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Agilent Technologies 6890N, Troubleshooting Manual

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Agilent Technologies 6890N Troubleshooting Manual Download Page 29

Chromatographic Symptoms

3

Troubleshooting

29

Peak Tailing

The figure below shows an example of tailing peaks. When 
troubleshooting tailing peaks, consider: 

•

Which peaks are tailing?

•

Are the tailing peaks active compounds, all compounds, or 
are there trends (such as early eluters or late eluters)?

•

Check the column for severe contamination.

•

Consider the column stationary phase (active column).

•

Verify that the column was cut and installed properly.

•

Consider the type of adapter, liner, and inlet seal being used. 
One or all of these may be contaminated or active.

•

Check adapters (if installed) and liner for solid particles. 

•

For capillary splitless injection, consider compatibility 
between the solvent and column.

•

Verify that the injection technique is adequate. 

•

Verify the inlet temperature.

•

Check for dead volume in the system. Check for correct 
column installation at both ends.

•

Inspect any transfer lines for cold spots. 

NPD 

For NPD, do the following:

•

Verify that you are using the correct bead for the sample 
being run. If you are analyzing phosphorus, install a black 
bead. White beads can cause peak tailing when phosphorus 
is being analyzed.

•

Verify that the correct jet is installed. Use an extended jet.

•

Replace the ceramic insulators.

Summary of Contents for 6890N

Page 1: ...Agilent Technologies Agilent 6890N Gas Chromatograph Troubleshooting ...

Page 2: ...itness for a par ticular purpose Agilent shall not be liable for errors or for incidental or consequential damages in connection with the furnishing use or perfor mance of this document or of any information contained herein Should Agilent and the user have a separate written agreement with warranty terms covering the material in this document that conflict with these terms the warranty terms in t...

Page 3: ...ge Needle Bends During Injection into Inlet 14 FID Does Not Ignite 15 FID Ignitor Does Not Glow During Ignition Sequence 16 Corrosion in FID Collector and Ignitor Glow Plug 17 FPD Does Not Ignite 18 NPD Adjust Offset Process Fails 19 3 Chromatographic Symptoms Retention Times Not Repeatable 22 Peak Areas Not Repeatable 23 Contamination or Carryover 24 Isolate the source 24 Check possible causes al...

Page 4: ...he correct jet Low Peak Area or Height 36 FID Flame Goes Out During a Run and Attempts to Reignite 38 FID Baseline Output Above 20 pA 39 FPD Flame Goes Out During a Run and Attempts to Reignite 40 FPD Output Too High or Too Low 41 FPD Low Peak Areas 42 FPD Large Peak Width at Half Height 43 FPD Baseline Output High 20 pA 44 NPD Solvent Quenching 45 NPD Response Low 46 NPD Baseline Output 8 million...

Page 5: ...nitor Does Not Glow During Injection Sequence 66 NPD Adjust Offset Process Fails 67 FPD Does Not Ignite 68 5 Shutdown Symptoms Column Shutdown 70 Hydrogen Shutdown 71 Thermal Shutdowns 72 6 Nonfunctional GC Symptoms GC Does Not Turn On 74 PC Cannot Communicate with GC 75 7 Checking for Leaks Leak Check Tips 78 To Check for External Leaks 79 To Check for GC Leaks 81 Leaks in Capillary Flow Microflu...

Page 6: ...erify That the FID Flame Is Lit 94 To Verify FID Ignitor Function During Ignition Sequence 95 To Measure FID Leakage Current 96 To Measure FID Baseline Output 97 To Measure NPD Leakage Current 98 To Verify That the NPD Bead Is Ignited 99 To Verify That the FPD Flame Is Lit 100 To Adjust the FPD Lit Offset 101 ...

Page 7: ...ent 6890N Gas Chromatograph Troubleshooting Agilent Technologies 1 Concepts and General Tasks Concepts 8 Configurable Items to Always Keep Current 9 Information to Obtain Before Calling Agilent for Service 10 ...

