Agilent Technologies G6600-90006 manual Detector gases

Page 114

Table 5 Troubleshooting Detector Issues (continued)

Problem	Possible Cause	Diagnosis	Corrective Action

Low Response	Contaminated ceramic	If there does not appear to	Replace tubes.
	tubes.	be a leak, then the tubes
		should be inspected.
		Contamination can result
		from column bleed, samples
		which may contain volatile
		metal complexes, and large
		injections of coke forming
		hydrocarbons.

Wandering Baseline	Poor temperature control.	Monitor the temperature on
		the Controller. It should vary
		by no more than ±5 °C.

Check for a loose connection on the heating element or thermocouple. Reposition the thermocouple in the Burner.

Wandering Baseline	Contamination in one of the
	Detector gases.

Check the difference in the	Change Detector gases after
output signal between ozone	adding in-line traps.
on and off. The difference
should be between 0.2-2 mV
after equilibration.

Wandering Baseline	Leak in the oxidizer line at
	the oxidizer inlet connection.
	Leak at weld of H2 inlet
	fitting.

If using SCD, use a microliter syringe containing a small amount of sulfur compound e.g., CS2 to “snoop” for leaks while watching mV output. Leaks are very evident by a large increase in signal displayed on the LED.

Reseat air line into air inlet nut, or replace.

Tailing Peaks with	Severe contamination of	High background signal with	Avoid “house” gases,
Non-Equimolar Response	Detector gases.	respect to ozone off.	especially air from
			compressors. Clean gases
			should be used with
			appropriate traps.

Tailing Peaks	Poor column connection.	Verify column position at	Reinstall column.
		inlet and outlet. Look for
		discoloration of column at
		Detector side which
		indicates column in
		combustion zone.

Tailing Peaks	Cracked tubes.	Confirm pressure and	Replace tubes as needed.
		vacuum ranges. Inspect
		columns and ferrules.

Controller Reads >1000 °C	Thermocouple open.	Check electrical resistance	Replace thermocouple.
		between thermocouple pins.

114	Operation and Maintenance Manual

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Contents Operation and Maintenance Manual Acknowledgements WarrantySafety Notices Manual Part NumberEnglish WA R N I N GIs not in use Español Français Deutsch Italiano Dutch Veiligheidsvoorzieningen niet meerFollowing symbols are used on the equipment Contents Installation OverviewFront Panel Controls and Initial Startup OperationMaintenance Pump MaintenanceTroubleshooting IndexOperation and Maintenance Manual Introduction Operation and Maintenance Manual System Description Specifications Technical Information 355 SCDTechnical Information 255 NCD Physical Specifications Power requirementsVoltage Theory of Operation Sulfur Chemiluminescence DetectorNitrogen Chemiluminescence Detector Dual Plasma Controller Dual Plasma Burner with the 355 SCDDescription of Major Components Dual Plasma BurnerCross-Section of the Dual Plasma Burner for the 355 SCD Cross-Section of the Dual Plasma Burner for the 255 NCD Ozone Generator Chemiluminescence Reaction Cell and Photomultiplier Tube355 SCD Left Side 355 SCD Right Side 255 NCD Left Side View Pressure Transducer Vacuum PumpFID Adapter Optional Chemical TrapOil Coalescing Filter NCD Reaction CellNCD Photomultiplier Tube and Cooler Schematic for 355 SCD Schematic for 255 NCD, in Nitrogen Mode Schematic for 255 NCD, in Nitrosamine Mode Operation and Maintenance Manual Installation Overview Power Requirements Selecting a LocationEnvironmental Considerations Combustion Gas RequirementsTwo-stage pressure regulators Venting Gases Required Installation Tools Unpack and Inspect the InstrumentSet Up the Vacuum Pump Installing the Edwards RV5 Pump Oil-Sealed Vacuum PumpWA R N I N G Ard RV5 Oil-Sealed Vacuum Pump and Associated Traps Front Side RV5 Oil- Sealed Vacuum Pump and Associated Traps Top Setting the Gas Ballast Position RV5 Installing the Welch Dry Piston Vacuum Pump Operation Notes Welch Pump Welch Dry Piston Pump Operation and Maintenance Manual Connect the Power Cord SCD 230 V Unit Rear Panel DiagramInstall the Dry Compressed Air or O2 Supply Install the Signal Output Cables Install the Dual Plasma Burner Additional informationInstall the Dual Plasma Controller Dual Plasma Controller Rear PanelInstall Column Connections Capillary ColumnsPacked Columns and Columns with an Outside Diameter 0.8 mm Install the Transfer Line Front Panel Controls and Initial Startup Power Controls Detector Front Panel ControlsSignal Controls Display Output ControlsDual Plasma Controller Controls Dual Plasma Controller Front PanelInitial Startup Vacuum TestRecorder Test Detector Interface Setup Initial CheckoutIgnition Operation Start-Up Procedure Column Bleed Detector OperationDetector Stability and Response CokingContaminated Gases Fluctuating PressuresTypical Operating Conditions Typical Operating ConditionsDetection Limits Expected Detection Limits for Chromatographic ConditionsInstrument Shut-Down Daily ShutdownComplete Shutdown Using the 255 NCD in Nitrosamine Mode Special Operating ModesOperation and Maintenance Manual Operation and Maintenance Manual Maintenance Pump Maintenance Operating Life of Components for Edwards RV5 Vacuum PumpCleaning the Detector Changing the Oil Mist Filter RV5 Reaction Cell Cleaning EquipmentReaction Cell, PMT Housing and PMT Socket WA R N I N G Flow Sensor Calibration Detector Sensitivity MDLSCD Proper Ferrule Orientation to the Large Ceramic Tube Orientation of the Double Taper Ferrule Tightening the Heater Swivel Nut Operation and Maintenance Manual NCD Proper Ferrule Orientation to the Large Quartz Tube Burner Assembly Detail Tube Replacement for the SCD Positioning the Upper Tube in the Union Fitting 100 Operation and Maintenance Manual Operation and Maintenance Manual 101 Tube Replacement for the NCD Operation and Maintenance Manual 103 NCD Tube Replacement Detail Troubleshooting Solving Detector Problems Vacuum Pump Fuse Power ProblemsDetector Fuse Dual Plasma Controller FusesFuse Positions on the Power Supply Board Ozone Generation Problems High Voltage TransformerPlugged Restrictor Lines Response Problems Temperature Reading Problems Diagnosing General Problems Troubleshooting Detector IssuesDetector gases Troubleshooting Pump Issues Troubleshooting Burner Issues Index Agilent Technologies, Inc