Fluke 35040 manual Power Supply, Front Panel, MicroController, Serial Communications Port

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35040

Operators Manual

2.2.1 Power Supply

During operation, the instrument may be powered by line voltage in the range of 100 to 240 VAC or from the internal 6 volt sealed lead acid battery for up to 8 hours. The power supply consists of a high performance charger that continuously charges the battery whenever the instrument is plugged in. The charger has three charging stages.

First stage: if the battery is fully discharged, the charger slowly recharges the battery until all cells in the battery have a minimum charge level on them. The instrument will not operate until the battery has more than the minimum charge on each cell. The first stage may be more than 18 hours depending on how severely discharged the battery is.

Second stage: the charger enters a high charge rate that can restore more than 80% of the charge in 2 to 3 hours - even during normal operation. The battery voltage will range from 5.5 to 8.5 volts. The battery current may be as high as 2.5 amps. After 3 hours of charging, the battery has enough charge for 8 hours of continuous operation.

Third stage: the charger enters a float charge stage that can be used indefinitely to maintain a full charge on the battery without harm. The battery voltage is approximately 7 volts. The current will range from 0.5 to 0.01 amps. The lower the current, the closer the battery is to full capacity. For additional information on care of the battery, see Section 3.8.

When operating from batteries, the battery current will be negative. The battery voltage will range from

6.5volts to 5.4 volts. There are two automatic mechanisms to prevent excessive discharge of the battery. If the voltage drops below 5.9 volts, a low battery annunciator (LoBat) is displayed on the front panel. Less than 30 minutes of operating time are left. When the voltage drops to 5.4 volts, the firmware automatically turns off the instrument. The hardware will turn off the power if the voltage drops below 5.4 volts.

The AC Power Line is fused as it enters the instrument with two fuses. These external fuses may be replaced by the user (see Section 4.6 for details).

2.2.2 Front Panel

Pressing the power switch, an isolated, momentary-contact switch, once turns the power on. Pressing it again turns the power off. At least 5 seconds should elapse after turning the power off to let the internal parts reset before trying to turn power back on. The other keys, a matrix of 8 open contact membrane switches, are scanned when any key closure is detected. The key code is stored until it is used. The four line by twenty-character vacuum fluorescent display is easy to read over a wide range of lighting conditions.

2.2.3 MicroController

A Motorola processor controls the instrument. The operating program is stored in EPROM. RAM is used for volatile storage. Calibration parameters (gains and offsets) and customization parameters (ion chamber calibration factors, pressure, and temperature units, bias settings) are stored in EEPROM. Each time the instrument is turned off, all front panel settings are stored in a small portion of the EEPROM. The settings are restored when the instrument is turned on.

2.2.4 Serial Communications Port

The serial port is configured as an RS-232C data communications device (DCE) running at 9600 baud, 8 bits, no parity, and 1 stop bit. The protocol uses XON/XOFF handshaking. This port is used for factory calibration and testing, for calibration, for customization, and for remote control/data acquisition. Inadvertent changes of the calibration or customization parameters are prevented by use of a three-step sequence.