Page 8: ...l also includes common troubleshooting tasks as well as information needed prior to calling Agilent for service How to troubleshoot using this manual Use the following steps as a general approach to troubleshooting 1 Observe the symptoms of the problem 2 Look up the symptoms in this manual using the Table of Contents or the Search tool Review the list of possible causes of the symptom 3 Check each...

Page 9: ...tering a column causes incorrect flows changed or incorrect split ratios retention time changes and peak shifts Automatic Liquid Sampler configuration Keep the Automatic Liquid Sampler ALS configuration up to date to ensure proper operation ALS items to keep current include injector position installed syringe size and solvent and waste bottle usage Gas configuration Reconfigure the GC every time t...

Page 10: ...dware installed and parameters configuration when the error occurred sample supply gas type gas flow rates detectors inlets installed and so forth Any messages that appear on the GC display Results of any troubleshooting tests you have run Press the Status key to display previous Error Not Ready and Shutdown messages To obtain service support contact numbers see the Agilent Web site at www agilent...

Page 11: ...h Troubleshooting Agilent Technologies 2 Hardware Symptoms Plunger Errors 12 Vial Mishandled by ALS 13 Syringe Needle Bends During Injection into Inlet 14 FID Does Not Ignite 15 FPD Does Not Ignite 18 NPD Adjust Offset Process Fails 19 ...

Page 12: ...shooting 2 Hardware Symptoms Plunger Errors If the ALS reports a front or back plunger error check the following possible causes The syringe plunger is sticking or is not securely connected to the plunger carrier ...

Page 13: ...When you find a mishandled sample vial do the following Check for folds or wrinkles in the crimp cap especially near the neck of the sample vial Use Agilent recommended sample vials Check sample labels if applicable Check that they are the correct size Verify that the labels do not interfere with the gripper Check that the tray quadrants are clean and snapped into the tray base ...

Page 14: ...correctly into the syringe carriage Check that the needle support and guide are clean Remove any residue or septum deposits If using the cool on column inlet check that the correct insert for the syringe is installed Check that you are using the proper syringe The combined length of the syringe barrel and needle should be approximately 126 5 mm WARNING When troubleshooting the injector keep your h...

Page 15: ...tly impacts ignition Nonoptimal flow settings can prevent flame ignition See To Measure a Detector Flow There could be a large leak in the system if the flame still will not light Large leaks result in measured flow rates being different from actual flow rates causing nonideal ignition conditions Thoroughly leak check the whole system especially the column fitting at the FID Check the column flow ...

Page 16: ...50 C Agilent recommends operating the FID at 300 C The ignitor is not making a good connection to the ground The ignitor must be tightly screwed into the FID castle assembly The three T 20 Torx screws that hold the collector assembly in place must be tight The brass knurled nut that holds the FID castle assembly in place must be tight Perform FID maintenance if these parts are corroded or oxidized...

Page 17: ...pecting the collector and ignitor glow plug for corrosion while performing maintenance on the FID The FID combustion process results in condensation This condensation combined with chlorinated solvents or samples causes corrosion and sensitivity loss To avoid corrosion keep the detector temperature above 100 C ...

Page 18: ...tector Check that the FPD ignitor operates See To Verify That the FPD Flame Is Lit Check the column and makeup flow rates Ensure that condensation in the vent tube is not dripping back into the detector The flexible plastic vent tube must run from the detector into a container without sagging in order to properly drain water condensate Keep the open tube end out of the water in the container Check...

Page 19: ... clogged Measure the actual detector flows See To Measure a Detector Flow Check the condition of the bead Replace if necessary Verify that the flow settings are correct Thoroughly leak check the whole system especially the detector column fitting See Checking for Leaks Set the equilibration time to 0 0 ...

Page 20: ...20 Troubleshooting 2 Hardware Symptoms ...

Page 21: ...Including Wander Drift and Baseline Spikes 33 Check for the correct jet Low Peak Area or Height 36 FID Flame Goes Out During a Run and Attempts to Reignite 38 FID Baseline Output Above 20 pA 39 FPD Flame Goes Out During a Run and Attempts to Reignite 40 FPD Output Too High or Too Low 41 FPD Low Peak Areas 42 FPD Large Peak Width at Half Height 43 FPD Baseline Output High 20 pA 44 NPD Solvent Quenc...

