Teledyne GFC-7000E - Trace CO2 Analyzer User Manual
Page 6
Model GFC7000E Instruction Manual GFC7000E
Documentation
04584 Rev A1
v
10.3. Electronic Operation........................................................................................................... 161
10.3.1. Overview ................................................................................................................... 161
10.3.2. CPU........................................................................................................................... 163
10.3.3. Optical Bench & GFC Wheel........................................................................................... 163
10.3.3.1. Sample Gas and GFC Temperature Control ............................................................... 163
10.3.3.2. IR Source ............................................................................................................ 164
10.3.3.3. GFC Wheel ........................................................................................................... 164
10.3.3.4. IR Photo-Detector ................................................................................................. 165
10.3.4. Synchronous Demodulator (Sync/Demod) Assembly......................................................... 165
10.3.4.1. Overview ............................................................................................................. 165
10.3.4.2. Signal Synchronization and Demodulation ................................................................ 166
10.3.4.3. Phase Lock Warning .............................................................................................. 167
10.3.4.4. Sync/Demod Status LED’s ...................................................................................... 167
10.3.4.5. Photo-Detector Temperature Control........................................................................ 168
10.3.4.6. Dark Calibration Switch.......................................................................................... 168
10.3.4.7. Electric Test Switch ............................................................................................... 168
10.3.5. Relay Board................................................................................................................ 168
10.3.5.1. Status LED’s......................................................................................................... 169
10.3.5.2.
I
2
C
Watch Dog Circuitry ........................................................................................ 170
10.3.6. Mother Board.............................................................................................................. 170
10.3.6.1. A to D Conversion ................................................................................................. 170
10.3.6.2. Sensor Inputs....................................................................................................... 171
10.3.6.3. Thermistor Interface.............................................................................................. 171
10.3.6.4. Analog Outputs..................................................................................................... 172
10.3.6.5. Internal Digital I/O................................................................................................ 172
10.3.6.6. External Digital I/O ............................................................................................... 173
10.3.7. I
2
C Data Bus............................................................................................................... 173
10.3.8. Power Supply/ Circuit Breaker ....................................................................................... 173
10.4. Interface .......................................................................................................................... 174
10.4.1. Front Panel Interface ................................................................................................... 175
10.4.1.1. Analyzer Status LED’s............................................................................................ 175
10.4.1.2. Keyboard ............................................................................................................. 176
10.4.1.3. Display ................................................................................................................ 176
10.4.1.4. Keyboard/Display Interface Electronics..................................................................... 177
10.5. Software Operation ............................................................................................................ 178
10.5.1. Adaptive Filter ............................................................................................................ 179
10.5.2. Calibration - Slope and Offset........................................................................................ 179
10.5.3. Measurement Algorithm ............................................................................................... 180
10.5.4. Temperature and Pressure Compensation ....................................................................... 180
10.5.5. Internal Data Acquisition System (iDAS) ......................................................................... 180
11. TROUBLESHOOTING & REPAIR PROCEDURES ........................................................................ 183
11.1. General Troubleshooting Hints ............................................................................................. 183
11.1.1. Interpreting WARNING Messages ................................................................................... 184
11.1.2. Fault Diagnosis with TEST Functions............................................................................... 186
11.1.3. Using the Diagnostic Signal I/O Function......................................................................... 188
11.1.4. Internal Electronic Status LED’s ..................................................................................... 189
11.1.4.1. CPU Status Indicator ............................................................................................. 189
11.1.4.2. Sync Demodulator Status LED’s .............................................................................. 190
11.1.4.3. Relay Board Status LED’s ....................................................................................... 191
11.1.5. Gas Flow Problems ...................................................................................................... 192
11.1.6. Typical Sample Gas Flow Problems................................................................................. 193
11.1.6.1. Flow is Zero ......................................................................................................... 193
11.1.6.2. Low Flow ............................................................................................................. 193
11.1.6.3. High Flow ............................................................................................................ 194
11.1.6.4. Displayed Flow = “XXXX” ....................................................................................... 194
11.1.6.5. Actual Flow Does Not Match Displayed Flow .............................................................. 194
11.1.6.6. Sample Pump ....................................................................................................... 194
11.1.7. Poor or Stopped Flow of Purge Gas ................................................................................ 194
11.2. Calibration Problems .......................................................................................................... 195
11.2.1. Miss-Calibrated ........................................................................................................... 195