Start NA pA Stop Thres Current | Fluke 35040 specs

Appendix

Operation Instructions B

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.

With the automatic leakage compensation settings displayed (Figure B-4), press the TEST FUNCTION

button. The "" cursor will appear to the left of the ALC annunciator. Use the UP and DOWN arrow buttons to toggle the setting between on (ALC) and off (OFF).

With automatic leakage compensation enabled, press the TEST FUNCTION button to advance the "" cursor to the next field or exit Edit mode. When the cursor points to a threshold setting, use the UP and DOWN arrow buttons to increment and decrement the value, respectively. Nominal values for the start and stop thresholds are 1.3 and 1.2 pA, respectively. However, depending on the system leakage, other values may be necessary.

When automatic leakage compensation is disabled, the annunciator displays off (OFF) (Figure B-5), the start and stop threshold settings cannot be changed and display Not Available (NA), as do the leakage

ADC		1.0	ALC
Start Thres:			pA
Stop	Thres:	0.9	pA
Current:		0.0	pA
measurements.
Figure B-4.	Automatic Leakage Compensation Enabled
Figure B-5.	Automatic Leakage Compensation Disabled

NOTE

The instrument may reset all measurements when

ADC	Thres:		OFF
Start	Thres:	NA pA
Stop	Thres:	NA	pA
Current:		0.0	pA

the automatic leakage compensation parameters are changed.

NOTE

Disabling automatic leakage compensation prevents automatic exposure detection and the measurement of leakage current, and leakage measurements will display Not Available (NA).

B-7

Image 83

Fluke 35040 manual Start NA pA Stop Thres Current, Operation Instructions B

Contents

Therapy Dosimeter 35040 Fluke 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 Error Current Measurements Full Scale Range Display Resolution Noise ± countsFull Scale Range Display Resolution Timed Charge Measurements General 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 Dosimeter Serial Communications Port Power SupplyFront Panel MicroController Multiplexer and A/D Converter Basic Operating EquationsElectrometer Bias Supply QAccumprevious Quantity Description Units CommentsQExposure QAccum = time of electrometer conversion s Charge and Current MeasurementsLeakage Measurements Timed Charge and Dose Exposure Charge and Dose Exposure Current and Rate Setting ThresholdsPredicted Timed Charge and Dose Accumulated Charge and Dose DoseRate = I a × Iccf Units/C × Adcf × RateMultiplier s Exposure Time Mm Hg = inch Hg x Air Density Correction Factor⎝ P Units Display Minimum Maximum Standard Resolution Error Introduction SetupSetup Front Panel Familiarization Rear Panel Familiarization Powering The System Ion Chamber Connector Power-Up Self-Test and Display Messages Making Non-Timed Exposure Measurements Basic Measurement TechniquesGeneral Considerations 3Making Timed Exposure Measurements Timer SetupTimer Use Using Other Ion Chambers Battery Care Front Panel Controls PowerBattery Care Operation Instructions Powering 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 Settings Calibrated by Keithley RMD Nov 15 17. The Test Function Screen Showing the Timer Settings 6Timer Setup Using the AIR Density Button Using the Detector Select Button Using the Bias Select Button Using the Units Select Button Set 300.0 V 100% Central Electrde Pos IC Bias 300.0 V CEP Overranging Conditions Using the RESET/MEASURE Button Condition Values Overranged Reset ErrorOverrange Conditions Annunciator Condition Reset Error With Automatic Leakage Compensation EnabledAnnunciators Annunciators Condition Overranged Measurement Measurement Indicators and ConditionsIndicator Measurement Condition ? left of value Starting the Customization Software Installing/Uninstalling Customization SoftwareCustomization Connection to the Computer COM Port Drop Down List DownloadingMenu Items and Controls File Save AS and File Print Ion ChambersClose or File Close Edit Special Items OK and Cancel 36. The Special Items Menu Calibration Temperature has focus Download and Cancel Measurement Displays Display Line Operators Manual Available Display Lines Changing a Line on a Display Using the APPEND, DELETE, and Insert ButtonsDisplay Line Group Selection Selecting an Item and Placing It 38. The Timer Intervals Form Timer Intervals 39. The Bias Settings Form Bias Settings Examples Deleting a Display Changing the Pressure UnitsCustomizing a Measurement Display Appending a Display Errors Troubleshooting Troubleshooting and Service Symptom LoBias annunciator displayed Symptom Display does not light up when Power is pressedSymptom ??Bias annunciator displayed Symptom HiBias annunciator displayed Do not make Symptom Internal Reset Error displayedSymptom Configuration Error displayed Bit Description Action Measurements. Return Symptom Current Overrange DisplayedSymptom Dashes displayed instead of digits Symptom Bias voltage measurement changes by one digit Example 299.9 to Display Will Not Light Hours? Is the battery voltage greater than 5.9 volts? Low Battery Line Bias ErrorGo to Model 35040 Therapy Dosimeter Fuse Replacement Line Fuse Replacement Replaceable Parts Information Interface Connector CleaningCleaning The Instrument Replaceable Parts Information Warranty InformationReplaceable Parts List Recalibration, Repair Information & Technical Assistance Blank Sample Documents Sample Customization Reports 35040 Appendix Sample Customization Reports 35040 Appendix Sample Customization Reports Blank Timed Measurements Introduction New FeaturesOverview Specifications Update New Features B Setup Making Timed Exposure Measurements Timer Setup ProcedureTimer Use Procedure Setup B RESET/MEASURE Automatic Leakage Compensation ADC ALC Operation Instructions B Start NA pA Stop Thres Current Decimal Places Timer Setup Table B-1. Annunciators Annunciators, Indicators, and Overrange ConditionsTable B-2. Measurement Indicators and Conditions Condition Overranged Measurement1 Table B-3. Overrange Conditions Theory of Operation Theory Of Operation Configuration 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