Page 22: ...elivered to the GC must be at least 40 kPa 10 psi greater than the maximum inlet pressure required at final oven temperature Run replicates of known standards to verify the problem Check for leaks at the inlet See Leak Check Tips Verify that you are using the correct liner type for the sample being injected Consider if this is this first run Has the GC stabilized If using an FID or NPD and retenti...

Page 23: ...of the 7683B Automatic Liquid Sampler Installation Operation and Maintenance manual Replace the syringe Check for leaks in the inlet liner as applicable and column connection See Checking for Leaks Check sample level in vials Run replicates of known standards to verify the problem Consider if this is this first run Has the GC stabilized ...

Page 24: ...combinations Check the septum type and installation Perform complete inlet maintenance Replace all consumable parts and bake out the inlet Perform column maintenance Bake out contaminants remove the contaminated length of column near the inlet and reverse and bake out the column as needed Check for sample carryover from previous runs Make several no injection blank runs and see if the ghost peaks ...

Page 25: ...ns See Configurable Items to Always Keep Current Check the autosampler injection volume Check the vial caps Check configured syringe size Some syringe sizes are specified at half capacity If the maximum syringe volume is marked at half height on the barrel not at the top of the barrel enter twice the labeled volume when configuring the syringe size ...

Page 26: ...he detector in use is assigned to a signal Check the column for proper installation Ensure that the column is not plugged See To Measure a Column Flow Perform column maintenance Check for leaks See Checking for Leaks Check the flow settings then measure the actual detector flows See To Measure a Detector Flow If the problem is with the detector see Table 1 Table 1 Detector troubleshooting Detector...

Page 27: ...r or date Make solvent blank runs to evaluate baseline without sample Make no injection blank runs remove the syringe from the injector and start a run to evaluate baseline without solvent Check for contamination See Contamination or Carryover Consider the effect of column film thickness on bleed Check for leaks at the column fittings See Checking for Leaks Prepare and use a column compensation pr...

Page 28: ...city Install and use deactivated consumable parts in the inlet for example a liner Perform column maintenance Bake out contaminants remove the contaminated length of column near the inlet and reverse and bake out the column as needed Check column installation at both ends Select a higher resolution column ...

Page 29: ...all of these may be contaminated or active Check adapters if installed and liner for solid particles For capillary splitless injection consider compatibility between the solvent and column Verify that the injection technique is adequate Verify the inlet temperature Check for dead volume in the system Check for correct column installation at both ends Inspect any transfer lines for cold spots NPD F...

Page 30: ...or any inlet operating in split mode with any detector Check liner type Increase the inlet temperature and verify that the insulation cup is installed and contains insulation Check column cut and installation into the inlet See the topic for the SS PTV and VI For any inlet operating in splitless mode with any detector Check the inlet for leaks See Checking for Leaks Check liner type Verify that th...

Page 31: ... and bake out the inlet Install a deactivated liner SS PP and PTV inlets Check for leaks at the septum liner and column fittings See Checking for Leaks Install an Agilent Direct Connect liner Use a pulsed pressure method for quicker sample transfer to column Bake out the inlet See the following To Bakeout Contaminants from the Split Splitless Inlet To Bakeout Contaminants from the Purged Packed In...

Page 32: ...ding occurs try the following Verify that the injection volume is appropriate Ensure that the column is installed properly Verify that the appropriate injection technique is being used If using capillary splitless injection consider the compound solubility in the injection solvent Change the solvent Use a retention gap Check purity of sample solvent Symmetrical Fronting Overloaded ...

Page 33: ... of the chromatographic peaks Noisy baseline A noisy baseline or high detector output can indicate leaks contamination or electrical problems Some noise is inevitable with any detector although high attenuations can mask it Since noise limits useful detector sensitivity it should be minimized For all detectors check for leaks at the column fittings See Checking for Leaks For the FID see To Measure...

