Fluke 90100 manual General Information, Introduction

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General Information

Introduction 1

Section 1

General Information

1.1 Introduction

The Model 90100 TRACKER is a radiation measurement system intended for use in quality assurance programs for high-energy accelerators and Co60 machines. While its ease of operation makes it ideal for daily checks of beam constancy, symmetry, and flatness, its portability makes it a good choice for field service engineers and consulting physicists. The two main components of the system are the Model 35360A TRACKER Display, and the Model 35300A Detector, see Figure 1-1.

Figure 1-1. Model 35360A TRACKER Display and Model 35300A Detector

The 35360A TRACKER Display contains a five-channel electrometer capable of producing measurements of both dose and dose rate. A microcontroller performs air density corrections and displays the measurement results on the 4 line by 20 character vacuum fluorescent display (VFD) directly in the user's choice of radiological units. An integrated rechargeable battery and a 300 V electronic bias supply greatly simplify maintenance of the system. Another important feature built into the 35360A TRACKER Display includes the capability for fully remote and automated operation via an RS-232 computer interface (software is not included).

The 35300A Detector contains an array of four orthogonally placed ion chambers on 10 cm radii from a fifth isocentrally located ion chamber. The five ion chambers are of a vented, circular, parallel-plate configuration and are fully guarded for low leakage. An overlay label on the outside of the 35300A Detector marks the ion chamber locations for alignment with a therapy source light field system. The 35300A Detector connects to the 35360A TRACKER Display through a lightweight interface cable. This

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Contents Tracker System Model Fluke Biomedical Table of Contents Appendix a Using Build-Up Maintenance and ServiceTheory of Operation CustomizationIntroduction General InformationModel FeaturesSafety Terms Before You Start Safety PrecautionsSpecifications Manual AddendaMechanical Specifications Nominal Ion Chamber CharacteristicsRecommended Operation Conditions Ion Chamber Factory CalibrationDisplay Mode Measurements ModeModel 35360A Tracker Display Electrometer / A-D ConverterUnpacking and Inspection High Performance Battery ChargerInterface Cable Detector to Display EnvironmentOptional Equipment Standard System ContentsBlank Rear Panel Familiarization OperationDetector Input Powering the SystemDisplay. Be sure to use the correct end of the cable 3 RS-232 Computer Interface RJ-45 Style Positioning the Model 35300A Detector in the BeamOperation Positioning the Model 353300A Detector in the Beam Front Panel Controls Operation InstructionsReset PowerTest/Detector Units SelectUsing the TEST/DETECTOR Button Powering Up the Model 35360A Tracker DisplayPowering Down the Model 35360A Tracker Display Test/Detector Screen 2 Ion Chamber Calibration Factors Using the Units Select ButtonUsing the Gain Select Button Normal Mode Using the AIR Density ButtonAbsolute Measurements Using the Measure Select Button Normal ModePercent-of-Center Measurements Underranging and Overranging Conditions Battery and Bias Annunciators24. Positions of the Battery and Bias Annunciators Gain Setting ModeAborting the Fpgf Changes Saving the Fpgf ChangesBlank Theory of Operation Hardware Block Diagram of the Model 35360A Tracker Display Power Supply2 300-VOLT Electronic Bias Supply Front Panel SwitchesProcessor VFD DisplayMultiplexer and A/D Converter Serial Communications PortElectrometer Air Density Corrections Model 35300A Ion Chamber DetectorsBasic Operating Equations Basic Operating Quantities Blank Maintenance & Service Problem TroubleshootingNo Display Flowchart Low battery Yes Annuciator displayed? Low Battery Indication at the Display35360A Tracker Bias Error LoBias or HiBias Indication at the DisplayLeakage Flowchart Dose Rate Measurement Zero Problem Flowchart Line Fuse ReplacementIf fuses continue to blow return instrument for repair Replaceable Parts Information Interface Connector CleaningCleaning the Instrument Recalibration & Repair Information / Technical Assistance Replaceable Parts ListCustomization Connection to the Computer Make a Working DiskStarting the Customization Software Screen FormatsDisplay Customization Items Screen Appearance F2 Edit Item Editing F1 Help On-Line Help for using the Customization softwareF6 Print Report Printing F10 ExitDefinitions Charge Gain QG Setting the Electrometer Gains and OffsetsCurrent Gain, Current Zero IG and ADZ Ion Chamber Calibration Factor IccfElectrometer Charge Gains QG Electrometer Current Gain IGUsage Examples Changing the Power Down IntervalChanging the ION Chamber Calibration Factor Units Input Errors ErrorsBuild-Up, Peg, and Retainer Kit Options Using Build-UpNominal Number of build-up Solid Water Appendix Fluke Biomedical