Teledyne M5000B operating instructions TeledyneAnalyticalInstruments4-11

Page 79

Operations/Analysis Unit 4

optical filters. These optical filters are stable and are chosen to indicate the measured component at the required instrument wavelengths. Therefore, future, faster, yet much simpler calibration zero and span checks can be made without the unnecessary tedious on-line calibration described above nor the consumption of expensive calibration fluids which may be difficult to handle or obtain, are unstable, or toxic in nature.

A Fitter(s) at the factory is chosen and installed in the instrument (approxi- mating in absorbance value to the anticipated stream composition back- ground) to give reproducible zero/ span value when nitrogen or air back- ground is in the measuring cell. This capability is possible when the zero offset between the process fluid and dry air or nitrogen remains close to the zero point of the actual process fluid (i.e., after calibration, the zero off-set can be adjusted over the entire range of the meter, plus or minus 100 % from zero). In the case of the calibration zero check value, the requirement for installing a zero optical flag with dry nitrogen as the background fluid depends upon how unbalanced the reference and measure channel peak heights are with respect to each other as measured using an oscilloscope at Test Point 1 (TP1 -Violet)) of the AGC- board designated B-1 4521-4. A good ratio (ref/meas.) estimate to keep within is (1 volt minimum: 2 volt maximum) to (2 volt maximum: 1 volt minimum) between the zero process fluid signal levels and the nitrogen calibration fluid background signal levels. With the process fluid in the cell at the zero point of the calibration range, the reference and measure pulses are optically balanced using density screens placed over the reference and/or measure filters. These signals are balanced to 9 volts each as measured at TP4 (ref-orange) and TP3 (meas- yellow) on the PEAK LEVEL DETECTOR BOARD designated B- 14074-

A.The spectral background absorbance at the reference versus measure wavelengths of the process fluid determines the magnitude of the unbal- anced ref/meas ratio. This ratio is kept within the 1:2 to 2:1 values for proper operation of the AGC circuitry and therefore proper stability and signal/noise levels of the instrument output. After balancing on a zero sample of the process fluid, if the ratio is not found to be within the 1:2 to 2:1 range, a zero flag is necessary and installed in the sample cell compartment along with a span flag if ordered. This zero flag when chosen is also solenoid actuated to bring the ratio within the 1:2 to 2:1 range between process zero fluid and zero nitrogen or dry air background. The span flag is actuated while the zero offset level (usually when nitrogen is used as a zero calibration fluid) is switched in.

Zero calibration check after process on-line calibration.

To check zero on the analyzer, immediately back-flush out the process fluid and dry the cell out with a reproducible zero fluid that should never contain any of the analyte. (This is usually done with N2 assuming the process fluid has low vapor pressure and can be purged dry in an acceptable short time

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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 ReplacementAnalog System Self Diagnostic TestMaintenance Model 5000B Photometric Analyzer PowerCell detector PreampPart Part II Analysis Unit Part IIRoutine Maintenance Part II Analysis Unit Appendix Iv Part Operations/Analysis Unit Explosion-ProofVersionControlModule Control FunctionsAnalyzers not equipped with Auto Zero Control SettingsStart-p PreliminaryInspectionPre-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 Automatic operation and routine operational duties Routine MaintenancePart II Maintenance/Analysis Unit System Visual Check and Response ProcedureDaily 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
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