Page 34: ...led too high into detector Oven temperature exceeds column maximum recommended temperatures Baseline wander and drift Baseline wander or drift can occur when a flow or temperature setting is changed If the system has not stabilized at the new conditions before it starts a run some baseline changes are to be expected If experiencing baseline wander check for leaks especially at the septum and at th...

Page 35: ...nces in the lab Figure 2 Random spiking Spikes are isolated baseline disturbances usually appearing as sudden and large upscale movements If accompanied by noise resolve the noise problem first since spiking may disappear at the same time Check for a contaminated detector For a packed column check that the packed column exit is properly sealed with glass wool Check packed column installation ...

Page 36: ...ple Verify that the detector flow settings are correct Check the supply gas purity Check all trap indicators and dates Verify that the method parameters are correct Check sample stability Check configured syringe size Some syringe sizes are specified at half capacity If the maximum syringe volume is marked at half height on the barrel not at the top of the barrel enter twice the labeled volume whe...

Page 37: ...Chromatographic Symptoms 3 Troubleshooting 37 Check that the correct filter is installed and is clean Check the flow rates Check the makeup gas type ...

Page 38: ...e Check for a plugged jet Verify that the gas flow settings are correct Verify that Lit offset is set appropriately If the FID flame attempts to reignite but is already lit do the following Verify that the FID Lit offset setting is appropriate for the run typically 2 0 pA Check to see if an aromatic peak or water extinguished the flame Check for a partially plugged jet Measure actual hydrogen air ...

Page 39: ...gas supply Inspect the column for column bleed Check the gas supply trap indicators dates and ensure that the traps are not expended Verify that the detector was reassembled properly after recent maintenance Inspect the detector for contamination Check that the FID leakage current is 2 0 pA See To Measure FID Leakage Current ...

Page 40: ...tion in the vent tube is not dripping back into the detector The flexible plastic vent tube must run from the detector into a container without sagging in order to properly drain water condensate Keep the open tube end out of the water in the container If the FPD flame goes out and then reignites do the following Verify that the Lit offset setting is lower than the normal baseline Check for leaks ...

Page 41: ... Too High or Too Low Verify that the correct filter is being used Do not use a phosphorus filter with sulfur optimized flows or a sulfur filter with phosphorus optimized flows Check the position of the column as installed in the detector Check the gas purity ...

Page 42: ...e parts and bake out the inlet Perform column maintenance Bake out contaminants remove the contaminated length of column near the inlet and reverse and bake out the column as needed Verify that the column is installed properly Consider the filter type sulfur or phosphorus Check the system for leaks See Checking for Leaks Verify that the method settings are appropriate Check the flow rates Check th...

Page 43: ...ng 43 FPD Large Peak Width at Half Height If the FPD produces peaks that are abnormally wide at half the peak height do the following Check the actual injection volume reduce if necessary Verify that the liner is not reacting with the sample ...

Page 44: ...y Check all trap indicators and dates Check the detector for contamination Check for light leaks at the photomultiplier tube PMT tighten the PMT if it is loose Perform complete inlet maintenance Replace all consumable parts and bake out the inlet Perform column maintenance Bake out contaminants as needed ...

Page 45: ...a solvent peak try the following Turn hydrogren off on around the solvent peak Use nitrogen as the makeup gas Set the total column flow and makeup gas to less than 10 mL min Increase the air flow by 10 mL min Increase the detector temperature to 325 C Implement an Agilent Dean s switch solvent vent solution ...

Page 46: ... needed Verify correct column installation A large concentration of solvent has extinguished the hydrogen air plasma Increase the bead voltage Measure the actual gas flow at the detector See To Measure a Detector Flow Check for a partially plugged jet Verify that the bead is activated Look through the vent hole on the detector lid to see if the bead is glowing orange Replace the insulators collect...

Page 47: ...Chromatographic Symptoms 3 Troubleshooting 47 NPD Baseline Output 8 million The collector is shorted to the detector housing Disassemble the collector and insulators and reinstall ...

