ATOMLAB 100 DOSE CALIBRATOR - Biodex

06-037ATOMLAB 100 DOSE CALIBRATOR OPERATION AND SERVICE MANUAL VERSION 2.1
086-250 086-258
BIODEX Biodex Medical Systems, Inc.
20 Ramsay Road, Shirley, New York, 11967-4704, Tel: 800-224-6339 (Int’l 631-924-9000), Fax: 631-924-9241, Email: [email protected], www.biodex.com
This manual covers installation and operation of the following products:
#086-250 Atomlab 100 Dose Calibrator (115V) #086-258 Atomlab 100 Dose Calibrator (250V)
NOTE: Prior to making activity measurements after a preset Dial Value has been changed on ANY isotope selection key, all Atomlab model Dose Calibrators must be power cycled; i.e., the Dose Calibrator power switch must be turned OFF and then back ON. Failure to power cycle after changing any preset key may cause a measurement ERROR on any or all isotope keys.
ATOMLAB 100 DOSE CALIBRATOR
Atomlab Dose Calibrator Warranty
1. Instrumentation
A. This equipment and its accessories are warranted by BIODEX MEDICAL SYSTEMS, INC., against defects in materials and workmanship for a period of two years from the date of shipment from BIODEX MEDICAL SYSTEMS, INC. During the warranty period, BIODEX MEDICAL SYSTEMS, INC. will in its sole discretion, repair, recalibrate or replace the equipment found to have such defect, at no charge to the customer.
EXCEPT AS STATED ABOVE, THERE ARE NO WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OR MERCHANTABILITY OR FITNESS FOR USE. BIODEX DOES NOT ASSUME LIABILITY FOR INCIDENTAL, CONSEQUENTIAL OR INDIRECT DAMAGES INCLUDING LOSS OF USE, SALES, PROFITS OR BUSINESS INTERRUPTION.
B. This warranty does not apply if the product, as determined by BIODEX MEDICAL SYSTEMS, INC., is defective due to abuse, misuse, modification or service performed by other than a BIODEX MEDICAL SYSTEMS, INC. authorized repair and calibration facility. Misuse and abuse include, but are not limited to, subjecting limits and allowing the equipment to become contaminated by radioactive materials.
C. In order to obtain warranty repair service, the equipment must be returned freight prepaid to one of our facilities. The Return Authorization number (R.A. #) should be included, along with a statement of the problem. Equipment will be returned transportation prepaid.
2. Calibration
A. Instruments are warranted to be within their specified accuracy at the time of shipment. If a question arises and BIODEX MEDICAL SYSTEMS, INC. determines that the initial calibration is in error, the instrument will be recalibrated at no charge.
B. Mechanical products are warranted to meet written specifications and tolerances at the time of shipment.
C. The return policy is as stated in paragraph 1.C.
3. Warranty is non transferable.
4. Non-Warranty Service
A. Repairs and/or replacements not covered by this warranty may be performed by BIODEX MEDICAL SYSTEMS, INC. at a factory authorized service location. Estimates of repair charges may be requested, however, a charge for estimate preparation may apply if the repair is later not authorized by the customer.
B. The cost of transportation into and out of the service location will be the responsibility of of the customer.
Service Procedure
If you think you have a service problem, take the following action.
1. Check to see that the problem occurs more than once.
2. Check the instruction manual and operations procedure.
3. Check the instruction manual Trouble-shooting Guide.
If you still think you have a service problem, call BIODEX MEDICAL SYSTEMS, INC., Service Department at (800) 224-6339.
Keep yourself and the phone next to the equipment.
1. Service will ask you for a brief description of the problem. We will ask specific questions about the malfunction that occurred. This diagnostic process may take a few minutes, so call us when you have time to spare.
2. After taking the information, we will advise on the action we will take.
3. Sometimes service personnel must consult with engineering and it may take time to get back to you. Be sure to let the service representative know your schedule so that we can call at a convenient time.
4. The return call may be from a person other than whom you first reported the problem to.
5. After analyzing the problem, we will decide if the unit must be returned to us for repair, or replacement parts will be sent.
6. If unit must be returned, it will be given a return authorization (R.A. #) number by us. Pack the system in the carton that it was originally shipped in, or pack it safely and securely to avoid shipping damage. It is the customer's responsibility for any damage that occurs during shipping.
7. Non-warranty/non-service contract charges for repair are as follows: a. Materials
+ b. Time
c. Shipping Charges
ATOMLAB Dose Calibrator Operation Manual Packing Slip
PACKING SLIP
The Atomlab 100 Dose Calibrator (#086-250 or #086-258 with RS-232 port) and its respective components comes carefully packed in two cartons inside a large, single shipping box. The cartons, each marked with an appropriate serial number, are labeled:
• DISPLAY UNIT • DETECTOR UNIT
NOTE: Prior to removing any of the cartons from the shipping box, visually inspect the box and the inside packing for damage. If any damage is noted, do not unpack the contents. Notify the carrier immediately so that a claim can be made if necessary, and contact your Biodex Medical Systems Sales Representative. If there is no visible damage, remove the cartons and place them on a table or to the side. We suggest removing the DISPLAY UNIT carton first.
NOTE: Before deciding on a location to set up your Atomlab for operation, be sure to read Chapter Two on installation. This chapter notes operating and environmental requirements, and offers several tips on choosing a location for your dose calibrator.
In addition to the Display Unit itself, this carton contains the Atomlab's Operation Manual, all the necessary connection and power wires needed to run the system, and a Moly Assay Kit. A Report of Calibration can be found in the Instruction Manual's front, inside pocket.
CAUTION: The carton labeled DETECTOR UNIT is very heavy, ~32 pounds. Severe damage to the unit may result if this carton is dropped. Remove the detector from the carton and carefully place it on the table or other counter where you will set up and use your Atomlab unit. Make certain the table top will support a minimum of 300 pounds. We suggest that you place the carton on its side so that you can slide the Detector Unit out of the carton onto its base. Inserted into the Chamber Well should be a Chamber Well Liner. A Plastic Sample Holder is packed with the Display Unit.
Shipping Cartons:
Biodex Medical Systems I Release 2.0
ATTENTION: Le carton étiqueté UNITÉ DE DÉTECTION est très lourd, ~32 livres. Cet appareil peut subir de sérieux dommages s’ii est échappé. Retirez le détecteur de son carton et utiliserez le avec prudence sur la table ou le computoir où vous installerez et utiliserez l’unité Atomlab. Assurezvous que la table supportera un minimum de 300 livres. Nous suggérons que vous placiez le carton sur son côté afin que vous puissiez faire glisser L’UNITÉ DE DÉTECTION du carton à sa base. Dans la chambre du calibrateur vous devriez trouver un manchon protecteur. Un échantillon en plastique est emballé avec l’unité de présentation.
NOTE: Do not discard the packing materials, cartons or shipping boxes. You will need them should it become necessary to return any of the Atomlab components in the future.
Biodex Medical Systems II Release 2.0
Figure P-1: The Atomlab Dose Calibrator Major Components.
Biodex Medical Systems III Release 2.0
TABLE OF CONTENTS
Chapter Two: Installing Your Dose Calibrator ...............................................2-1 Describes what you need to properly use your Atomlab Dose Calibrator, powering up, installation, and cleaning instructions.
Chapter Three: Getting Started .......................................................................3-1 This chapter allows you to gain a quick familiarization of the operation of your Dose Calibrator.
Chapter Four: Description ...............................................................................4-1 Describes features and functions of your Dose Calibrator, including the Detector and Display units.
Chapter Five: Operation...................................................................................5-1 Describes the full operation of your Atomlab 100 Dose Calibrator
Appendix B
Appendix C
Decay Calculations .......................................................................................C-1
Appendix E Calibration Values for Version Six Firmware Other Isotope Selections........E-1 (Includes Setting Information for Y-90)
Appendix F Atomlab Dose Calibrator Calibration and Traceability ..................................F-1
Appendix G Atomlab Computer Interconnection ..............................................................G-1
Appendix H Electromagnetic Compatibility ......................................................................H-1
Appendix I Determining The Firmware Level of Your Dose Calibrator ............................I-1
Appendix J Quality Assurance Testing of Atomlab Dose Calibrators...............................J-1
Schematics
ATOMLAB Dose Calibrator Operation Manual Table of Contents
Biodex Medical Systems V Release 2.0
CHAPTER ONE: INTRODUCTION TO THE
IMPORTANT NOTES FOR ATOMlAb DOSE CAlIbRATOR USERS
The Atomlab Dose Calibrator you have purchased is a high- quality, dependable and reliable instrument. Before using it, please review the following points.
Before using this device, be certain to read the entire operation manual. Failure to read the manual may result in user error or inaccurate data.
The Atomlab Dose Calibrator should be used only as specified in the operation manual.
The Atomlab Dose Calibrator is designed for use in a patient environment.
Quality Assurance Testing of Atomlab Dose Calibrators is provided in Appendix J.
OVERVIEW
Biodex Medical Systems’ Atomlab 100 Dose Calibrators are designed to perform accurate radioisotope measurements simply and quickly. Due to our unique electronics and software, the performance you obtain when using these units will surpass the latest stringent regulatory performance standards.
