Fluke 90100 manual Electrometer Current Gain IG, Electrometer Charge Gains QG

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Customization

5

Setting the Electrometer Gains and Offsets

ELECTROMETER OFFSET (ADZ)

The procedure for setting the electrometer offsets for current and charge is the same. For every electrometer channel, repeat this procedure once. Turn the instrument off and disconnect the interface cable if it is connected.

WARNING

Always turn the Model 35360A TRACKER Display's power off prior to connecting or disconnecting the interface cable. Failure to do so may result in an electrical shock.

Turn on the instrument. Place the 35360A TRACKER Display in rate mode. Turn off the Front Panel Gain Factor (FPGF) and the Air Density Correction Factor (ADCF).

1.Reset the instrument. Note the dose rate offset value for the channel under adjustment displayed on the VFD. Also note the old ADZ value for the channel under adjustment on the Display Calibration Items screen. Calculate a new ADZ value using the following equation:

ADZNew = ADZOld + (Dose Rate Offset) / (Current Gain × ICCF × DUCF)

2.Add the value calculated in Step 1 to the original ADZ. Enter this value into the Display Calibration Items screen of the Customization software. Be sure to enter it in the correct column and row. For example, if you are setting the charge offset for the Top chamber, enter the calculated value in the first column and second row.

3.Repeat Steps 1 and 2 if the value displayed on the 35360A TRACKER Display is not zero.

ELECTROMETER GAINS

The procedure for setting the electrometer gains differs for current and charge. For every electrometer channel, repeat the gain setting procedure for current and charge. Turn off the Front Panel Gain Factors and the Air Density Correction Factor. This procedure requires a special cable. Consult the factory for details.

Electrometer Current Gain (IG)

1.Apply 15 nanoamperes (900 nC/min) to the input of an electrometer channel.

2.Check the measurement on the 35360A TRACKER Display's Front Panel. Calculate the new Current Gain factor using the equation below.

New Current Gain = Old Current Gain 900 x ICCF x DUCF

Measurement

where Measurement is the value on the 35360A TRACKER Display, and ICCF and DUCF are defined on page 60 and page 59 respectively.

3.Enter the value calculated in Step 2 into the Display Calibration Items screen of the Customization software. Be sure to enter it in the correct column and row. For example, if you are setting the current gain for the Right chamber, enter the value calculated in Step 1 in the fourth column and third row.

Electrometer Charge Gains (QG)

1.Reset the instrument and apply 950 nanocoulombs to the input of an electrometer channel.

2.Check the measurement on the 35360A TRACKER Display's Front Panel. Calculate the new Charge Gain factor using the equation below.

New Charge Gain = Old Charge Gain 950 x ICCF x DUCF

Measurement

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Contents Tracker System ModelFluke Biomedical Table of Contents Appendix a Using Build-Up Maintenance and ServiceTheory of Operation CustomizationIntroduction General InformationModel FeaturesSafety Terms Before You Start Safety PrecautionsSpecifications Manual AddendaMechanical Specifications Nominal Ion Chamber CharacteristicsRecommended Operation Conditions Ion Chamber Factory CalibrationDisplay Mode Measurements ModeModel 35360A Tracker Display Electrometer / A-D ConverterUnpacking and Inspection High Performance Battery ChargerInterface Cable Detector to Display EnvironmentOptional Equipment Standard System ContentsBlank Rear Panel Familiarization OperationDetector Input Powering the SystemDisplay. Be sure to use the correct end of the cable 3 RS-232 Computer Interface RJ-45 Style Positioning the Model 35300A Detector in the BeamOperation Positioning the Model 353300A Detector in the Beam Front Panel Controls Operation InstructionsReset PowerTest/Detector Units SelectUsing the TEST/DETECTOR Button Powering Up the Model 35360A Tracker DisplayPowering Down the Model 35360A Tracker Display Test/Detector Screen 2 Ion Chamber Calibration Factors Using the Units Select ButtonUsing the Gain Select Button Normal Mode Using the AIR Density ButtonAbsolute Measurements Using the Measure Select Button Normal ModePercent-of-Center Measurements Underranging and Overranging Conditions Battery and Bias Annunciators24. Positions of the Battery and Bias Annunciators Gain Setting ModeAborting the Fpgf Changes Saving the Fpgf ChangesBlank Theory of Operation Hardware Block Diagram of the Model 35360A Tracker Display Power Supply2 300-VOLT Electronic Bias Supply Front Panel SwitchesProcessor VFD DisplayMultiplexer and A/D Converter Serial Communications PortElectrometer Air Density Corrections Model 35300A Ion Chamber DetectorsBasic Operating Equations Basic Operating Quantities Blank Maintenance & Service Problem TroubleshootingNo Display Flowchart Low battery Yes Annuciator displayed? Low Battery Indication at the Display35360A Tracker Bias Error LoBias or HiBias Indication at the DisplayLeakage Flowchart Dose Rate Measurement Zero Problem Flowchart Line Fuse ReplacementIf fuses continue to blow return instrument for repair Replaceable Parts Information Interface Connector CleaningCleaning the Instrument Recalibration & Repair Information / Technical Assistance Replaceable Parts ListCustomization Connection to the Computer Make a Working DiskStarting the Customization Software Screen FormatsDisplay Customization Items Screen Appearance F2 Edit Item Editing F1 Help On-Line Help for using the Customization softwareF6 Print Report Printing F10 ExitDefinitions Charge Gain QG Setting the Electrometer Gains and OffsetsCurrent Gain, Current Zero IG and ADZ Ion Chamber Calibration Factor IccfElectrometer Charge Gains QG Electrometer Current Gain IGUsage Examples Changing the Power Down IntervalChanging the ION Chamber Calibration Factor Units Input Errors ErrorsBuild-Up, Peg, and Retainer Kit Options Using Build-UpNominal Number of build-up Solid Water Appendix Fluke Biomedical
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