Page 48: ... see if it is clogged Measure the actual detector flows See To Measure a Detector Flow Check the condition of the bead Replace if necessary Verify that the flow settings are correct Thoroughly leak check the whole system especially the detector column fitting See Checking for Leaks Set the equilibration time to 0 0 ...

Page 49: ...c Symptoms 3 Troubleshooting 49 NPD Low Selectivity Verify that the hydrogen flow is correct 3 mL min Inspect the bead it may be defective or expended Verify correct bead voltage Replace the collector and insulators ...

Page 50: ...TCD Verify that the correct gas type is being used Check for a leak in the system especially at the detector column fitting See Checking for Leaks Consider sensitivity to analytes Check the flow settings then measure the actual detector flows See To Measure a Detector Flow ...

Page 51: ...hromatographic Symptoms 3 Troubleshooting 51 TCD Baseline Has Dampened Sinusoidal Noise Trailing Peaks Ringing Baseline Wrong data rate is selected in the data system For TCD the data rate should be 5 Hz ...

Page 52: ... Troubleshooting 3 Chromatographic Symptoms TCD Peaks Have Negative Dip on Tail Check for leaks at the detector column adapter fitting See Checking for Leaks Upgrade the detector to a passivated filament ...

Page 53: ...ow 60 A Gas Exceeds Pressure Setpoint or Flow 61 The Inlet Pressure or Flow Fluctuates 62 Cannot Maintain a Pressure as Low as the Setpoint on a Split Inlet 63 The Measured Column Flow Does Not Equal the Displayed Flow 64 FID Does Not Ignite 65 FID Ignitor Does Not Glow During Injection Sequence 66 NPD Adjust Offset Process Fails 67 FPD Does Not Ignite 68 This section includes faults and symptoms ...

Page 54: ... component key for example Front inlet to see which setpoints or conditions are not ready Check for a sampler problem Check for a data system problem If performing manual injections in splitless or gas saver mode you may need to press Prep Run to prepare the inlet for the injection Do this for example To toggle the inlet purge valve before a splitless injection To prepare for a pulsed injection To...

Page 55: ... flow never becomes ready check for the following Check the supply gas for sufficient delivery pressure Check the configured gas type The configured gas type must match the actual gas plumbed to the GC Check for leaks in the gas delivery plumbing and the GC See Checking for Leaks ...

Page 56: ...erify that the oven flaps in the back of the GC are open Listen to verify that the fan is operating The figure below illustrates the location of the two oven flaps If the flaps are not operating smoothly contact Agilent for service If using cryo cooling Check for sufficient cryo coolant Check if operating limits are exceeded WARNING The exhaust coming from the back of the GC is very hot Keep hands...

Page 57: ...oven temperature by at least 20 degrees 2 Verify that the oven flaps in the back of the GC are closed The figure below illustrates the location of the two oven flaps If the flap is stuck open or if the flaps are closed and the oven still does not heat contact Agilent WARNING The exhaust coming from the back of the GC is very hot Keep hands and face away from the exhaust vent ...

Page 58: ...never becomes ready do the following Check for a missing insulation cup on an inlet or detector Check for a very large temperature difference between the oven and inlet or detector Check for missing insulation around the inlet or detector If using a cool on column with CryoBlast or a PTV inlet Check cryo coolant level Check if operating limits have been exceeded ...

Page 59: ...o the following Check the column mode Check that a capillary column is configured to the correct inlet Check the configured column dimensions Check that the flow is turned on If you cannot set a flow or pressure using the purged packed inlet do the following Check the column mode The packed inlet uses flow control for undefined columns Check that the flow is turned on ...

Page 60: ...upply delivery pressure The pressure at the supply should be at least 10 psi greater than the desired setpoint Check for leaks See Checking for Leaks If using gas saver be sure that the gas saver flow rate is high enough to maintain the highest column head pressure used during a run Check for an incorrectly installed column If you are using a split splitless inlet PTV inlet or volatiles interface ...