By familiarizing yourself with the procedures presented in this manual, you will be able to carry out dose measurements while keeping your Atomlab 100 functioning optimally and reliably for years to come.
ATOMLAB Dose Calibrator Operation Manual Chapter 1
Biodex Medical Systems 1-1 Release 2.0
CONVENTIONS OF THIS MANUAL
The following conventions are used to provide graphic and other aids to facilitate following instructions given in this manual.
The Increment/Decrement keys are represented by ⇑ and ⇓.
Keys in Boldface Type (i.e., PRINT) must be pressed for a response.
When there is an option in a step, it will be represented by upper case brackets { }.
Key Labels
OVERVIEW
We strongly suggest that you read this chapter before mov- ing on to the operation chapter. This will help ensure that your Atomlab Dose Calibrator is up and running properly, and that you have adequate access to the unit to perform all the functions that will be discussed. It will also help you become familiar with the various components of your dose calibrator.
OPERATING REQUIREMENTS
Prior to installing your equipment, plan a layout for your Atomlab unit that will ensure it is convenient for measuring radionuclides and will not cause undue radiation exposure because of extra handling of high activity sources. There should be ample room to place a vial shield on the work surface (preferably behind an L-Block shield), open the shield and remove the vial using tongs, quickly place the vial into the Sample Holder and then place both into the Chamber Well.
Remember that to make radioisotope measurements you will have to place the clear plastic Chamber Well Liner into the Chamber Well and lower the plastic Sample Holder into the liner. Make sure there will be no obstructions, such as wall cabinets, above the Detector Unit. Such obstacles may make it difficult to insert and remove the Sample Holder.
Choose a table or other counter which is free of vibration, does not wobble, and will easily support 300 pounds.
The surface area of the table top should provide ample area to accommodate the Detector Unit, Display Unit, the Printer, the L-Block Shield, the shielded radionuclide preparation area, and room for writing. See Figure 2-1 for a typical dose preparation layout.
Work Surface
• 30 in. deep • 48 in. wide • 36 in. high
Figure 2-1: A typical dose preparation layout.
Frequently, dose calibrators are located in areas called hot labs in which there is a wet sink with plumbing. Do not locate your dose calibrator on a table or other counter which can become wet or is subject to splashing or spray- ing.
Avoid areas which have drafts caused by heating or air con- ditioners, or are in direct sunlight. Electronics work best when constant temperature is maintained.
The temperature range is from 0 to 40° C, and the relative humidity range from 0 to 95%.
Choose a location for your dose calibrator which is not frequently used by other personnel — one where the table on which it lies will not be bumped.
In general, make sure your work area is clean, dry, and dust free.
Physical Location and Environment
Avoid locating your dose calibrator near a radioactive materials storage area. The .25-inch lead shield around the detector shields it from changes in radiation levels from diagnostic energy radionuclides (i.e., Tc-99m); however, the high energy radiation from sources such as Cs-137 and Co- 60 will easily penetrate the shield and change the background radiation level. The lower the ambient radioactivity, the less background activity for which the Atomlab Dose Calibrator must compensate, and, the greater the accuracy and reliability of the readings.
POWER REQUIREMENTS
Choose a line power source with a socket which mates securely with the power plug provided.
Verify that the power line is properly grounded.
Do not choose an outlet that has a wall switch control.
100 to 120 VAC 1/2 A, or 200 to 240 VAC 1/4 A, selectable with Fuse Holder (see Appendix A).
50/60 Hz.
POSITIONING
After you have chosen a suitable location for your Atomlab Dose Calibrator and familiarized yourself with its components, position the various units. Make sure the Detector and Display Units have been positioned to where they will not have to be moved prior to connecting the cables.
CABLE CONNECTIONS
Refer to Figure 2-2 for an illustration of the Detector Unit's cable connector and rear panel. The Detector Cable is gray, ten feet long, and has white identical male connectors on both ends. The connectors are of a self-locking type.
Line Voltage
Line Frequency
Detector Unit Connection
1) Rotate the Detector Unit so that you can see the rectangular opening in one side of the base.
2) Take one end of the Detector Cable, orient its connector so that it matches the openings on the connector of the Detector Unit (refer to Figure 2-2), and then insert the connector firmly until you feel it click. Do not force the connector, it is self-locking! Gently pull on the connector to make sure it is firmly secured.
To remove the connector, squeeze both sides and pull.
3) Rotate the Detector Unit to its normal position so that the connector is facing away from the work area.
Figure 2-2: The Rear Panel of the Detector Unit, end of the Detector Cable, and the Operational Light.
NOTE: For the next procedure ensure your dose calibrator is turned OFF.
1) Rotate the Display Unit so that you are looking at the rear panel. Locate the connector labeled CHAMBER.
Display Unit Connection
2) Take the connector on the free end of the Detector Cable, orient it so that it matches the openings on the connector of the Display Unit, and then insert the connector firmly until you feel it click. Do not force the connector, it is self-locking! Gently pull on the connector to make sure it is firmly secured.
Figure 2-3: The rear panel of the Display Unit with Chamber Connector, the end of the Detector Cable, and the Display end of the Power Cord.
1) Rotate the Display Unit so that you are looking at the rear panel. Directly to the right of the connector labeled CHAMBER, locate the Fuse Holder. This is labeled USE ONLY WITH 250V FUSES, with 100-120 read upright, and 200-240 read upside down.
2) The orientation of the Fuse Holder determines the power your dose calibrator requires. When the label 100-120 and its corresponding arrow points to the arrow directly below the Fuse Holder, you can plug your unit into an 100 VAC power source.
Power Cord Connection
If, conversely, the label 200-240 and its corresponding arrow points to the arrow directly below the Fuse Holder, you must plug your unit into a 240 VAC power source.
NOTE: Your Atomlab 100 has already been configured for your use. If, however, you turn the Fuse Holder upside down to change the voltage required, the fuses within the Fuse Holder must have the proper rating. See Appendix A for details.
3) Locate the Power Switch to the right of the Fuse Holder and the socket for the Power Cable to the left.
4) Ensure the Power Switch is in the OFF position (0).
5) Plug the Power Cord into the socket.
6) Rotate the Display Unit back to its normal position.
7) Take the remaining end of the Power Cord and plug it into an outlet which meets the requirements previously outlined.
POWERING UP
Reach behind the Display Unit and power up your Atomlab by flipping the Power Switch from the 0 (OFF) position to the – (ON) position. The Self-Test will commence automatically.
Because the Atomlab 100 is capable of using multiple Chamber Units, the Self-Test for this system checks to see if more than one Chamber is in use. This causes the Self-Test to pause approximately 20 seconds after power up. To complete the test and place the unit in normal operating mode, press the ENTER key when it begins to flash.
If an error is detected on either system, it will be noted on the Electronic Thumbwheel Display. You can then refer to Appendix A or the Trouble-shooting Guide supplied with this manual to resolve the problem.
NOTE: After turning your Atomlab ON and completing the Self-Test or chamber selections, do not press any keys for at least an hour. This allows the sensitive electronics to stabilize.
PACKING MATERIAL
Now that you have set up your Atomlab Dose Calibrator, and everything is intact and functioning properly, take a few moments to repack the packing material. This material was esp e cially designed for safe shipment of the Atomlab Dose Cal i brator and should be considered part of the instrument. Place the shipping material in the appropriate boxes and put the boxes back into the shipping carton. Label the carton and store it in a safe, out-of-the-way location. If you ever need to return your dose calibrator for updates, calibration, or repair, use the original shipping carton, boxes, and shipping material.
GENERAL CLEANING INSTRUCTIONS As required, wipe down the exterior of the unit using a soft rag slightly dampened with alcohol.
CHAPTER THREE: GETTING STARTED WITH YOUR
OVERVIEW
This chapter provides a quick introduction to your Atomlab Dose Calibrator. It will familiarize you with the basic operation of making an Activity Measurement so that the instructions provided in the rest of the manual will make more sense. This chapter will be especially valuable to those of you who are already familiar with dose calibrator operation. A detailed description of the Display and Detector Units is provided in Chapter 4, and of operation procedures in Chapter 5. Also consult the Appendices for further information.
METHODOLOGY
An understanding of the following key functions, and a knowledge of the Atomlab Display Unit, will facilitate your use of the Atomlab Dose Calibrator.
Whenever you initiate a mode, such as Setup, the Atomlab Dose Calibrator will guide you by causing the LED's to flash on the keys you need to press.
When the manual specifies that a LED comes ON, it always means steadily, even if it was previously flashing. In some instances, pressing a key will cause a flashing LED to turn OFF or come ON steadily.
Refer to the Front Panel Display illustrated in Figure 3-1. On the Atomlab 100, the unlabeled key to the right of the ⇑⇓ on the Electronic Thumbwheel is referred to as the ENTER key. The 4-digit display associated with the Electronic Thumbwheel is referred to as the Electronic Thumbwheel Display. See Chapter 4 for details.
LED Keys
GETTING STARTED
If you have not done so already, reach behind the Display Unit and flip up the power switch from the left position (0) to the right (-) to power up your system. The TEST key LED will illuminate and the Atomlab will automatically initiate a Self-Test program.
