Teledyne M5000B operating instructions Operations/Analysis Unit Operational Theory Contd

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Operations/Analysis Unit 4

4.4Operational Theory Cont'd

The energy source for the analyzer is most commonly provided by as a high intensity quartz iodine lamp located in the source module. Quartz iodine was chosen because it produces sufficient NIR to operate the system and maintains a nearly constant brightness over its lifetime. (See Figures 2-1 and 2.2).

This energy is then fed through the sample, which is temperature controlled, and into the detector module where it passes through a rotating filter wheel before reaching the lead sulfide (PbS) detector (PbSe also used for longer wavelengths (cooled and non-cooled).

The filter wheel, driven at 30 RPS or 1800 RPM by a synchronous AC motor, contains two optical filters with bandpasses selected for each applica- tion, thus providing reference and measuring pulses from which the required information may be obtained.

The detector receives pulses at the rate of 60 PPS, or two pulses per revolution of the filter wheel. Every other pulse is from the measuring filter, while the alternate pulse is from the reference filter, so that pulses through the measuring filter alternate with pulses through the reference filter. A filter position sensor, which is an optical device having an integral light source and light detector, differentiates between the two.

The two entrained pulses received by the detector each revolution are amplified through a preamplifier which is physically located inside the sealed compartment with the filter wheel and detector. This signal is then sent to a clamping circuit where an exact zero reference is established.

This clamped video signal is then fed through a gain control network, which is controlled by the automatic gain control loop, through another amplifier, to the electronic switch. This switch is controlled by the switch driver network which derives its information from the filter position sensor in order to separate the entrained video signal into its component parts of a measuring peak and a reference peak. These peaks are then fed through a balancing network and channeled into separate peak height detectors which produce DC voltage levels which are exactly equal to the peak height or absolute magnitude of the voltage from the base to the peak of each of the pulses.

At this point the reference signal is fed back to the automatic gain control loop to maintain the desired system gain. In addition, both the mea- suring and reference levels are fed to selector switches in order to enable

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Contents Teledyne Analytical Instruments Photometric AnalyzerCopyright 1999 Teledyne Analytical Instruments Model 5000BIii Table of ContentsModel 5000B Teledyne Analytical Instruments Part I Control Unit Part IIi Part InstallationOperation Maintenance Model 5000B Photometric Analyzer Iv PartTypical Applications OverviewPhotometric Analyzer Part I Control Unit Introduction Model 5000B Other NIR Absorbers that can be measured consult factory Introduction Model 5000B Main Features of the Analyzer ESCAPE/ENTER Switch 1 UP/DOWN SwitchOperator Interface Model 5000B Controls, Indicators, and Connectors Control Section Interface Panel Model 5000B Interface Panel Introduction Model 5000B Unpacking the Control/Analysis Unit InstallationPart 115VAC Primary Input Power ConnectionsAnalog Output Connections ExamplesRange Voltage Current mA Alarm RelaysTypes of Relay Contacts The connectors are Part I RS-232 Sig RS-232 Pin Purpose RS-232 SignalsCommand Description Testing the SystemParameter Setting Part Photometric Analyzer Operation /Control Unit OperationOperation/Control Unit Hierarchy of System Functions and Subfunctions System Function Setting up an AUTO-CALSelect More and press the Enter Key Entering the Password PasswordProtectionInstalling or Changing the Password Logging Out System Self-Diagnostic Test CheckingLinearitywithALGORITHM Model ScreenSetting 90% Response time seconds Digital Filter SetupFilter or Solenoid Setup Calibration/Hold Timer Setup Hold/Track SetupAnalog 4 to 20 mA Output Calibration Calbrt hold 3 min Sample hold 1 minModel Use UP/DOWN arrow to Adjust 4 ma 250Show Negative Auto Mode ZeroingZero Cal Manual Mode Zeroing Sccm Cell FailureManual Mode Spanning Auto Mode SpanningSpan Cal Offset Function How to access the offset functionZero off 0.0 ppm ENT to begin Zero Select zero mode Auto Select zero mode MANAlarms Function AL1 1ØØØ ppm HI DftN FsN LtchN Manual Select/Define Range Screen Range Select FunctionAuto Screen Precautions 2illustratestheseschemesgraphically Analyze Function Set Range Screen Algorithm Application More Curve Algorithm Screen Auto Mode Linearization Part I Control Unit/Analysis Unit Maintenance Fuse ReplacementMaintenance Model 5000B Photometric Analyzer System Self Diagnostic TestPower AnalogCell detector PreampPart Part II Analysis Unit Part IIRoutine Maintenance Part II Analysis Unit Appendix Iv Part Operations/Analysis Unit Explosion-ProofVersionControlModule Control FunctionsStart-p Control SettingsPreliminaryInspection Analyzers not equipped with Auto ZeroPre-Start-upElectricalCheckout Power On ObservationsTeledyneAnalyticalInstruments4-5 Calibration ProcedureStandardizationFluids TeledyneAnalyticalInstruments4-7 Operations/Analysis Unit TeledyneAnalyticalInstruments4-9 Operations/Analysis Unit TeledyneAnalyticalInstruments4-11 Operations/Analysis Unit TeledyneAnalyticalInstruments4-13 Ppm simulated water using Sample Span ZeroAttachment 5000B/5020 NIR Analyzer Operations/Analysis Unit Operational Theory Contd Source Module Sample cell OpticalSystemAnalyzerSystem-BlockDiagram Power Module Block Diagram Detectorcompartment Part II Maintenance/Analysis Unit Routine MaintenanceSystem Visual Check and Response Procedure Automatic operation and routine operational dutiesDaily Suggested Preventive Maintenance ScheduleEquipment Required Oscilloscope Display of the I to E Converter Output Part II Maintenance/Analysis Unit Inverting Amplifier Setup of the Logarithmic AmplifierInterface Board Terminals Strip Battery-Powered Oscilloscope Synchronization PointPart Part II Maintenance/Analysis Unit Part Operating Temperature 0-50oC SpecificationsPhotometric Analyzer, 5000B Appendix Appendix Models 5000B Other Features QtyP/NDescription Recommended 2-Year Spare Parts ListDrawing List, 5000B Appendix Models 5000B Teledyne Analytical Instruments