4
Agilent 7820 GC Service
About the detector signal boards ............. 40
Accessing detector signal boards ............. 41
Replacing detector signal boards ............. 41
Flame Ionization Detector (FID) .............. 44
Selecting an FID jet ...................... 44
Replacing the FID interconnect assembly or
spring .................................... 46
Replacing the heater ...................... 48
Replacing the FID signal board ............ 53
Replacing the electrometer ................ 54
Replacing the glow plug (ignitor) ......... 55
Replacing the entire FID .................. 57
Ultrasonic cleaning the FID ............... 62
Nitrogen Phosphorus Detector (NPD) ........... 65
Selecting an NPD jet ...................... 65
Removing the NPD electrometer ............. 66
Replacing the entire NPD .................. 67
Replacing an NPD signal board ............ 70
Replacing the NPD heater .................. 72
Replacing the NPD electrometer ............ 74
Cleaning the NPD jet and collector ........ 76
Cleaning the NPD .......................... 78
Thermal Conductivity Detector (TCD) .......... 81
Replacing the TCD detector cell ........... 81
Replacing the TCD switching valve ......... 83
Micro-cell Electron Capture Detector (uECD) . 85
Replacing the uECD heater/sensor assembly . 85
Replacing the uECD makeup gas adapter ..... 86
Frequency test ............................ 87
Leak test ................................. 89
Performing a radioactivity leak test (wipe test)
........................................... 89
Flame Photometric Detector (FPD) ............. 91
Preparing for maintenance ................. 91
Disassembling the FPD ..................... 91
Rebuilding the FPD optics assembly ....... 101