For any Atomlab 100 Self-Test initiated by turning the unit ON, a pause occurs approximately 20 seconds after power- up. This allows the user to enter the number of Chamber Units connected to the Display. If you are using a single chamber, press the ENTER key when it begins to flash. The Self-Test will continue and, if no errors are detected, the Atomlab 100 will enter its normal operating mode. If you are using multiple chambers, refer to the Instruction Sheet provided with your Multi-Chamber Manual Interface for details on entering multiple chambers during the Self-Test.
Note that Atomlab 100 Self-Tests initiated by pressing the TEST key do not require the user to enter the number of Chamber Units connected. They automatically place the Atomlab in normal operating mode without a pause.
Any error detected during the Self-Test will show as an Error Message in the Activity Display. Refer to Appendix A for a description of Error Messages and the proper course of action.
Power-up
NOTE: The top right four-digit LED Activity Display always indicates activity in the Detector's Chamber Well, no matter which keys are pressed. (There are momentary exceptions: when you press the TEST key, for example.)
To the right of the Activity Display are the units of measure, e.g., microcuries (µCi). At this time, the display will indicate some numeric value and the µCi symbol. Also lit is a LED associated with one of the Isotope Selection keys. When an isotope is selected, the Atomlab Dose Calibrator is automatically calibrated to display the activity of that isotope. Press the Tc-99m (or any other Isotope Selection key) and observe the LED on the key come on (the Tc-99m key may already be selected). If there is no activity in the Detector, the displayed value should be about 1.00 µCi or less. This value may get lower after "warm-up".
NOTE: The Mo-99 key has a special function for the Moly Breakthrough test, which is described in Chapters 4 and 5.
NOTE: The activity reading when you first power up your dose calibrator may be any value, even negative, as you have not yet corrected for the background radiation in your work area. After you use the BKGND key as described below, and after the dose calibrator has warmed-up, the activity level should be close to zero (<0.1µCi).
Before activity measurements are normally made, a dose calibrator requires a background adjustment to assure there are no errors in the displayed value. The Atomlab Dose Calibrator automatically stores and subtracts the Background Value before displaying the activity reading.
With nothing in the Detector but the Chamber Well Liner and empty Sample Holder, press the BKGND key. The LED on the key will come ON while background measurements are made. The LED will go OFF automatically when completed and the displayed value should be less than 0.1 µCi. The activity value will remain in memory until the BKGND key is pressed again or the system is turned OFF.
Read the Display
Background Adjustment
NOTE: The normal functions of the dose calibrator are dis- abled as the background is compensated for. This procedure will take anywhere from several seconds to 100 seconds, depending upon the level of activity of previous measurements. You may abort the background measurement at any point by simply pressing the BKGND key a second time.
After the above background correction has been completed, remove your Cs-137 calibration Check Source from its shield, place it in the Sample Holder and lower it into the Chamber Well. Press the Cs-137 Isotope Selection key on the front panel and observe that the LED on the key comes on. The Activity Display will now indicate the activity of your Cs-137 Check Source. Compare it to the decayed calibrated activity (see Appendix C for Decayed Activity Chart, Chapter 5 for an explanation). For a properly calibrated source above 200 µCi, the displayed value should be within a few percent of the decayed calibrated value. If you do not have a Cs-137 source, use a calibrated vial Co-57 source and repeat the above by pressing the Co-57 key.
These calibration check sources provide a vital quality assurance test which should be done daily to assure proper performance of the calibrator.
AVERAGING PERIOD
The Atomlab 100 automatically selects the proper averaging period or time constant for the proper display of low activity sources. When you first lower the source into the well, the activity value quickly jumps to the final value. For a few seconds the value may fluctuate, but then the value settles down to a small variation in the right digit. The Atomlab Dose Calibrator will average the activity data while the source is in the Chamber Well, which over several seconds will result in a stable reading. As soon as the source is removed from the Chamber Well, the Activity Display will drop down to the near zero value.
Cs-137 Check
RANGE SELECTION
The Atomlab Dose Calibrator automatically selects the proper range to display the activity results (either mCi or µCi if you have selected Ci, or GBq or MBq if you have selected Bq). The selection is made on the basis of providing maximum resolution for the number displayed. Therefore, all you have to do is place the source in the Chamber Well and read the activity value from the Activity Display.
ISOTOPE SELECTION
Isotope selection can be done at any time before or after placing the source into the Chamber Well. As soon as you press an Isotope Selection key, the displayed activity value is corrected in accordance with the corresponding Calibration Value stored in memory.
DISPLAY UNITS
Proper units for radioactivity can be either the traditional Curie (Ci) or the international unit Becquerel (Bq), whichever may be required in your facility. Your Atomlab Dose Calibrator has the ability to display in either system by user selection through the SETUP key.
To change the Atomlab 100 Display Units, press the SETUP key and observe its LED come ON. This indicates the Atomlab 100 is in Setup mode. Observe that the unit indicator to the right of the Activity Display (for example, µCi) is blinking at the same rate as the LED on the OTHER key. Press the OTHER key and see that the other system of units (MBq) is now displayed and the displayed activity value has been corrected in accordance with this new system of units.
If you removed your Check Source, place it back into the Chamber Well. Toggle the units back and forth by pressing the OTHER key. Before leaving Setup mode, ensure that you have selected the proper system of units and then press the SETUP key again. This will lock the units selection into the display. The Activity Display units can be subsequently rese- lected in the Setup mode.
Changing Display Units
OVERVIEW
By this point, you should have already setup, installed and powered up your Atomlab 100 as described in Chapters 1, 2 and 3. Now, before getting into the actual operation procedures, we suggest you take a few minutes and review this chapter. It provides a complete description of the Display and Detector units comprising your dose calibrator. For an illustration of parts and components, refer back to "Packing Slip", Figure P-1.
GENERAL DESCRIPTION
The Atomlab Dose Calibrators are used to measure the radioactivity of a known radioisotope. Their primary applica- tion is the measurement of the dose administered to a patient in nuclear imaging. The design for both units incor- porates unique electronics and software which surpass stringent regulatory performance standards and provide fast and accurate results.
The Detector Unit uses an ionization chamber for radiation detection and an electrometer for ion current measurement. The chamber bias is generated with an electronic high voltage supply, eliminating the need for expensive battery changes. An optional Multi-Chamber Manual Interface is also available.
The Display Unit communicates with the Detector Unit through a serial port.
An optional RS-232 computer interface is available. This interface will allow the user to send data and commands between the dose calibrator and a remote PC. .
THE DETECTOR
The Atomlab Detector Unit is a well type ionization chamber capable of measuring activity as low as 0.01 µCi and as high as 9999. mCi of Tc-99m. The chamber is surrounded on all sides and on the bottom with .25-inch lead to both shield you from the source you are measuring and shield the dose calibrator from any ambient radiation.
THE CHAMBER
The well type chamber was carefully selected to provide a nearly "4 pi" measuring geometry which means that the radiation detector nearly surrounds the radionuclide. This allows the Atomlab Dose Calibrator to measure the activity of a sample no matter what its volume or shape, as long as it fits into the Chamber Well. This is necessary, for example, when measuring syringe doses when the volume is unim- portant.
CHAMBER WELL LINER
Placed within the well is a plastic liner to protect the chamber from contamination in the event of the source leaking during measurement.
CURRENT MEASUREMENT
The ionization current is measured by a microprocessor- controlled high impedance electrometer located within the base of the Detector Unit.
REAR PANEL
On the rear panel of the Detector Unit are the connectors for power and data communication with the Display Unit. The Detector Unit can be located up to three meters away from the Display Unit.
RESPONSE
The response of this type of ionization chamber has been carefully studied using radionuclides calibrated at the Na - tion al Institute of Standards & Technology. The result is a well-defined energy response curve which is used to determine the calibration values for many different isotopes with high accuracy. Each chamber has been calibrated with a Na tional Institute of Standards & Technology traceable source. The corresponding Calibration Value has been stored in the memory of the Detector Unit. After calibration, the chamber's accuracy is tested with several sources of dif- fering gamma energies whose activity values are traceable to the National Institute of Standards & Technology.
THE DISPLAY UNIT
The Atomlab Dose Calibrator Display Unit consists of control keys and displays that allow you to make activity measurements. A built-in microprocessor executes commands input via the front panel keys and computes activity values from Detector data.
The Display Unit, with a molded plastic case housing the electronics, has been specifically designed to perform Activity Measurements in a laboratory setting. To allow easy fingertip control of the keys, the front panel slopes gradually. The Activity Display slopes as well, providing an optimum viewing angle. On the rear panel of the unit are the power and communication connectors, and the power switch, which remain out of the way as they are infrequently needed.
ZERO CALIBRATION
The innovative design of the Atomlab's Dose Calibrator's electrometer ensures that this zero adjustment is performed while measurement of the activity values is being carried out, and is therefore continually updated.
The current from the chamber is collected on a capacitor in the feedback loop of the electrometer whose capacitance value is stable and measured to a high degree.
Method
Voltage measurements are made periodically. The time period between measurements is accurately calibrated. The second of two successive values is subtracted from the first by the microprocessor, which yields the net voltage change on the capacitor. Because the time interval between measurements is so small, any offset arising from fluctuations in the electronics is the same for both measurements, and is automatically compensated for during the subtraction.