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Contents 35040 Therapy DosimeterFluke Biomedical Table of Contents Addendum Features of Firmware Version 27JAN00 or Later Troubleshooting and ServiceSample Customization Reports Iii Blank Introduction FeaturesIntroduction Safety Symbols And Terms Before You Start Safety PrecautionsOperators Manual Specifications Factory Calibration Error Source ± %rdgMaximum Error Manual AddendaFull Scale Range Display Resolution Noise ± counts Full Scale Range Display ResolutionTimed Charge Measurements Current MeasurementsEffective Exposure Time Measurements SpecificationsGeneral Measurements High Performance Power Supply and Battery Charger Unpacking and Inspection 35040 Hardware Block Diagram of the Model 35040 Therapy Dosimeter Functional DescriptionPower Supply Front PanelMicroController Serial Communications PortBasic Operating Equations ElectrometerBias Supply Multiplexer and A/D ConverterQuantity Description Units Comments QExposureQAccum QAccumpreviousLeakage Measurements Charge and Current Measurements= time of electrometer conversion s Exposure Charge and Dose Timed Charge and DoseSetting Thresholds Predicted Timed Charge and DoseAccumulated Charge and Dose Exposure Current and RateExposure Time DoseRate = I a × Iccf Units/C × Adcf × RateMultiplier s⎝ P Air Density Correction FactorMm Hg = inch Hg x Standard Resolution Error Units Display Minimum MaximumSetup SetupFront Panel Familiarization IntroductionPowering The System Rear Panel FamiliarizationPower-Up Self-Test and Display Messages Ion Chamber ConnectorGeneral Considerations Basic Measurement TechniquesMaking Non-Timed Exposure Measurements Timer Use Timer Setup3Making Timed Exposure Measurements Battery Care Using Other Ion ChambersPower Battery CareOperation Instructions Front Panel ControlsPowering Up the Model 35040 Therapy Dosimeter Using the Test Function Button Powering Down the Model 35040 Therapy DosimeterOperation Instructions QScaleFactor=1.0000 IScaleFactor=1.0000 12. The Test Function Screen Showing the Timer Settings 5Automatic Leakage CompensationCalibrated by Keithley RMD Nov 15 6Timer Setup 17. The Test Function Screen Showing the Timer SettingsUsing the Detector Select Button Using the AIR Density ButtonUsing the Units Select Button Using the Bias Select ButtonSet 300.0 V 100% Central Electrde Pos IC Bias 300.0 V CEP Using the RESET/MEASURE Button Overranging ConditionsOverrange Conditions Reset ErrorCondition Values Overranged Reset Error With Automatic Leakage Compensation Enabled AnnunciatorsAnnunciators Annunciator ConditionMeasurement Indicators and Conditions Indicator Measurement Condition? left of value Condition Overranged MeasurementInstalling/Uninstalling Customization Software CustomizationConnection to the Computer Starting the Customization SoftwareMenu Items and Controls DownloadingCOM Port Drop Down List Close or File Close Ion ChambersFile Save AS and File Print Edit OK and Cancel Special ItemsDownload and Cancel 36. The Special Items Menu Calibration Temperature has focusMeasurement Displays Operators Manual Available Display Lines Display LineUsing the APPEND, DELETE, and Insert Buttons Display Line Group SelectionSelecting an Item and Placing It Changing a Line on a DisplayTimer Intervals 38. The Timer Intervals FormBias Settings 39. The Bias Settings FormExamples Changing the Pressure Units Customizing a Measurement DisplayAppending a Display Deleting a DisplayErrors Troubleshooting and Service TroubleshootingSymptom Display does not light up when Power is pressed Symptom ??Bias annunciator displayedSymptom HiBias annunciator displayed Symptom LoBias annunciator displayedSymptom Internal Reset Error displayed Symptom Configuration Error displayedBit Description Action Do not makeSymptom Current Overrange Displayed Symptom Dashes displayed instead of digitsSymptom Bias voltage measurement changes by one digit Measurements. ReturnExample 299.9 to Display Will Not Light Low Battery Hours? Is the battery voltage greater than 5.9 volts?Go to Bias ErrorLine Line Fuse Replacement Model 35040 Therapy Dosimeter Fuse ReplacementCleaning The Instrument Interface Connector CleaningReplaceable Parts Information Warranty Information Replaceable Parts ListRecalibration, Repair Information & Technical Assistance Replaceable Parts InformationBlank Sample Customization Reports Sample Documents35040 Appendix Sample Customization Reports 35040 Appendix Sample Customization Reports Blank Overview Introduction New FeaturesTimed Measurements Specifications Update Setup New Features BTimer Use Procedure Timer Setup ProcedureMaking Timed Exposure Measurements RESET/MEASURE Setup BADC ALC Automatic Leakage CompensationStart NA pA Stop Thres Current Operation Instructions BTimer Setup Decimal PlacesTable B-2. Measurement Indicators and Conditions Annunciators, Indicators, and Overrange ConditionsTable B-1. Annunciators Table B-3. Overrange Conditions Condition Overranged Measurement1Theory Of Operation Theory of OperationConfiguration Error Service Required Error Number Measurement Menu Main MenuMeasurement Displays 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
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