Fluke 35040 5Automatic Leakage Compensation, The Test Function Screen Showing the Timer Settings

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Operation

Operation Instructions 3

ADC	Thres:	1.0	ALC
Start	Thres:	1.0	pA
Stop	Thres:	0.9	pA
Current:		0.0	pA

Figure 3-11. The Test Function Screen Showing the Automatic Leakage Compensation Settings

Figure 3-12 displays the settings for the timer interval, count mode, and decimal places. Refer to Section 3.9.6 for details.

ADCALC

Interval: 60 s

Count: UP

Decimal Places: 0

Figure 3-12. The Test Function Screen Showing the Timer Settings

Figure 3-13 shows the display format setting for the effective exposure time, which determines the presentation of the effective time on the Measurement screen.

ADC	ALC
Exp	Time: HR/MIN/SEC

Figure 3-13. The Test Function Screen Showing the Effective Exposure Time Display Setting

To change the effective time format setting, press the TEST FUNCTION button to show the "f" cursor and use the UP and DOWN arrow buttons to select either seconds (SECONDS) or hours/minutes/seconds (HR/MIN/SEC). Press the TEST FUNCTION button again to hide the cursor and save the selection.

3.9.5Automatic Leakage Compensation

Automatic compensation for leakage currents can be enabled and disabled from the front panel. Automatic leakage compensation allows the instrument to “detect” when an exposure is in progress and hold the final exposure measurement values between exposures.

The start threshold specifies the current necessary for the instrument to begin updating the exposure measurements. The stop threshold must be smaller than the start threshold, and it indicates the minimum current required for the exposure measurements to be updated once an exposure is detected. That is, the instrument will cease updating the exposure measurements when the current drops below the stop threshold and will return to measuring leakage.

NOTE

The instrument uses the start and stop threshold settings to sense when an exposure is in progress.

3-11

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Contents Therapy Dosimeter 35040Fluke Biomedical Table of Contents Sample Customization Reports Troubleshooting and ServiceAddendum Features of Firmware Version 27JAN00 or Later Iii Blank Introduction FeaturesIntroduction Operators Manual Before You Start Safety PrecautionsSafety Symbols And Terms Manual Addenda SpecificationsFactory Calibration Error Source ± %rdg Maximum ErrorCurrent Measurements Full Scale Range Display Resolution Noise ± countsFull Scale Range Display Resolution Timed Charge MeasurementsGeneral Measurements SpecificationsEffective Exposure Time Measurements High Performance Power Supply and Battery Charger Unpacking and Inspection 35040 Functional Description Hardware Block Diagram of the Model 35040 Therapy DosimeterSerial Communications Port Power SupplyFront Panel MicroControllerMultiplexer and A/D Converter Basic Operating EquationsElectrometer Bias SupplyQAccumprevious Quantity Description Units CommentsQExposure QAccum= time of electrometer conversion s Charge and Current MeasurementsLeakage Measurements Timed Charge and Dose Exposure Charge and DoseExposure Current and Rate Setting ThresholdsPredicted Timed Charge and Dose Accumulated Charge and DoseDoseRate = I a × Iccf Units/C × Adcf × RateMultiplier s Exposure TimeMm Hg = inch Hg x Air Density Correction Factor⎝ P Units Display Minimum Maximum Standard Resolution ErrorIntroduction SetupSetup Front Panel FamiliarizationRear Panel Familiarization Powering The SystemIon Chamber Connector Power-Up Self-Test and Display MessagesMaking Non-Timed Exposure Measurements Basic Measurement TechniquesGeneral Considerations 3Making Timed Exposure Measurements Timer SetupTimer Use Using Other Ion Chambers Battery CareFront Panel Controls PowerBattery Care Operation InstructionsPowering Up the Model 35040 Therapy Dosimeter Operation Instructions Powering Down the Model 35040 Therapy DosimeterUsing the Test Function Button QScaleFactor=1.0000 IScaleFactor=1.0000 5Automatic Leakage Compensation 12. The Test Function Screen Showing the Timer SettingsCalibrated by Keithley RMD Nov 15 17. The Test Function Screen Showing the Timer Settings 6Timer SetupUsing the AIR Density Button Using the Detector Select ButtonUsing the Bias Select Button Using the Units Select ButtonSet 300.0 V 100% Central Electrde Pos IC Bias 300.0 V CEP Overranging Conditions Using the RESET/MEASURE ButtonCondition Values Overranged Reset ErrorOverrange Conditions Annunciator Condition Reset Error With Automatic Leakage Compensation EnabledAnnunciators AnnunciatorsCondition Overranged Measurement Measurement Indicators and ConditionsIndicator Measurement Condition ? left of valueStarting the Customization Software Installing/Uninstalling Customization SoftwareCustomization Connection to the ComputerCOM Port Drop Down List DownloadingMenu Items and Controls File Save AS and File Print Ion ChambersClose or File Close Edit Special Items OK and Cancel36. The Special Items Menu Calibration Temperature has focus Download and CancelMeasurement Displays Display Line Operators Manual Available Display LinesChanging a Line on a Display Using the APPEND, DELETE, and Insert ButtonsDisplay Line Group Selection Selecting an Item and Placing It38. The Timer Intervals Form Timer Intervals39. The Bias Settings Form Bias SettingsExamples Deleting a Display Changing the Pressure UnitsCustomizing a Measurement Display Appending a DisplayErrors Troubleshooting Troubleshooting and ServiceSymptom LoBias annunciator displayed Symptom Display does not light up when Power is pressedSymptom ??Bias annunciator displayed Symptom HiBias annunciator displayedDo not make Symptom Internal Reset Error displayedSymptom Configuration Error displayed Bit Description ActionMeasurements. Return Symptom Current Overrange DisplayedSymptom Dashes displayed instead of digits Symptom Bias voltage measurement changes by one digitExample 299.9 to Display Will Not Light Hours? Is the battery voltage greater than 5.9 volts? Low BatteryLine Bias ErrorGo to Model 35040 Therapy Dosimeter Fuse Replacement Line Fuse ReplacementReplaceable Parts Information Interface Connector CleaningCleaning The Instrument Replaceable Parts Information Warranty InformationReplaceable Parts List Recalibration, Repair Information & Technical AssistanceBlank Sample Documents Sample Customization Reports35040 Appendix Sample Customization Reports 35040 Appendix Sample Customization Reports Blank Timed Measurements Introduction New FeaturesOverview Specifications Update New Features B SetupMaking Timed Exposure Measurements Timer Setup ProcedureTimer Use Procedure Setup B RESET/MEASUREAutomatic Leakage Compensation ADC ALCOperation Instructions B Start NA pA Stop Thres CurrentDecimal Places Timer SetupTable B-1. Annunciators Annunciators, Indicators, and Overrange ConditionsTable B-2. Measurement Indicators and Conditions Condition Overranged Measurement1 Table B-3. Overrange ConditionsTheory of Operation Theory Of OperationConfiguration Error Service Required Error Number Measurement Displays Main MenuMeasurement Menu 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