DISPLAY UNITS
When you set your dose calibrator to display Activity Values in Ci (Curies), the conventional system of units, either µCi or mCi will be indicated next to the numeric display. The prefix micro or µ (10-6), or milli or m (10-3) is automatically selected by the system's microprocessor.
For example, if the numeric value displayed is 12.03, and µCi is indicated, the activity will be 12.03x10-6 Ci or 0.00001203 Curies; if 63.9 is displayed and mCi indicated, the activity is 63.9x10-3 Ci or 0.0639 Curies.
In the same manner, when you set the dose calibrator to the international system of units, Becquerels, either MBq or GBq will be indicated, where the prefix M represents Mega (106) and G represents Giga (109).
The absolute measurement range of the Atomlab Dose Calibrator is from 0.01 µCi to 9.999 Ci of Tc-99m (and the equivalent in Becquerels).
For example, 12.03 µCi = .445 MBq and 63.9 mCi = 2.36 GBq. If the numeric display reads 0.445 and MBq is indicated, the activity value is 445,000 Becquerels; if 2.36 is displayed and GBq indicated, the activity is 2,360,000,000 Becquerels.
THE DISPLAY UNIT-FRONT PANEL
To familiarize yourself with the location of the displays and various keys on the front panel, refer to Figure 4-1
The four-digit LEDs which make up the Activity Display always display measured activity, except during the Self-Test.
To the right of the Activity Display are the four display unit indicators: µCi, mCi, MBq, and GBq. If you select Ci as the display units, the LED behind either µCi or mCi will come ON, depending on the range automatically selected by the Atomlab Dose Calibrator; if you select Bq, MBq or GBq will be indicated.
NOTE: If the Detector Well is empty, the display units should be in the lower range, either µCi or MBq.
Figure 4-1: The Atomlab 100 Front Panel
These keys allow you to select which radioisotope you will be measuring. When, for example, you press the key marked Tc-99m, the dose calibrator will be calibrated to accurately measure the activity of Tc-99m. The LED on the key you press will come ON so that you will always know for which radioisotope the system is currently calibrated.
The standard radioisotope (Isotope Selection) keys for the Atomlab 100 include: Co-57, Cs-137, I-131, In-111, Ga-67, Xe-133, I-123, Tl-201, Mo-99 and Tc-99m.The Co-57 and Cs-137 keys are primarily used for accuracy and Constancy Tests while the Mo-99 key is used for the Moly Breakthrough Test.
Activity Display
Standard Isotopes
The keys labeled 1, 2 and OTHER allow you to display activity values for non-standard radioisotopes. The 1 and 2 keys are programmable, eliminating the need to constantly set the Calibration Values for any non-standard radioisotope you constantly measure, while the OTHER key allows you to set up the dose calibrator for a particular radioisotope at the time of measurement (its default setting can be modified as well).
NOTE: When you press any one of these keys, the Electronic Thumbwheel (#1) Display will show the associated Calibration Dial Value.
The Self-Test is initiated by turning the Atomlab ON, or by pressing the TEST key. The LED on the TEST key comes ON. Items tested include: elec trometer sensitivity, chamber bias supply, software check sum, and the display. All LED indicators are lit to let you know their condition. Dur ing the Self-Test, the Activity Display does not indicate activity.
The display test sequence is as follows.
1) All segments of the numeric LEDs or digits on the Ac - tivity Display, the decimal points, and all four Activity Display unit LED indicators, will come ON for four seconds. The display will look like:
8.8.8.8. µCi mCi MBq GBq
After 4 seconds, this display will turn OFF and the next test given in 2) will occur.
2) All Electronic Thumbwheel Display digits and decimal points will come ON. The display will read as follows:
8.8.8.8.
3) Press the flashing ENTER key. The LED indicator on every key will come ON.
When the Self-Test is completed and no faults have been detected, the LED on the TEST key turns OFF. At this point, the system is ready to use.
User-Defined Keys
Self-Test (TEST Key)
Display Test Sequence
If there should be a prob lem detected, the LED on the TEST key will flash and the Electronic Thumbwheel Display will show a number corresponding to the fault. See Appendix A or the Atomlab Dose Cal ibrator Trouble-shooting Guide for Error Messages and correction procedures. If you should decide to continue in spite of the fault, press the TEST key to return to normal operating mode. The LED on the TEST key will continue to flash. In the event of an error message, we recommend you perform a Constancy and Linearity Test before continuing.
When you press the BKGND key to store the background activity, this value remains in memory until you press the key again. Pressing the BKGND key a second time will abort the process.
NOTE: Even though both Atomlab Dose Calibrators compensate for background interference, the accuracy of Activity Measurements depends on the intensity of the background radiation. For this reason, store the new generator, storage generator and check sources away from the dose calibrator.
SETUP MODE
Pressing the SETUP key accesses the Setup mode. At this point you may change the dial value settings. To change other setup parameters once in Setup mode:
1) Press TEST one time to display the current firmware version.
2) Press TEST two times to display the current chamber version.
3) Press TEST three times to display the current chamber number.
4) Press TEST four times to display high voltage.
5) Press TEST five times to return to Setup mode.
Background Correction (BKGND Key)
CONTROL FUNCTION KEYS
There are four keys which perform specific functions: the keys labeled SETUP, TEST, and BKGND, and the unlabeled key, which on the Atomlab 100 is referred to as ENTER in this manual. In conjunction with the Electronic Thumbwheel (described below), these keys allow the user to perform such functions as selecting the Activity Display Units, calibrating the Isotope Selection keys, testing the instrument, and compensating for exterior conditions which affect the accuracy of the Atomlab 100.
ELECTRONIC THUMBWHEEL
The Electronic Thumbwheel consists of a 4-digit LED Display (Electronic Thumbwheel Display), ⇑⇓ keys, and the unlabeled key referred to in this manual as the ENTER key.
The Electronic Thumbwheel Display shows:
• Calibration Value when the 1, 2, and OTHER key has been selected, or when any of the other Isotope Selection keys have been selected in Setup mode.
• Error Numbers if the Self-Test has localized a fault. • Countdown for Moly Breakthrough Test.
An arrow pointing up is to the left of the Increment key (⇑), an arrow pointing down is to the right of the Decrement key (⇓). The Increment/Decrement keys, when pressed, change the value shown on the Electronic Thumbwheel Display cor- respondingly. If held, the speed at which the value changes will increase. The maximum value is 999; the minimum 0.1.
Electronic Thumb wheel Display
DOSE CALIBRATOR
NOTE: Most of the following functions and procedures are briefly described on the Quick Reference Chart provided with this manual.
At this point, make sure you have performed the steps de - scribed in Chapters 2 and 3 and are familiar with Chapter 4.
GENERAL OPERATING TIPS
The next few guidelines should be followed to ensure obtaining the most accurate, reliable results:
1) Perform the Self-Test, Daily Constancy, Quarterly Linearity and annual accuracy tests as required. If not properly compensated for, changes in operating parameters will affect the accuracy of readings.
2) Do not introduce other high energy radioactive sources near the location of the Atomlab 100. Try to maintain a stable environment.
3) Leave your Dose Calibrator ON at all times, or make sure you turn it ON at least one hour prior to using it.
CAUTION: Keep the Chamber Well Liner in the Detector at all times. Failure to do so will affect the accuracy of test results obtained and leave open the possibility of con- taminating the Chamber Well.
ATTENTION: Gardez le manchon protecteur à l’intérieur de la chambre du calibrateur en tous temps. A défaut de cette précaution, la précision des résultats de vos tests peut être affectée et, laisse place à la possibilité de contaminer le puits de la chambre.
DAILY CHECKS
Perform the following steps daily if radioisotope activity measurements are to be taken.
The Self-Test is automatically initiated at power-up. Because the Atomlab 100 is capable of using multiple chamber units, the Self-Test on this system checks to see if more than one chamber is in use. This results in approximately a 20-second delay from power-up to the start of the test. If only one chamber is connected to the display unit the Self-Test will automatically resume and, providing no errors are detected, the unit will advance to its normal operating mode. If any faults are detected, refer to Ap pen dix A or the Atomlab Dose Calibrator Trouble-shooting Guide.
If two or more chambers are connected to your Atomlab 100, the system must be programmed to initialize each chamber as explained in the following procedure.
1) With the Atomlab turned OFF, turn the switch box dial to chamber one.
2) Reach behind the display unit and flip the Power Switch to the ON position. Allow the unit to complete the standard Self-Test.
3) Press SETUP. The SETUP LED should come ON.
4) Press TEST three times in succession. The message CH- 1 will be displayed in the Electronic Thumbwheel display.
5) Using the ETD ⇑ and ⇓ arrow keys, enter the total number of chambers connected to the display.
6)Press TEST twice.
7) Press SETUP. The system should now be in standard operating mode. The SETUP LED should be OFF.
8) Turn the switch box dial to the next chamber (#2) and repeat steps three through seven. Do this for each chamber connected to the display.
Self-Test
Self-Test (Multiple Chambers)
9) To ensure that each chamber is set correctly, repeat again steps three through seven for each switch box chamber setting. For each switch box setting the ETD should indicate the total number of chambers connected to the display unit.
10) Turn the Atomlab OFF.
11) Set the switch box to chamber one and turn the system back ON. After approximately 20 seconds the display unit will emit a “beep,” the ENTER key will begin to flash and the prompt “CH-1” will again appear in the ETD.