Page 61: ...g If using a split splitless inlet PTV inlet or volatiles interface Decrease the split ratio Replace the split vent filter Verify that the correct liner is selected for split splitless and PTV inlets Check the gold seal for contamination for split splitless inlet If using an FID or NPD Check for a plugged jet Valves Check for a misaligned rotor ...

Page 62: ...urifier or gas generator is operating at or near capacity Check the supply gas for sufficient delivery pressure Verify that the supply pressure regulator is functioning properly Check for leaks See Checking for Leaks Check for large restrictions in the inlet liner or split vent trap Verify that the correct liner is installed Check for a restriction in headspace purge and trap and any other externa...

Page 63: ...t on a Split Inlet If the GC cannot maintain a pressure as low as the setpoint check for the following Consider using a liner designed for split analysis Check for a plugged liner Check for contamination in the split vent line Contact Agilent service to replace if necessary Replace gold seal ...

Page 64: ...alculated flow displayed on the GC do the following Verify that the measured flows are corrected to 25 C and 1 atmosphere Verify that the correct column dimensions are configured accurately including the actual trimmed column length The split vent line or trap may be partly plugged creating an actual inlet pressure higher than the setpoint pressure ...

Page 65: ...eatly impacts ignition Nonoptimal flow settings can prevent flame ignition See To Measure a Detector Flow There could be a large leak in the system if the flame still will not light Large leaks result in measured flow rates being different from actual flow rates causing nonideal ignition conditions Thoroughly leak check the whole system especially the column fitting at the FID Check the column flo...

Page 66: ...o 150 C Agilent recommends operating the FID at 300 C The ignitor is not making a good connection to the ground The ignitor must be tightly screwed into the FID castle assembly The three T 20 Torx screws that hold the collector assembly in place must be tight The brass knurled nut that holds the FID castle assembly in place must be tight Perform FID maintenance if these parts are corroded or oxidi...

Page 67: ...is clogged Measure the actual detector flows See To Measure a Detector Flow Check the condition of the bead Replace if necessary Verify that the flow settings are correct Thoroughly leak check the whole system especially the detector column fitting See Checking for Leaks Set the equilibration time to 0 0 ...

Page 68: ...detector Check that the FPD ignitor operates See To Verify That the FPD Flame Is Lit Check the column and makeup flow rates Ensure that condensation in the vent tube is not dripping back into the detector The flexible plastic vent tube must run from the detector into a container without sagging in order to properly drain water condensate Keep the open tube end out of the water in the container Che...

Page 69: ...69 Agilent 6890N Gas Chromatograph Troubleshooting Agilent Technologies 5 Shutdown Symptoms Column Shutdown 70 Hydrogen Shutdown 71 Thermal Shutdowns 72 ...

Page 70: ... split splitless inlet would turn off All other heaters turn off When viewed their temperature parameters flash Off Attempts to turn on a shut down zone fail with an error message The instrument beeps To recover from this state 1 Fix the cause of the shutdown Check for a broken column Replace the inlet septum Replace the inlet O ring Check the supply pressure Check for leaks 2 Press the key for th...

Page 71: ...cluding any devices connected to the auxiliary heater controls such as valve box heaters and transfer line heaters When viewed these parameters will flash Off Sounds an alarm To recover from this state 1 Fix the cause of the shutdown Replace the inlet septum Replace the inlet O ring Check for broken column Check the supply pressure Check the system for leaks See Checking for Leaks 2 Press the key ...

Page 72: ...or another heated zone is not within its allowable temperature range lower than minimum temperature or higher than maximum temperature To recover from this state 1 Fix the cause of the shutdown Check for missing insulation 2 Most thermal shutdowns can be cleared by shutting off the thermal zone ...

Page 73: ...73 Agilent 6890N Gas Chromatograph Troubleshooting Agilent Technologies 6 Nonfunctional GC Symptoms GC Does Not Turn On 74 PC Cannot Communicate with GC 75 ...

Page 74: ... 6 Nonfunctional GC Symptoms GC Does Not Turn On If the GC does not turn on Check the power cord Check the building s power If the problem is at the GC turn off the GC power Wait 30 seconds then turn the on the GC power ...

