Fluke 90100 manual Setting the Electrometer Gains and Offsets, Charge Gain QG

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Model 90100

Operators Manual

The 35360A TRACKER Display supports four units of radiation. To convert between these units, use Table 5-1. This table was developed from accepted definitions of radiation units. While Table 5-1 shows sieverts and grays as equivalent, we acknowledge that other factors may contribute to this conversion. Additionally, the instrument allows you to display readings in monitor units. Because monitor units are not defined in terms of radiation units, and monitor units could vary from machine to machine, we suggest that you develop your own conversion factor from the Ion Chamber Calibration Units to monitor units.

Table 5-1. A Guideline to Converting Between Units

To Convert:	To:	Multiply By:

roentgen (R)	gray (Gy)	.00879

roentgen (R)	sievert (Sv)	.00879

roentgen (R)	rad	0.879

gray (Gy)	roentgen (R)	113.77

gray (Gy)	sievert (Sv)	1

gray (Gy)	rad	100

sievert (Sv)	roentgen (R)	113.77

sievert (Sv)	gray (Gy)	1

sievert (Sv)	rad	100

rad	roentgen (R)	1.1377

rad	gray (Gy)	.01

rad	sievert (Sv)	.01

DISPLAY CALIBRATION ITEMS

Charge Gain (QG)

The 35360A TRACKER Display uses the Charge Gain to convert the number from the analog-to-digital converter to charge. The Charge Gain must be in units of nanocoulombs per count.

Current Gain, Current Zero (IG and ADZ)

The 35360A TRACKER Display uses the Current Gain and Current Zero to convert the number from the analog-to-digital converter to current. The Current Gain must be in units of nanocoulombs per minute, and the Current Zero must be in units of counts.

Ion Chamber Calibration Factor (ICCF)

The 35360A TRACKER Display uses the Ion Chamber Calibration Factor to convert charge from the 35300A TRACKER Detector ion chambers to radiation units. The factory calibrates the 35300A TRACKER Detector in units of roentgens per nanocoulomb. The accuracy of the calibration factor is ± 2.5%.

5.7 Setting the Electrometer Gains and Offsets

To set the electrometer gains, you must have a Keithley Instruments, Inc. Model 263 Calibrator/Source or equivalent. The current required for calibration procedure below must be 15 nanoamperes ± 0.07%; the charge required for calibration procedure below must be 950 nanocoulombs ± 0.5%. The Electrometer Offsets must be specified before the Electrometer Gains.

5-6

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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 SelectPowering Down the Model 35360A Tracker Display Powering Up the Model 35360A Tracker DisplayUsing the TEST/DETECTOR Button 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 DisplayElectrometer Serial Communications PortMultiplexer and A/D Converter 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 Cleaning the Instrument Interface Connector CleaningReplaceable Parts Information 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