12) Press the flashing ENTER key and allow the Self-Test to proceed. When the Self-Test is complete chamber one will be fully initialized.
13) Set the switch box to chamber two. Turn the Atomlab OFF. Wait five seconds and turn it back ON.
14) At the “beep” use the ETD ⇑ and ⇓ arrow keys to increment the ETD value so that it matches the switch box setting.
15) Press the flashing ENTER key and allow the Self-Test to proceed. When the Self-Test is complete the chamber will be fully initialized.
16) Turn the Atomlab OFF. Set the switch box dial to the next chamber and turn the system back ON. Repeat steps 14 to 16 for each additional chamber.
Ensure the Chamber Well Liner and Sample Holder have been placed into the Chamber Well. Press BKGND.
NOTE: Both the Chamber Well Liner and Sample Holder should be periodically checked for contamination as described later in this chapter (the more your dose calibrator is in use, the greater the frequency of checks required).
Remove your Cs-137 check source from its shield and place it into the Sample Holder. Lower the holder, with source, into the Chamber Well.
Press the Cs-137 key. The Activity Display will now show the activity of your Cs-137 check source.
Background Correction
Constancy Check Cs-137
Compare the displayed activity with the decayed calibrated activity (for an example of how to calculate a decayed activity see "Isotope Selection Key Calibration", later in this chapter). For a properly calibrated source above 100 µCi, the displayed value should be within a few percent of the decayed calibrated value.
NOTE: If you do not have a Cs-137 source, use a calibrated Co-57 source and press the Co-57 key to perform the above steps.
STANDARD ACTIVITY MEASUREMENT
The following procedure allows you to make a typical Activity Measurement with your Atomlab 100.
1) Place the radioisotope to be measured into the Sample Holder and carefully lower it into the Chamber Well.
2) Press the Isotope Selection key corresponding to the isotope to be measured.
3) The Activity Display should now show the activity of the selected isotope.
MOLY BREAKTHROUGH TEST
A Moly Breakthrough test is an evaluation of the amount of Mo-99 contamination in a vial or syringe of Tc-99m. Tc-99m, a decay product of Mo-99, is obtained from a generator by leaching it from the column of Mo-99 after it is formed.
The test method has been derived from the fact when Mo-99 decays, high energy gamma photons (~750 keV) are produced which can "breakthrough" a lead wall with a thickness sufficient to totally absorb the lower energy Tc-99m gamma. Therefore, when a Tc-99m source is placed in a properly shielded lead container and inserted into the Chamber Well of the Atomlab 100, any measured radiation will be due to Mo-99 gamma transmission.
NOTE: The Mo-99 key has been calibrated to measure the activity of Mo-99 in a source contained within the optional Moly Breakthru Shield. You must use this breakthrough shield. Failure to do so may result in inaccurate results. The Activity Display will show a direct readout of the activity, which means that corrections for wall absorption have been included in the Calibration Value.
Perform the following steps to carry out the Moly Breakthrough test.
1) Insert empty Moly Shield and press the Mo-99 key. The Electronic Thumbwheel Display will begin a 30-second countdown.
2) Once the countdown is finished, verify that the Activity Display reads 0.05 µCi or less. Wait about 30 seconds more for the Atomlab 100 to stabilize. If the value is too high, press the BKGND key. You may continue when the BKGND LED indicator goes OFF.
3) Place the Tc-99m source in the Moly Shield and carefully lower it into the Chamber Well.
4) Again press the Mo-99 key. The Electronic Thumbwheel Display will begin another 30-second countdown.
5) After the count reaches 0, the Activity Display should be stable enough for an accurate Mo-99 activity reading.
NOTE: Although the Mo-99 countdown is intended to suggest an adequate time frame, the Atomlab 100 will continue to acquire Mo-99 data as long as the Mo-99 key is selected. As a general rule, the longer you wait, the more stable the reading.
Procedure
ISOTOPE SELECTION KEY CALIBRATION
If you have an isotope whose activity has already been accu rate ly calibrated, such as a source obtained from the Nation al In stitute of Standards & Technology, you may use it to set a Cal ibration Value for any of the Standard Isotope Selection keys. The procedure is as follows.
1) Obtain the calibrated activity and its date.
For example, the National Institute of Standards & Tech nol ogy source you obtained is I-125 with the following properties:
Activity measured: 12/13/88, 12:00 EST Activity per unit mass: 1.195 MBq/g ±0.005 (±0.5%) Mass: 4.95863 g
The half-life is 59.6 days ±0.2
Let A = current activity Ao = activity at time of calibration
A = Aoe – In(2)(t/T1/2)
where t = time lapse since calibration and T1/2 = half life
Ao = (1.195 MBq/g)(4.95863 g) = 5.926 MBq = 160.2 µCi
t = 60.25 days A = 160.2 e – In(2)(60.25/59.6)
= 79.5 µCi (2.94 MBq)
2) Insert the source with Sample Holder into the Well.
3) Press any standard Isotope Selection Key. The current Calibrated Value for the key will show in the Electronic Thumbwheel Display. If you are calibrating for an isotope not listed on the front panel, select the 1 or 2 key.
4) Use the ⇑⇓ keys to change the setting on the Electronic Thumbwheel Display so that the Activity Display shows the current activity of the sample which was calculated in step 1. The ENTER LED starts flashing.
NOTE: Because the calibration factors have a finite number of steps (i.e., the calculated value for activity may lead you to try and put in 7.345 when the calibration factor can only be 7.3 or 7.4). You may not be able to perfectly match the calculated value for activity. In other words, you may have to round the number.
5) Press the ENTER key. The Selected Isotope key is now programmed with the Calibration Value on the Electronic Thumbwheel Display. The ENTER LED turns OFF.
6) Press the SETUP key. The SETUP LED turns OFF to indicate the Atomlab 100 is out of Setup mode.
NOTE: Should you find that you never use one or more of the standard Isotope Selection keys, you may use the procedure above to reset them for a radioisotope you do frequently measure. However, you must identify or mark the key with the isotope for which it is programmed.
SETTING OTHER ISOTOPE VALUES
The following procedure allows you to measure the activity of a radioisotope not included among the ten standard preset keys. The calibration values you set for the keys labeled OTHER, 1 and 2 are programmed into memory, eliminating the need to reset the keys later (unless you need to measure a different non-standard isotope).
NOTE: In order to change the default Calibration Value for the other key you must select this key prior to initiating the Setup mode.
OTHER, 1 or 2 Key Calibration
NOTE: When you press one of the User Defined Isotope Selection keys (the OTHER, 1 and 2 keys), the Calibration Value for the selected key will always appear on the Electronic Thumbwheel Display. The only time the Calibration Value for the other Isotope Selection keys will appear on the Electronic Thumbwheel is when the Atomlab 100 is in Setup mode.
1) Press the SETUP key. The SETUP LED comes ON. The OTHER key LED begins to flash indicating you may select the OTHER display units if desired.
2) Press the key labeled 1 (or 2). The 1 (or 2) LED comes ON.
3) Select the Calibration Value from Appendix E corresponding to the radioisotope you intend to measure.
4) Use the ⇑⇓ keys to set the Calibration Value on the Electronic Thumbwheel Display. The ENTER LED starts flashing.
5) Press the ENTER key. The 1 (or 2) key is now programmed and will retain the Calibration Value you set it to, even if you turn OFF your Atomlab 100.
6) Press the SETUP key. The Atomlab 100 is now out of Setup mode.
Should you need to return the standard Isotope Selection keys (labeled Co-57, Cs-137, ... , Tc–99m) to their original preset Calibration Values, follow the above steps, but with the following changes:
• For step 2) press the standard Isotope Selection key in question.
• For step 3) look up the preset calibration dial value in Appendix D.
The Standard Keys
From time to time you may wish to check the Calibration Values of the standard Isotope Selection keys. With Appendix D before you, press SETUP and then press the standard Isotope Selection keys, comparing the settings on the Electronic Thumbwheel Display with values in the appendix. Pressing SETUP again takes you out of Setup mode.
CONTAMINATION CHECKS
To ensure that your Sample Holder is not contaminated, perform the following steps.
1) Remove the Sample Holder from the Detector.
2) Ensure that the Activity Display reads less than ±0.05 µCi or (MBq). If not, use the BKGND key to correct for the change in background radiation.
3) Place the Sample Holder into the Chamber Well.
4) Press the Mo-99 key. If, after the 30-second countdown on the Electronic Thumbwheel Display, the activity is >2µCi, set the sample holder aside. Repeat the test {steps 1) through 3)} the next day or after a weekend. If, after the repeat test, the activity is still >2µCi or greater, you need to order a replacement Sample Holder because of contamination.
5) If the activity is < 2µCi, place the Sample Holder back in the Chamber Well and, if the activity value now reads greater than 0.05 µCi, again press the BKGND key.
Repeat the above procedure, but only remove and replace the Well Liner.
Checking the Standard Keys
GLOSSARY
OVERVIEW
This glossary provides definitions for the most common terms relevant to the Atomlab Dose Calibrators.
The test of a dose calibrator to see how close the displayed activity values are to the true values.
The time the Atomlab takes to display a stable activity reading.