Page 75: ...address For example if the IP address is 10 1 1 101 enter ping 10 1 1 101 If LAN communications are working properly you will see a successful reply For example If the ping test is successful check the software configuration If the ping test is unsuccessful do the following Check the LAN cabling Verify the IP address subnet mask and gateway addresses Check that a crossover cable for single GC to c...

Page 76: ...76 Troubleshooting 6 Nonfunctional GC Symptoms ...

Page 77: ...ent 6890N Gas Chromatograph Troubleshooting Agilent Technologies 7 Checking for Leaks Leak Check Tips 78 To Check for External Leaks 79 To Check for GC Leaks 81 Leaks in Capillary Flow Microfluidic Fittings 82 ...

Page 78: ...htening Swagelok and column fittings 2 Check any potential leak points associated with any maintenance recently performed 3 Check GC fittings and connections that undergo thermal cycling since thermal cycling tends to loosen some fitting types Use the electronic leak detector to determine if a fitting is leaking Start by checking any newly made connections first Remember to check connections in th...

Page 79: ...for External Leaks Check for leaks at these connections Gas supply bulkhead fittings Gas cylinder fitting Regulator fittings Traps Shut off valves T fittings Perform a pressure drop test 1 Turn off the GC 2 Set the regulator pressure to 415 kPa 60 psi ...

Page 80: ...3 Fully turn the regulator knob counterclockwise to shut the valve 4 Wait 5 min If there is a measurable drop in pressure there is a leak in the external connections No drop in pressure indicates that the external connections are not leaking ...

Page 81: ...e connections Inlet septum septum head liner split vent trap split vent trap line and purge vent fittings Column connections to inlets detectors valves splitters and unions Fittings from the flow modules to the inlets detectors and valves Column adapters Agilent capillary flow fittings ...

Page 82: ...eak usually indicates that the fitting has been overtightened Unless the fitting is obviously loose do not tighten it further Instead remove the connection trim the column end and install it again See To Attach a Capillary Column Using SilTite Metal Fittings Also inspect the plat and connection for a broken column tip ...

Page 83: ...ctor Flow 89 To Perform the GC Self Test 92 To Adjust the FID Lit Offset 93 To Verify That the FID Flame Is Lit 94 To Verify FID Ignitor Function During Ignition Sequence 95 To Measure FID Leakage Current 96 To Measure FID Baseline Output 97 To Measure NPD Leakage Current 98 To Verify That the NPD Bead Is Ignited 99 To Verify That the FPD Flame Is Lit 100 To Adjust the FPD Lit Offset 101 ...

Page 84: ...660 is supplied for the FID Insert the adapter into the detector exhaust vent as far as possible You will feel resistance as the adapter O ring is forced into the detector exhaust vent Twist and push the adapter during insertion to ensure a good seal For the FPD remove the vent tube assembly and use a 1 4 in tube adapter between the detector exhaust and the flowmeter tubing WARNING Hydrogen H2 is ...

Page 85: ...Troubleshooting Tasks 8 Troubleshooting 85 5 Connect the flowmeter to the flowmeter adapter to measure flow rates Measuring NPD column flow 1 Gather the following NPD flowmeter adapter tool G1534 60640 ...

Page 86: ...oncern 2 Set the bead voltage to 0 0 V 3 Cool the NPD to 100 C 4 Remove the bead and store it carefully until re installation 5 Insert the NPD flowmeter adapter tool into the NPD collector 6 Attach the flow measuring insert to the NPD flowmeter adapter tool 7 Place the flowmeter tubing over the flow measuring insert to begin measuring flows ...

Page 87: ...ate and use a 1 8 in tube adapter as shown below to convert the 1 8 in threaded fitting into a 1 8 in tube This prevents the rubber flowmeter tubing from leaking around the threads which will result in leakage and thus an incorrect flow reading WARNING Hydrogen H2 is flammable and is an explosion hazard when mixed with air in an enclosed space for example a flow meter Purge flowmeters with inert g...

Page 88: ...88 Troubleshooting 8 Troubleshooting Tasks ...

