Fluke 90100 manual Recommended Operation Conditions, Nominal Ion Chamber Characteristics

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Model 90100

Operators Manual

Recommended Operation Conditions

Source Distance: 100 cm

Collimated Field Size: 25 ⋅ 25 cm

Source Dose Rate Range: 50 to 500 rads/min

Nominal Ion Chamber Characteristics

Wall and Window Material: Continental Polymers ACRYCAL-CP or equivalent

Window Area Density: 600 mg/sq cm (0.51 cm acrylic plastic)

Window Transmission: 95% for 662 keV photons; for electrons, transmission through window occurs above 1.5 MeV.

Sensitivity: 3.52 R/nC at 22°C and 760 mm Hg

Active Volume: 0.93 cc ±5%

Active Diameter: 1.162 cm

Active Cross-Sectional Area: 1.06 sq cm

Collector-to-Bias Separation: 0.44 cm

Ion Transit Time: 0.418 ms @ bias voltage of 300V

Collection Efficiency: >99% at 500 rads/min pulsed; >99.9% at 500 rads/min continuous

Leakage: Less than 0.5 pA over the full operating temperature range

Ion Chamber Factory Calibration

Method: Each of the 5 ion chambers within the detector array is calibrated by comparison with a reference standard ion chamber in a Co60 beam. The comparison is performed in free air and results

in an R/nC Calibration Factor for each of the five ion chambers.

Comparison Standard: 0.6 cc NE Farmer Probe with 3 MeV buildup cap.

Uncertainty: 2.5% using IEC/NIST guidelines.

Mechanical Specifications

Detector Configuration: The detector array consists of four orthogonally placed ion chambers on 10 cm radii from a fifth centrally located ion chamber.

Dimensions: 33.7 cm wide x 43.8 cm deep x 2.2 cm high (13.25 in. x 17.25 in. x 0.875 in.). Depth dimension assumes handle is fully extended; height dimension assumes no accessory pegs or build-up added.

Weight: 4 kg (8.8 lbs)

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Contents Model Tracker SystemFluke Biomedical Table of Contents Maintenance and Service Appendix a Using Build-UpTheory of Operation CustomizationGeneral Information IntroductionFeatures ModelBefore You Start Safety Precautions Safety TermsSpecifications Manual AddendaNominal Ion Chamber Characteristics Mechanical SpecificationsRecommended Operation Conditions Ion Chamber Factory CalibrationMeasurements Mode Display ModeModel 35360A Tracker Display Electrometer / A-D ConverterHigh Performance Battery Charger Unpacking and InspectionInterface Cable Detector to Display EnvironmentStandard System Contents Optional EquipmentBlank Operation Rear Panel FamiliarizationPowering the System Detector InputDisplay. Be sure to use the correct end of the cable Positioning the Model 35300A Detector in the Beam 3 RS-232 Computer Interface RJ-45 StyleOperation Positioning the Model 353300A Detector in the Beam Operation Instructions Front Panel ControlsPower ResetTest/Detector Units SelectUsing the TEST/DETECTOR Button Powering Up the Model 35360A Tracker DisplayPowering Down the Model 35360A Tracker Display Using the Units Select Button Test/Detector Screen 2 Ion Chamber Calibration FactorsUsing the AIR Density Button Using the Gain Select Button Normal ModeUsing the Measure Select Button Normal Mode Absolute MeasurementsPercent-of-Center Measurements Battery and Bias Annunciators Underranging and Overranging ConditionsGain Setting Mode 24. Positions of the Battery and Bias AnnunciatorsSaving the Fpgf Changes Aborting the Fpgf ChangesBlank Theory of Operation Power Supply Hardware Block Diagram of the Model 35360A Tracker DisplayFront Panel Switches 2 300-VOLT Electronic Bias SupplyProcessor VFD DisplayMultiplexer and A/D Converter Serial Communications PortElectrometer Model 35300A Ion Chamber Detectors Air Density CorrectionsBasic Operating Equations Basic Operating Quantities Blank Maintenance & Service Troubleshooting ProblemNo Display Flowchart Low Battery Indication at the Display Low battery Yes Annuciator displayed?Bias Error LoBias or HiBias Indication at the Display 35360A TrackerLeakage Flowchart Line Fuse Replacement Dose Rate Measurement Zero Problem FlowchartIf fuses continue to blow return instrument for repair Replaceable Parts Information Interface Connector CleaningCleaning the Instrument Replaceable Parts List Recalibration & Repair Information / Technical AssistanceCustomization Make a Working Disk Connection to the ComputerStarting the Customization Software Screen FormatsDisplay Customization Items Screen Appearance F1 Help On-Line Help for using the Customization software F2 Edit Item EditingF6 Print Report Printing F10 ExitDefinitions Setting the Electrometer Gains and Offsets Charge Gain QGCurrent Gain, Current Zero IG and ADZ Ion Chamber Calibration Factor IccfElectrometer Current Gain IG Electrometer Charge Gains QGChanging the Power Down Interval Usage ExamplesChanging the ION Chamber Calibration Factor Units Errors Input ErrorsUsing Build-Up Build-Up, Peg, and Retainer Kit OptionsNominal Number of build-up Solid Water Appendix Fluke Biomedical