The function of the Atomlab, initiated by pressing the BKGND key, which stores a value for the ambient activity. This value is automatically subtracted from all subsequent activity measurements to compensate for the background activity level.
The international unit of activity, corresponding to one dps (disintegration per second, or one nucleus decaying per second). The Atomlab displays activity values in units of MBq (million Bq) or GBq (billion Bq).
The use of calibrated activity sources traceable to the National Institute of Standards & Technology to calibrate each Atomlab unit and verify the accuracy of the activity values it displays.
The value set on the Electronic Thumbwheel (#1) Display to adjust the Atomlab to correctly respond to a particular radioisotope. See Response, Ionization Chamber.
A sleeve shield package to perform linearity tests on dose calibrators.
Performing daily checks using a radioisotope with a long half-life to ensure that the activity values a dose calibrator displays is stable over a long period of time.
A chart projecting how the activity of a source will decay over a period of time at specified time intervals.
ATOMLAB Dose Calibrator Operation Manual Glossary
Biodex Medical Systems GL-1 Release 2.0
Accuracy Tests
Averaging Period
Background Correction
Becquerel (Bq)
An Atomlab component housing the ionization chamber detector and the electrometer.
Displayed value changes without the removal or insertion of a source in the Chamber Well.
The Atomlab component incorporating the electronics, control keys and displays which perform and show activity measurements.
The verification of the activity of a radiopharmaceutical to be administered to a patient, corresponding to the radiation to be delivered to the body.
Measures the current in the ionization chamber, which is proportional to the activity of a source within the chamber.
The section of the Atomlab Front Panel consisting of a 4- digit display, Increment/Decrement keys (⇑ and ⇓) and an associated key, which allows the operator to enter any number possible on the display into the Atomlab program.
The test of a dose calibrator to determine the variation in the displayed activity values due to the geometric configura- tion of the source's container (vial, syringe, etc.) and its location within the ionization chamber detector.
A device which responds to the activity of a source by form- ing ion pairs which can be collected as a measure of the radioactivity.
A calibrated solution containing a compound labeled with a radionuclide such as Tc-99m (radiopharmaceuticals). From such kits doses are prepared to administer to patients to facilitate nuclear imaging.
A partially transparent radiation shield behind which doses can be prepared.
The test of a dose calibrator to determine the variation in the displayed activity values from the true ones over the measurement range of the instrument.
Detector Unit
Display Fluctuations
Display Unit
Dose Calibration
L-Block Shield
Linearity Tests
A sleeve shield package to perform linearity tests on dose calibrators.
Used in the Moly Breakthrough Test to shield the radiation of the Tc-99m in an eluent so that the activity of the Mo-99 can be measured.
Used to determine the percentage of parent Mo-99 remaining in the eluent containing the daughter Tc-99m radionuclide.
The parent radionuclide which decays into the daughter Tc- 99m, used to generate radiopharmaceuticals.
National Institute of Standards & Technology, whose activities include maintaining radioactive material standards.
Nuclear Regulatory Commission, which is the agency of the Federal Government which regulates radioactive materials.
The Atomlab unit automatically selects which range of Display units (µCi or mCi, or MBq or GBq) to be used for the Activity Display to show activity values with the most sig- nificant number of digits.
The variation of the ion current collected by an ionization cham ber because of individual decay processes associated with different radioisotopes. Calibration Values are required to adjust the output of the electrometer for each radioisotope to compensate for this variation in response, thereby ensuring accuracy over the entire range of commonly used radioisotopes.
A method of performing linearity tests on a dose calibrator by encircling a single source with leaded sleeves of varying thickness, thereby reducing the activity the dose calibrator measures by a known amount. Comparison of the expected and actual activity values constitutes the test of linearity.
Lineator
Sleeve Shield
A method of performing linearity tests on a dose calibrator by measuring the initial activity of a source, accurately cal- culating its decayed activity at prescribed time intervals, and making activity measurements at those time intervals. Comparison of the calculated and actual activity values constitutes the test of linearity.
Refers to using sources for calibrating a dose calibrator whose activities can be traced to the National Institute of Standards & Technology.
Compensating for electronic drifts in the input and output of the electrometer of a dose calibrator so that they do not affect the accuracy of the displayed activity. The Atomlab's electrometer does this automatically by constantly subtract- ing the first of two successive activity measurements from the second, so that any offset is compensated for.
Source Decay
PROCEDURES
OVERVIEW
Should it appear that your Atomlab Dose Calibrator is not functioning properly, the procedures explained in this appendix, and on the Quick Reference Chart provided with this manual, should allow you to determine whether a problem does indeed exist and what steps can be taken to correct the difficulty.
Should you encounter any of the problems discussed in the following sections, immediately perform the accompanying steps to ascertain whether your dose calibrator requires servicing. If you conclude that it does, contact the Biodex Customer Service Department at 1-800-224-6339 for further instructions.
This appendix assumes that you have performed all the basic installation procedures presented in Chapter 2.
PROBLEM DESCRIPTIONS
The following problems are described in this appendix.
• System will not Power Up • Fluctuations in Activity Measurement • Unexpected Readings • Determining the current Software Version • Display Unit Fuse Inspection and Replacement • Setting Up the Atomlab to accept 100 VAC or 240 VAC • Important Notes about System Errors
SYSTEM WILL NOT POWER UP
If your Atomlab Dose Calibrator fails to power up, perform the following steps, proceeding to the next step only if the current one fails to remedy the problem:
ATOMLAB Dose Calibrator Operation Manual Appendix A
Biodex Medical Systems A-1 Release 2.0
1) Turn the Power Switch OFF for several seconds, then switch it back ON.
2) Turn the power OFF again and remove the Power Cord from the electrical outlet. Remove the other end of the Power Cord from the receptacle on the rear of the Display Unit.
3) Re-insert the Power Cord into the receptacle and then plug the Power Cord back into the outlet. Turn the power back ON.
4) Turn the power OFF, remove the Power Cord from the outlet and verify that the voltage of the outlet is correct. If not, repair the outlet or find another outlet that provides the required voltage. Re-insert the Power Cord and turn the power back ON.
5) Turn the power OFF, remove the Power Cord from the outlet and remove the Fuse Holder, as described later in this appendix (see Figure A-1). Verify that both fuses are intact. If one or both are not, replace. Re-insert the Fuse Holder into the rear panel of the Display Unit. Re-insert the Power Cord into the outlet and turn the power back ON.
If your system still will not power up, call the Biodex Customer Service Department.
FLUCTUATIONS IN ACTIVITY MEASUREMENT
When the system is displaying activity for the more common isotopes, the electrometer continually averages the data it receives from the detector. This ensures, for most readings, a stable Activity Display.
After you insert an isotope into the Detector and select the properly calibrated key, the display may vary at low activity values as the system acquires the new data. After a short time the Activity Display will stabilize, with expected fluctuations described below. If the display continues to fluctuate, and you have verified it is not because of a high Calibration Value, consult Biodex Customer Service Department.
Procedure
For some isotopes which require a high Calibration Value, you may observe fluctuations of ±0.5 µCi or more. Keep in mind that the Calibration Value for an Isotope is related to gain of the electrometer, or by what factor the electrometer has to amplify the signal from the detector. The Calibration for Tc-99m is 33.6, and a reading of 10 µCi for Tc-99m is equivalent to 10-12 Amps measured by the electrometer. High Calibration Values impact gains so that the electrometer amplifies inherent noise to a greater degree. Thus, greater fluctuations are observed in the Activity Display.
For instance, the Calibration Value for Co-60 is 5.0. The fluctuation due to noise probably would not be noticeable (±0.01 µCi). The fluctuation due to noise for Tc-99m (33.6) is approximately ±0.05 µCi. For an isotope requiring a Calibration Value of 500 (for P-32 it is 632) the fluctuation will be ±0.5 µCi or more.
The Atomlab Dose Calibrator begins averaging display data the moment you press the Mo-99 key (Calibration Value =180). This means that at first the fluctuations will seem relatively high before gradually decreasing. This is why the Atomlab Dose Calibrator provides the 30-second countdown. In addition, the relatively high Calibration Value means the fluctuation due to inherent noise will be slightly higher than for the other common isotopes. Again, these fluctuations are to be expected and do not require any action on your part.
UNEXPECTED READINGS
If for some reason you suspect that the reading on the Activity Display is inaccurate, ensure that the Calibration Value for the proper Isotope Selection key is correct.
DETERMINING THE CURRENT SOFTWARE VERSION
To verify the current Atomlab 100 Display Unit firmware level:
1) Press SETUP.
2) Press TEST. The Display Unit software level will appear on the ETD (#1) window.
Display Fluctua - tions For High Calibration Values
Mo-99 Fluctuations
3) Press TEST twice more to return the system to normal operating mode.
DISPLAY UNIT FUSE INSPECTION AND REPLACEMENT
The following section provides the procedure to remove the Fuse Holder. Refer to Figure 2-3, which shows the rear panel of the Atomlab Display Unit, and Figure A-1, which illustrates the actual Fuse Holder replacement procedure.
CAUTION: Due to the possibility of electrical shock, danger of injury to yourself, and damage to the equipment, does exist. Be sure to switch the power OFF, and unplug the unit, before proceeding.