Page 89: ...D exhaust vent A separate adapter is supplied for the FID Insert the adapter into the detector exhaust vent as far as possible You will feel resistance as the adapter O ring is forced into the detector exhaust vent Twist and push the adapter during insertion to ensure a good seal For FPD remove the vent tube assembly and use a 1 4 inch tube adapter between the detector exhaust and the flowmeter tu...

Page 90: ...90 Troubleshooting 8 Troubleshooting Tasks 7 Connect the flowmeter to the flowmeter adapter and measure flows Measuring NPD flows 1 Gather the following NPD flowmeter adapter tool G1534 60640 ...

Page 91: ...oncern 2 Set the bead voltage to 0 0 V 3 Cool the NPD to 100 C 4 Remove the bead and store it carefully until re installation 5 Insert the NPD flowmeter adapter tool into the NPD collector 6 Attach the flow measuring insert to the NPD flowmeter adapter tool 7 Place the flowmeter tubing over the flow measuring insert to begin measuring flows ...

Page 92: ...92 Troubleshooting 8 Troubleshooting Tasks To Perform the GC Self Test 1 Turn the GC off 2 Wait 1 min then turn the GC back on If the main GC status screen appears the GC has passed the self test ...

Page 93: ... 1 Press Config 2 Scroll to Front detector or Back detector wherever the detector is installed and press Enter 3 Scroll to Lit offset With the Lit offset line highlighted enter the new parameter for the detector and press Enter 4 Lit offset should be 2 0 pA or lower than the normal FID output when lit ...

Page 94: ...FID Flame Is Lit To verify that the FID flame is lit hold a mirror or other reflective surface over the collector exhaust Steady condensation indicates that the flame is lit Typically the FID output will be between 5 0 and 20 0 pA when lit and 2 0 pA when not lit ...

Page 95: ...1 Remove the detector top cover 2 Turn the FID flame On 3 Observe the ignitor plug though the FID chimney The small hole should glow during ignition sequence WARNING Keep body parts at a safe distance from the FID chimney while performing this task If using hydrogen the FID flame will not be visible ...

Page 96: ...to 300 C 2 Turn off the FID flame 3 Verify that the FID electrometer is on 4 Press Front Detector or Back Detector then scroll to Output 5 Verify that the output is stable and 1 0 pA If the output is unstable or 1 0 pA turn off the GC and check for proper assembly of the upper FID parts and for contamination If the contamination is confined to the detector bakeout the FID 6 Turn on the flame ...

Page 97: ...oven temperature to 35 C 3 Press Front Detector or Back Detector then scroll to Output 4 When the flame is lit and the GC is ready verify that the output is stable and 20 pA this may take some time 5 If the output is not stable or 20 pA the system or gas may be contaminated If this contamination is isolated to the detector bakeout the FID ...

Page 98: ...d the Bead Voltage to 0 00 V Leave the NPD at operating temperature Leave flows on or off 3 Press Front Detector or Back Detector then scroll to Output 4 Verify that the output leakage current is stable and 1 0 pA 5 The output should slowly drop toward 0 0 pA and should stabilize in the tenths of a picoamp Current 2 0pA indicates a problem ...

Page 99: ...that the bead is ignited look through the vent hole on the detector lid to see if the bead is glowing orange The NPD output is selected by the operator as part of the adjust offset process and generally is between 5 0 and 50 0 pA WARNING Hot exhaust Detector exhaust is hot and can cause burns ...

Page 100: ...asks To Verify That the FPD Flame Is Lit To verify that the FPD flame is lit 1 Remove the rubber drip tube from the detector vent 2 Hold a mirror or shiny surface near the aluminum exhaust tube Steady condensation means that the flame is lit ...

Page 101: ...To adjust the FPD Lit offset 1 Press Config 2 Scroll to Front detector or Back detector wherever the detector is installed and press Enter 3 Scroll to Lit offset With the Lit offset line highlighted enter the new parameter for the FPD typical value is 2 0 pA and press Enter ...

Page 102: ...102 Troubleshooting 8 Troubleshooting Tasks ...

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