Hach 3650 manual Taking Measurements, Preconditioning Sensor

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3650 Portable O2 Analyzer - Operating Information

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2.2 Taking Measurements

Once the system is calibrated, you should be able to begin taking measurements. Connect the top-mounted inlet to accept your sample, typically this is accomplished by connection to a sampling valve. The sample flow can be regulated by the knurled stainless steel knob on top of the flow chamber.

Minimum flow rates, measurement limits and response times for the various available membranes are given in the accompanying EC Sensors - Maintenance & Installation Manual.

The LCD includes a right-side marker to distinguish between gas concentration measurements and temperature. This marker also indicates the measurement display units (ppm, ppb or % depending on the instrument model).

To switch between gas measurement and temperature measurement, press the Up/ Down Arrow buttons.

To backlight the LCD for approximately three minutes, press the Backlight button.

Note:

For measurements of gaseous samples in % units, you must open the barometric pressure sensor relief valve switch on the top of the instrument from time to time, to allow the pressure inside the instrument to equilibrate to the barometric pressure.

2.2.1 Preconditioning Sensor

You can expect a more rapid and accurate first result if you precondition the sensor before you take readings.

To precondition, connect the flow chamber to a convenient sampling source at or below expected O2 levels. If measurements take place in carbonated samples, precondition with a carbonated beverage or carbonated water. Open the sampling valve on the flow chamber, just enough for a trickle. Then, switch on the instrument and watch the LCD. You will see the values drop.

If you are measuring in the 0.1 ppm range, then only a short time is required for the display to fall to this level, whereas ppb level measurements may require the sensor to remain exposed to the sample for half an hour or more. You will establish your own requirement with experience. Once the LCD displays the expected level of O2, close off the sample. The sensor is now preconditioned and ready to use.

You may want to precondition prior to each series of measurements, depending on frequency of use.

Operator Manual

ORBISPHERE

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Contents Operator Manual Page Product Recycling Information Orbisphere Following only applies to European customers Product DisposalMarking Restriction of Hazardous SubstancesTable of Contents Specifications Accessories and Attachments Maintenance and TroubleshootingCalibrations Part ListsManual Overview Safety Conventions Safety PrecautionsAbout this Manual Revision HistoryService and Repairs Safety RecommendationsAcknowledgements Precautionary LabelsOrbisphere Installation Flow Chamber Installation Sensor InstallationExternal Power optional WinLog97 PC Program InstallationSample Tube Adapter optional ConnectionsInstrument PC Connection Instrument Clock Setting Installation Completion Check ListBatteries Electrochemical SensorFlow Chamber Storage When not UsedOperating Controls Operating InformationOperating Information 3650 Portable O2 Analyzer Preconditioning Sensor Taking MeasurementsAutomatic Data Acquisition Storing Measurements In the InstrumentManual Data Acquisition Storing and Accessing Measurements From the PC Viewing Stored MeasurementsDownloading Stored Values Copying Values Altering the Sampling Point DescriptionsSaving Values Printing ValuesClearing Stored Values Timebase Updating Rate Maximum Samples 10 divisions Monitoring Measurements In Real-TimeOrbisphere Main Menu Basics Options SetupWinlog97 Export Menu O2 Analyzer PC Connection Reviewing Instrument ConfigurationConfiguring the Instrument Automatic Data Acquisition Setting Sampling IntervalsMembrane Selection Select from the PC Selecting Type of CalibrationLocking Out the Instrument’s CAL Button Sensor Calibration Range CheckingEntering a Span Gas Value Change from the PC Dual Use model 3650/113 onlyOrbisphere Pressure Calibration CalibrationsCalibration In a Span Gas Sensor CalibrationCalibration In Line Calibration In Air Calibration Range CheckingAccessories and Attachments Accessories and Attachments 3650 Portable O2 Analyzer Maintenance Maintenance and TroubleshootingInstrument Batteries SensorTroubleshooting Serial TestKeyboard Test Display Test Clock SettingsMeasurements View Analog Voltages ViewSystem Specifications SpecificationsGeneral Technical Data Instrument Display OptionsTheory of Operation Accessories Part ListsInstrument Spare Parts Appendix a Glossary Common UnitsTerms and Definitions Glossary 3650 Portable O2 Analyzer Tables and Illustrations AnnexAnnex 3650 Portable O2 Analyzer User Notes