ATTENTION: Due à la possibilité de choc électrique, il existe un danger de vous blesser ou de causer des dommages à l’équipement. Assurez-vous de bien fermer l’appareil et de le débrancher avant de procéder.
1) Rotate the Display Unit so that you are looking at the rear panel. Directly to the right of the connector labeled CHAMBER (between the power plug and ON/OFF switch), locate the Fuse Holder. This is labeled in the center with USE ONLY WITH 250V FUSES, on the bottom with100V-120V read upright and on the top with 200V-240V read upside down.
2) The orientation of the Fuse Holder determines the Orientation power the Atomlab unit requires. If the label 100V-120V can be read upright (the label 200V-240V is upside down), and the corresponding arrow directly below the label points to the arrow on the rear panel directly below the Fuse Holder, then you must plug your dose calibrator into an 100 VAC power source.
If, conversely, the label 200-240 can be read upright (the label 100V-120V is upside down), and the corresponding arrow directly below the label points to the arrow on the rear panel directly below the Fuse Holder, then you must plug your dose calibrator into a 200 VAC power source.
Procedure
3) There is a small indentation to the left of the Fuse Holder. Insert the end of a flat-edged screwdriver into the indentation and gently pry the Fuse Holder out slightly. Now, use your fingers to pull the Fuse Holder out of the panel.
Once the Fuse Holder is removed, inspect the filament at the center of the two fuses. If it is burned or broken in any way the fuse must be replaced. If the filament does not appear to be broken or burned, test the fuse for continuity with an ohm meter.
Figure A-1: Removing the Fuse Holder
Fuse Inspection
100-120 VAC Two SLO-BLO 5x20 mm 1/2 Amp
200-240 VAC Two SLO-BLO 5x20 mm 1/4 Amp
CAUTION: The danger of damage to the equipment exists. Be sure you properly orient the Fuse Holder prior to replacing it.
ATTENTION: Danger de dommage à l’ équipement. Assurez-vous de bien orienter le support de fusibles acant de le remplacer.
To replace the Fuse Holder, position it into the indentation from which it was removed and gently push it back into place. It is critical to first determine the particular power requirement (100 VAC or 240 VAC) and ensure the Fuse Holder is properly oriented before turning the system back ON. See step 2), above.
SETTING UP FOR 100 VAC OR 240 VAC
Figure 2-3 shows the proper orientation of the Fuse Holder to set up your Dose Calibrator for 100 VAC operation. The Fuse Holder contains two 1/2 Amp, 250 VAC fuses.
If you should wish to set up your system to accept 240 VAC, remove the Fuse Holder, as described above, replace the existing fuses with 1/4 Amp, 250 VAC fuses, and then replace the Fuse Holder with the proper orientation.
IMPORTANT NOTES ABOUT SYSTEM ERRORS
Following the Self-Test, if a fault has been detected the TEST LED will remain on and the Electronic Thumbwheel Display (#1) will show the first error message in the Form "Er.1, Er.2", etc. Each time you press the TEST key the next Error Message, if further faults have been detected, will be displayed. The TEST LED will flash continuously to inform you that more errors have been detected.
Fuse Replacement
Fuse Holder Replacement
After you have reached the last error message, press the TEST key once more. If one or more of the Error Messages still persist, refer to Appendix A or the Atomlab Dose Calibrator Trouble-shooting Guide provided with this manual.
NOTE: In some instances an electronics glitch will cause an error to be displayed, even though there is no problem with your dose calibrator. For this reason, be sure to run the Self-Test a second time if an initial review of the problem indicates no fault exists.
NOTE: For certain error fault you can press the TEST key and continue to use your dose calibrator. The LED on the TEST key will continue to flash, reminding you that action to correct the problem must eventually be taken. Some of these faults can be easily corrected over the phone by the Biodex Customer Service Department. Other faults, however, require that you return the dose calibrator to Biodex Medical Systems for servicing.
CAUTION: Only qualified service personnel should remove the chamber cover. There is an electrical shock hazard. Components under cover operate at 350 volts. The chamber bias supply capacitors require at least two weeks, with power disconnected, to discharge to less than 50 volts.
ATTENTION: On ne doit confier qu'à un personnel d'entre- tien qualifié le soin de déposer le couvercle de la chambre d'ionisation. Il y risque de danger électronique. Les com- posants sous le couvercle fonctionnent sous une tension d'environ 350 V. La chambre d'ionisation est dotée de con- densateurs qui nécessitent au moins deux semaines d'ali- mentation débranchée pour se décharger à moins de 50 V.
Chamber Service
APPENDIX B Atomlab 100 Dose Calibrator Specifications
OVERVIEW This appendix provides the physical and operating specifications of your Atomlab 100 Dose Calibrator.
MEASUREMENT RANGE For Tc-99m, 0.01 µCi to 9999 mCi, auto-ranging.
DISPLAY RANGES Units are user selectable:
Ci Bq
00.01-19.99 µCi .001-1.999 MBq 20.0-199.9 µCi 2.00-19.99 MBq 200.-1999. µCi 20.0-199.9 MBq 2.00-19.99 mCi .200-1.999 GBq 20.0-199.9 mCi 2.00-19.99 GBq 200.0-9999. mCi 20.0-399.9 GBq
RESPONSE TIME Auto selection:
one second above 2 mCi; three seconds between 200 µCi and 2 mCi; three to 30 seconds below 200 µCi.
ACCURACY Overall accuracy of activity determination for specific front panel isotopes using the factory set Calibration Values is within 3% or 0.3 µCi, whichever is greater.
NOTE: Intercomparison of calibrated sources and the Atomlab 100 requires combining the uncertainties of both the Atomlab 100 and the calibrated source to determine expected agreement.
ATOMLAB Dose Calibrator Operation Manual Appendix B
Biodex Medical Systems B-1 Release 2.0
Within 1% or 0.2 µCi, whichever is greater.
Short term (24 hours): within 0.3% above one mCi, exclusive of background.
Long term (one year): within 1%.
NOISE
Display Fluctuations Activity Range
< 1 Digit > 199.9 µCi < ±2 > 19.99 µCi < ±4 0.01 to 19.99 µCi
ENERGY RANGE 25 keV to 3 MeV
ISOTOPE SELECTION Ten preset Keys: Co-57, Cs-137, I-131, In-111, Ga- 67, Xe-133, I-123, Tl-201, Mo-99, and Tc-99m.
Two user programmable keys: 1 and 2.
OTHER key for setting on-the-spot Calibration Values for non-standard isotopes.
CALIBRATION VALUE DISPLAY Four digit Calibration Value Display with Increment/Decrement keys to change value. Range is from 000.1 to 999.
Detector Linearity
Electrometer Linearity
Electrometer Accuracy
DETECTOR TYPE Well-type pressurized ionization chamber, with Argon filled gas. Replaceable plastic liner included. Dimensions are:
Well opening: 2.5 in. (6.4 cm) Well depth: 10.25 in. (26 cm)
.25 in. (6 mm) lead surrounding ionization chamber, with top well opening.
300 volt electronic power supply.
ENVIRONMENTAL OPERATING CONDITIONS Temperature: 0 to 40°C Humidity: 0 to 95% rh, non-condensing
For optimum performance, the Atomlab 100 should be oper- ated in a normal laboratory environment where the temperature and humidity are maintained for normal human comfort and the ambient radiation level is low and constant.
PHYSICAL DATA
Display Unit Detector Unit
Size: 3.75 x 12 x 14.3" 7.5 x 7.5 x 16.25" (9.5 x 30.5 x 36.3 cm) (19 x 19 x 41.3 cm)
Weight: 6 lb (2.72 kg) 35 lb (15.9 kg)
POWER 100 to 120 VAC 1/2 A, or 200 to 240 VAC 1/4 A, selectable with fuse card.
50/60 Hz Detachable line cord. Built-in EMI filter and transient sup- pression.
Detector Shield
Chamber Bias
Line Voltage
Line Frequency
DETECTOR CABLE 10 ft. (3.1 m)
Six total: two for power, one for chassis ground, three for serial data.
AMP Mate-n-Lock, white with hooded strain relief.
FRONT PANEL Four digit, seven segment red LED, 0.57 in. (14.5 mm) high, four floating decimal point indicators between digits.
Four discrete inscriptions back lit with large red LEDs: mCi, µCi, MBq or GBq (right adjacent to digits).
Momentary contact, rubber with conductive pad.
Adjacent red LED to indicate selection.
I-131, In-111, Ga-67, Xe-133, I-123, Tl-201, and Tc-99m.
Each key has a pre-assigned Calibration Value for activity measurements in a standard syringe or vial form.
Keys can be reset for new Calibration Values.
The Mo-99 key is calibrated for Mo-99 assay in a shielded vial of Tc-99m. The Atomlab 100 provides a 30-second countdown.
Co-57 and Cs-137: used for accuracy and constancy checks.
OTHER, 1, and 2: allows activity display of other isotopes. In Setup mode the OTHER key selects units.
Four digit, seven segment red LED, 0.27 in. (6.9 mm) high, with colon between second and third digits, and three floating LED decimal point indicators between digits.
Length
Conductors
Connectors
Two round Increment/Decrement keys below display. When an Increment/Decrement key is depressed momentarily, the Display changes accordingly by one digit.
