Fluke 90100 manual Model 35360A Tracker Display, Measurements Mode, Display Mode

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General Information

Specifications 1

1.6.2 Model 35360A TRACKER Display

Measurements Mode

The measurement mode is user-selected from the front panel prior to the start of the exposure.

Dose (rad): Electrometer is operated in integrating mode with capacitive feedback.

Dose Rate (rad/min): Electrometer is operated in non-integrating mode with resistive feedback.

Display Mode

The display mode is user-selected from the front panel and may be selected before, during, or following the exposure.

Absolute: All five ion chamber measurement values are displayed in absolute dose measurement units (typically rads or rad/min) as defined by the dose measurement unit's description.

Percent-of-Center: Only the center ion chamber measurement value is displayed in absolute dose measurement units (typically rad or rad/min) as defined by the dose measurement unit's description.

Four peripheral ion chamber measurement values (top, bottom, left, and right) are displayed as a percentage of the center ion chamber measurement value.

Electrometer / A-D Converter

Nominal Full Scale Output: 3 volts.

A/D Converter Resolution: 16 bits unipolar.

Nominal Full Scale and Sensitivity in Electrical Units:

A-D Dose

A-D Dose

A-D Rate

A-D Rate

Full Scale

Sensitivity

Full Scale

Sensitivity

1000.0 nC ± 2%

0.015 nC/count

1000.0 nC/min ± 2%

0.015 (nC/min)/count

 

 

 

 

An overrange indication will be displayed when the input current or charge have exceeded the full-scale values. The full-scale value of any unit is guaranteed not to differ from nominal values by more than ± 2%.

Long Term Stability: Expected to be less than 0.25% of reading per year.

Non-linearity: Less than ± 0.4% of range.

Display Resolution: 0.003% of range (4-3/4 digits) for both dose and dose rate. Display resolution is limited by the following relationship for all display units;

1 A-D Count 1 Display Count < 10 A-D Counts.

This relationship insures that the resolution of the measurement display values is as high as possible without exceeding the inherent resolving capability of the

A-D converter.

Gain Temperature Stability: Less than ± 0.4% of reading over operating range of 10°C to 35°C.

Measurement Noise: Charge and Current measurement noise are less than ± 1 count at the display exclusive of source noise effects. Typical effects from a Co60 source are on the order of ± 0.2 rad/min

at 100 rad/min. Source noise effects during dose rate measurements on a linear accelerator may be excessive.

Measurement Accuracy: Fluke Biomedical factory calibration will provide a basic Charge (Current) measurement accuracy of ±1% of reading ± 0.3 nC (± 0.3 nC /min) exclusive of long-term drift and temperature effects. Similar results may be obtained in the field using a suitable calibration source such as the Keithley Instruments, Inc. Model 263 Calibrator/Source and the included Customization software.

Current Leakage: Less than 1 pA (typically 1 rad in 5 minutes)

Zero Offset Voltage: Factory trimmed to 0 counts at the display.

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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 SelectPowering Up the Model 35360A Tracker Display Powering Down the Model 35360A Tracker DisplayUsing the TEST/DETECTOR Button 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 DisplaySerial Communications Port ElectrometerMultiplexer and A/D Converter 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 Interface Connector Cleaning Cleaning the InstrumentReplaceable Parts Information 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