Teledyne GFC-7000E - Trace CO2 Analyzer - Manual (Page 7)

Model GFC7000E Instruction Manual GFC7000E Documentation
04584 Rev A1 vi
11.2.2. Non-Repeatable Zero and Span ..................................................................................... 195
11.2.3. Inability to Span – No SPAN Key.................................................................................... 196
11.2.4. Inability to Zero – No ZERO Key .................................................................................... 196
11.3. Other Performance Problems ............................................................................................... 196
11.3.1. Temperature Problems ................................................................................................. 197
11.3.1.1. Box or Sample Temperature ................................................................................... 197
11.3.1.2. Bench Temperature............................................................................................... 197
11.3.1.3. GFC Wheel Temperature ........................................................................................ 198
11.3.1.4. IR Photo-Detector TEC Temperature ........................................................................ 198
11.3.2. Excessive Noise........................................................................................................... 198
11.4. Subsystem Checkout.......................................................................................................... 199
11.4.1. AC Mains Configuration ................................................................................................ 199
11.4.2. DC Power Supply......................................................................................................... 200
11.4.3. I 2 C Bus ...................................................................................................................... 200
11.4.4. Keyboard/Display Interface........................................................................................... 201
11.4.5. Relay Board................................................................................................................ 201
11.4.6. Sensor Assembly......................................................................................................... 202
11.4.6.1. Sync/Demodulator Assembly .................................................................................. 202
11.4.6.2. Opto Pickup Assembly ........................................................................................... 202
11.4.6.3. GFC Wheel Drive................................................................................................... 203
11.4.6.4. IR Source ............................................................................................................ 203
11.4.6.5. Pressure/Flow Sensor Assembly .............................................................................. 203
11.4.7. Motherboard............................................................................................................... 204
11.4.7.1. A/D Functions....................................................................................................... 204
11.4.7.2. Analog Outputs: Voltage ........................................................................................ 204
11.4.7.3. Analog Outputs: Current Loop................................................................................. 204
11.4.7.4. Status Outputs ..................................................................................................... 205
11.4.7.5. Control Inputs – Remote Zero, Span........................................................................ 205
11.4.8. CPU........................................................................................................................... 206
11.4.9. RS-232 Communications .............................................................................................. 206
11.4.9.1. General RS-232 Troubleshooting ............................................................................. 206
11.4.9.2. Troubleshooting Analyzer/Modem or Terminal Operation............................................. 207
11.5. Repair Procedures.............................................................................................................. 207
11.5.1. Repairing Sample Flow Control Assembly ........................................................................ 207
11.5.2. Removing/Replacing the GFC Wheel ............................................................................... 209
11.5.3. Disk-On-Chip Replacement Procedure............................................................................. 210
12. A PRIMER ON ELECTRO-STATIC DISCHARGE.......................................................................... 213
12.1. How Static Charges are Created........................................................................................... 213
12.2. How Electro-Static Charges Cause Damage ........................................................................... 214
12.3. Common Myths About ESD Damage ..................................................................................... 215
12.4. Basic Principles of Static Control .......................................................................................... 216
12.4.1. General Rules ............................................................................................................. 216
12.4.2. Basic anti-ESD Procedures for Analyzer Repair and Maintenance ........................................ 218
12.4.2.1. Working at the Instrument Rack.............................................................................. 218
12.4.2.2. Working at a Anti-ESD Work Bench.......................................................................... 218
12.4.2.3. Transferring Components from Rack To Bench and Back ............................................. 219
12.4.2.4. Opening Shipments from and Packing Components for Return to Teledyne Instruments
Customer Service. .............................................................................................................. 219