Fluke 35040 manual QScaleFactor=1.0000 IScaleFactor=1.0000

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35040

Operators Manual

Figure 3-8 shows the ion chamber bias voltage (IC Bias), the system leakage current (Leakage), and the battery voltage and current. The bias voltage shown is 300.0 volts. The central electrode is positive (CEP). The leakage current is 0.001 picoamps. The battery current is a small positive number, thus the battery is charging and is almost fully charged.

ADC

Batt: 6.8 V +0.10 A

Leakage: 0.001 pA

IC Bias: 300.0 V CEP

Figure 3-8. The Test Function Screen 2 - Bias, Leakage, and Battery Voltage and Current

The battery current (shown in Figure 3-8), “+0.1 A”, is displayed to the right of the battery voltage, “6.8 V”. A positive current value of up to 2.5 amperes indicates that the battery is being charged from the AC line. As the battery approaches full charge, the current will decrease to near zero. A negative current value will be shown when the instrument is operated from battery power. A negative current indicates the actual current consumption of the instrument.

During a charging cycle, the battery voltage can range from 5.5 volts to 8.5 volts. After the battery reaches its full charge, the charging circuit switches to float charge stage with a corresponding voltage of approximately 7 volts. The unit will remain in the float charge stage as long as the instrument is attached to an AC line. When the instrument is operated from battery power, the voltage will read between 6.5 volts (battery fully charged) and 5.4 volts (low battery shutdown voltage).

The two scale factors that appear in Figure 3-9 are those determined by a calibration agency. QScaleFactor adjusts the charge. IScaleFactor adjusts the current. See Section 2.3 for details.

ADC

QScaleFactor=1.0000

IScaleFactor=1.0000

Figure 3-9. The Test Function Screen 3 - Calibration Scale Factors

Figure 3-10 shows the present settings for the start and stop threshold currents and the instantaneous current measurement. See Section 3.9.5 for details.

ADC

Start Thres: 1.0pA

Stop Thres: 0.9pA

Current: 0.0pA

Figure 3-10. The Test Function Screen 4 - Leakage Threshold Screen

Figure 3-11 shows the automatic leakage compensation settings, which consist of the ALC status, start and stop threshold currents, and the instantaneous current measurement. Refer to Section 3.9.5 for details.

3-10

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Contents 35040 Therapy DosimeterFluke Biomedical Table of Contents Addendum Features of Firmware Version 27JAN00 or Later Troubleshooting and ServiceSample Customization Reports Iii Blank Introduction FeaturesIntroduction Safety Symbols And Terms Before You Start Safety PrecautionsOperators Manual Maximum Error SpecificationsFactory Calibration Error Source ± %rdg Manual AddendaTimed Charge Measurements Full Scale Range Display Resolution Noise ± countsFull Scale Range Display Resolution Current MeasurementsEffective Exposure Time Measurements SpecificationsGeneral Measurements High Performance Power Supply and Battery Charger Unpacking and Inspection 35040 Hardware Block Diagram of the Model 35040 Therapy Dosimeter Functional DescriptionMicroController Power SupplyFront Panel Serial Communications PortBias Supply Basic Operating EquationsElectrometer Multiplexer and A/D ConverterQAccum Quantity Description Units CommentsQExposure QAccumpreviousLeakage Measurements Charge and Current Measurements= time of electrometer conversion s Exposure Charge and Dose Timed Charge and DoseAccumulated Charge and Dose Setting ThresholdsPredicted Timed Charge and Dose Exposure Current and RateExposure Time DoseRate = I a × Iccf Units/C × Adcf × RateMultiplier s⎝ P Air Density Correction FactorMm Hg = inch Hg x Standard Resolution Error Units Display Minimum MaximumFront Panel Familiarization SetupSetup IntroductionPowering The System Rear Panel FamiliarizationPower-Up Self-Test and Display Messages Ion Chamber ConnectorGeneral Considerations Basic Measurement TechniquesMaking Non-Timed Exposure Measurements Timer Use Timer Setup3Making Timed Exposure Measurements Battery Care Using Other Ion ChambersOperation Instructions PowerBattery Care Front Panel ControlsPowering Up the Model 35040 Therapy Dosimeter Using the Test Function Button Powering Down the Model 35040 Therapy DosimeterOperation Instructions QScaleFactor=1.0000 IScaleFactor=1.0000 12. The Test Function Screen Showing the Timer Settings 5Automatic Leakage CompensationCalibrated by Keithley RMD Nov 15 6Timer Setup 17. The Test Function Screen Showing the Timer SettingsUsing the Detector Select Button Using the AIR Density ButtonUsing the Units Select Button Using the Bias Select ButtonSet 300.0 V 100% Central Electrde Pos IC Bias 300.0 V CEP Using the RESET/MEASURE Button Overranging ConditionsOverrange Conditions Reset ErrorCondition Values Overranged Annunciators Reset Error With Automatic Leakage Compensation EnabledAnnunciators Annunciator Condition? left of value Measurement Indicators and ConditionsIndicator Measurement Condition Condition Overranged MeasurementConnection to the Computer Installing/Uninstalling Customization SoftwareCustomization Starting the Customization SoftwareMenu Items and Controls DownloadingCOM Port Drop Down List Close or File Close Ion ChambersFile Save AS and File Print Edit OK and Cancel Special ItemsDownload and Cancel 36. The Special Items Menu Calibration Temperature has focusMeasurement Displays Operators Manual Available Display Lines Display LineSelecting an Item and Placing It Using the APPEND, DELETE, and Insert ButtonsDisplay Line Group Selection Changing a Line on a DisplayTimer Intervals 38. The Timer Intervals FormBias Settings 39. The Bias Settings FormExamples Appending a Display Changing the Pressure UnitsCustomizing a Measurement Display Deleting a DisplayErrors Troubleshooting and Service TroubleshootingSymptom HiBias annunciator displayed Symptom Display does not light up when Power is pressedSymptom ??Bias annunciator displayed Symptom LoBias annunciator displayedBit Description Action Symptom Internal Reset Error displayedSymptom Configuration Error displayed Do not makeSymptom Bias voltage measurement changes by one digit Symptom Current Overrange DisplayedSymptom Dashes displayed instead of digits Measurements. ReturnExample 299.9 to Display Will Not Light Low Battery Hours? Is the battery voltage greater than 5.9 volts?Go to Bias ErrorLine Line Fuse Replacement Model 35040 Therapy Dosimeter Fuse ReplacementCleaning The Instrument Interface Connector CleaningReplaceable Parts Information Recalibration, Repair Information & Technical Assistance Warranty InformationReplaceable Parts List Replaceable Parts InformationBlank Sample Customization Reports Sample Documents35040 Appendix Sample Customization Reports 35040 Appendix Sample Customization Reports Blank Overview Introduction New FeaturesTimed Measurements Specifications Update Setup New Features BTimer Use Procedure Timer Setup ProcedureMaking Timed Exposure Measurements RESET/MEASURE Setup BADC ALC Automatic Leakage CompensationStart NA pA Stop Thres Current Operation Instructions BTimer Setup Decimal PlacesTable B-2. Measurement Indicators and Conditions Annunciators, Indicators, and Overrange ConditionsTable B-1. Annunciators Table B-3. Overrange Conditions Condition Overranged Measurement1Theory Of Operation Theory of OperationConfiguration Error Service Required Error Number Measurement Menu Main MenuMeasurement Displays Figure B-9 shows the Measurement Displays dialog box Table B-4. Available Display Lines Figure B-10. The Timer Intervals dialog box Page Fluke Biomedical