If the key is held down, the Display changes slowly at first (1 digit per 1/4 second), then more quickly after two-and- one-half seconds (ten digits per 1/4 second), after which the display will change full range in about seven seconds.
Displays Calibration Value when OTHER, 1 or 2, has been selected;
Error Number when ER. is lit.
Calibration Value of pre-selected isotope when in Setup mode (000.1-99.).
The ENTER key (to the right of the Electronic Thumbwheel Display) programs the Calibration Value to correspond with the selected isotope key.
The SETUP key allows the selection of activity display units and the calibration of all of the isotope Selection keys. To enter Setup mode, press the key once. Pressing the key a second time takes the Atomlab 100 out of Setup mode.
The TEST key enables the Dose Calibrator’s Self-Test program, which includes a test of the electrometer sensitivity, chamber bias supply, software checksum, and the display.
The BKGND key enables the background radiation measurement for storage and automatic correction.
100 to 120 VAC 1/2 A, or 200 to 240 VAC 1/4 A, selectable with Fuse Holder (See Appendix A).
Electrical Equipment, Laboratory Use; Part 1, General Requirements for Safety conforms to UL STD 3101-1, conforms to EN 6010-1, EN 60601-1-1
Electronic Thumbwheel Display
Control Function Keys
98-131
0413
OVERVIEW This appendix provides methods of performing radioisotope decay calculations.
The first section provides two methods of performing Decay Calculations, the second section provides the Decay Factor Chart, and the third section provides an explanation of how the procedures used in the first section, and the Decay Factor Chart in the second section, are generated.
DECAY CALCULATION METHODS – CALCULATOR METHOD If you are using a calculator with the Y
x function, perform
the following:
1) Measure the current activity of the radioisotope (A0,) which can be compared to the calculated decayed activity.
2) Look up the half life T1/2 of the radioisotope in Appendix D. Note the time units.
3) T1/2 = Half life of the isotope t = Elapsed Time A = Current Activity A0 = Activity at the time of calibration
4) Calculate A = A0 x 2(-t/T1/2)
5) Calculate the elapsed time (t) in the same units as the (T1/2) that will elapse between when the calibrated activity measurement was made and when you wish to know what the decayed activity of your radioisotope will be.
The following is a calculation of the decayed activity of Tc- 99m, with an initial activity of 43 mCi, after 53 minutes:
1) A0 = 43 mCi.
ATOMLAB Dose Calibrator Operation Manual Appendix C
Biodex Medical Systems C-1 Release 2.0
Sample Calculation
3) Elapsed t = 53 min x 1 hr = 0.8833 hr 60 min
4) A = A0 x 2(-t/T1/2)
A = 43 mCi x 2(-0.8833/6.007)
A = 43 mCi x 2(-0.147045)
A = 43 mCi x 0.903 A = 38.83 mCi
DECAY FACTOR METHOD The following method is used to perform radioisotope decay calculations using a calculator without the ex function:
1) Measure the current activity Ai of the radioisotope.
2) Look up the half life T1/2 of the radioisotope in Appendix D. Note the time units.
3) Calculate the time t, in the same units as T1/2, that will elapse between when the activity measurement was made and when you wish to know what the decayed activity of your radioisotope will be.
4) Calculate t / T1/2 in terms of N + R, where N is an integer (0, 1, 2, etc.) and R is less than 1.
5) Look up Xn (N) in Table 1.
6) Look up Xr (R) in the Decay Factor Chart.
7) Calculate Af = Ai x Xn (N) x Xr (R).
The following is a calculation of the decayed activity of Tc- 99m, with an initial activity of 43 mCi, after 32.5 hours:
1) Ai = 43 mCi.
3) t = 32.5 h.
4) t / T1/2 = 32.5 h / 6.007 = 5.410. N = 5, R = 0.410.
ATOMLAB Dose Calibrator Operation Manual Appendix C
Sample Calculation
5) From Table 1, Xn (5) = 0.03125.
6) From the Decay Factor Chart, the .41 row and the .001 column, Xr (.410) = .75262.
7) Af = Ai x Xn (N) x Xr (R) = 43 mCi x (0.03125) x (.75262) = 1.01 mCi.
N Xn (N) = 2 -N
0 1 1 0.5 2 0.25 3 0.125 4 0.0625 5 0.03125 6 0.01563 7 0.007813 8 0.003906 9 0.001953 10 0.000977
Table 1
DECAY FACTOR CHART Xr (R), where R = t / T1/2 (0.000 to 0.499)
R .000 .001 .002 .003 .004 .005 .006 .007 .008 .009
.00 1.00000 .99931 .99861 .99792 .99723 .99654 .99585 .99516 .99447 .99378
.01 .99309 .99240 .99172 .99103 .99034 .98966 .98897 .98829 .98760 .98692
.02 .98623 .98555 .98487 .98418 .98350 .98282 .98214 .98146 .98078 .98010
.03 .97942 .97874 .97806 .97739 .97671 .97603 .97536 .97468 .97400 .97333
.04 .97265 .97198 .97131 .97063 .96996 .96929 .96862 .96795 .96728 .96661
.05 .96594 .96527 .96460 .96393 .96326 .96259 .96193 .96126 .96059 .95993
.06 .95926 .95860 .95794 .95727 .95661 .95595 .95528 .95462 .95396 .95330
.07 .95264 .95198 .95132 .95066 .95000 .94934 .94868 .94803 .94737 .94671
.08 .94606 .94540 .94475 .94409 .94344 .94278 .94213 .94148 .94083 .94017
.09 .93952 .93887 .93822 .93757 .93692 .93627 .93562 .93498 .93433 .93368
.10 .93303 .93239 .93174 .93109 .93045 .92980 .92916 .92852 .92787 .92723
.11 .92659 .92595 .92530 .92477 .92402 .92338 .92274 .92210 .92146 .92083
.12 .92019 .91955 .91891 .91828 .91764 .91700 .91637 .91573 .91510 .91447
.13 .91383 .91320 .91257 .91193 .91130 .91067 .91004 .90941 .90878 .90815
.14 .90752 .90689 .90626 .90563 .90501 .90438 .90375 .90313 .90250 .90188
.15 .90125 .90063 .90000 .89938 .89876 .89813 .89751 .89689 .89627 .89565
.16 .89503 .89440 .89379 .89317 .89255 .89193 .89131 .89069 .89008 .88946
.17 .88884 .88823 .88761 .88700 .88638 .88577 .88515 .88454 .88393 .88332
.18 .88270 .88209 .88148 .88087 .88026 .87965 .87904 .87843 .87782 .87721
.19 .87661 .87600 .87539 .87478 .87418 .87357 .87297 .87236 .87176 .87115
.20 .87055 .86995 .86934 .86874 .86814 .86754 .86694 .86634 .86574 .86514
.21 .86454 .86394 .86334 .86274 .86214 .86155 .86095 .86035 .85976 .85916
.22 .85857 .85797 .85738 .85678 .85619 .85559 .85500 .85441 .85382 .85323
.23 .85263 .85204 .85145 .85086 .85027 .84968 .84910 .84851 .84792 .84733
.24 .84675 .84616 .84557 .84499 .84440 .84382 .84323 .84265 .84206 .84148
.25 .84090 .84031 .83973 .83915 .83857 .83799 .83741 .83683 .83625 .83567
.26 .83509 .83451 .83393 .83335 .83278 .83220 .83162 .83105 .83047 .82989
.27 .82932 .82874 .82817 .82760 .82702 .82645 .82588 .82531 .82473 .82416
.28 .82359 .82302 .82245 .82188 .82131 .82074 .82017 .81960 .81904 .81847
.29 .81790 .81734 .81677 .81620 .81564 .81507 .81451 .81394 .81338 .81282
.30 .81225 .81169 .81113 .81057 .81000 .80944 .80888 .80832 .80776 .80720
.31 .80664 .80608 .80552 .80497 .80441 .80385 .80329 .80274 .80218 .80163
.32 .80107 .80051 .79996 .79941 .79885 .79830 .79775 .79719 .79664 .79609
.33 .79554 .79499 .79443 .79388 .79333 .79278 .79223 .79169 .79114 .79059
.34 .79004 .78949 .78895 .78840 .78785 .78731 .78676 .78622 .78567 .78513
.35 .78458 .78404 .78350 .78295 .78241 .78187 .78133 .78079 .78025 .77970
.36 .77916 .77862 .77809 .77755 .77701 .77647 .77593 .77539 .77486 .77432
.37 .77378 .77325 .77271 .77218 .77164 .77111 .77057 .77004 .76950 .76897
.38 .76844 .76791 .76737 .76684 .76631 .76578 .76525 .76472 .76419 .76366
.39 .76313 .76260 .76207 .76154 .76102 .76049 .75996 .75944 .75891 .75838
.40 .75786 .75733 .75681 .75628 .75576 .75524 .75471 .75419 .75367 .75315
.41 .75262 .75210 .75158 .75106 .75054 .75002 .74950 .74898 .74846 .74794
.42 .74742 .74691 .74639 .74587 .74536 .74484 .74432 .74381 .74329 .74278
.43 .74226 .74175 .74123 .74072 .74021 .73969 .73918 .73867 .73816 .73765

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ATOMLAB 100 DOSE CALIBRATOR - Biodex