farm Rd. Summertown, TN 38483-0039 USA Phone: 931-964-3561 / 1-800-293-5759 Fax: 931-964-3564 [email protected]

27

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Microsoft Word - Abacus Manual-March21-2007.doc