Model 6200E Instruction Manual
6 M6200E Rev: A1
8.4.2. Precision Check............................................................................................................. 185
8.5. Dynamic Multipoint Span Calibration ...................................................................................... 185
8.6. Special Calibration Requirements for Independent Range or Auto Range...................................... 186
8.7. References ......................................................................................................................... 187
9. INSTRUMENT MAINTENANCE ....................................................................................................189
9.1. Maintenance Schedule.......................................................................................................... 189
9.2. Predictive Diagnostics .......................................................................................................... 192
9.3. Maintenance Procedures....................................................................................................... 193
9.3.1. Changing the Sample Particulate Filter ............................................................................. 193
9.3.2. Changing the IZS Permeation Tube.................................................................................. 194
9.3.3. Maintaining the SO
2
Scrubber ......................................................................................... 194
9.3.3.1. Predicting When the SO
2
Scrubber Should Be Replaced. ............................................... 194
9.3.3.2. Checking the Function of the SO
2
Scrubber................................................................. 195
9.3.3.3. Changing the SO
2
Scrubber Material .......................................................................... 195
9.3.4. Changing the External Zero Air Scrubber .......................................................................... 196
9.3.5. Maintaining the H
2
S Æ SO
2
Converter .............................................................................. 197
9.3.5.1. Predicting When the Converter Catalyst Should Be Replaced. ........................................ 197
9.3.5.2. Checking the Efficiency of the H
2
S Æ SO
2
Converter..................................................... 197
9.3.5.3. Changing the H
2
S Æ SO
2
Converter Catalyst Material ................................................... 198
9.3.6. Cleaning the Sample chamber......................................................................................... 199
9.3.7. Cleaning or Changing Critical Flow Orifices........................................................................ 200
9.3.8. Checking for Light Leaks ................................................................................................ 201
10. THEORY OF OPERATION..........................................................................................................203
10.1. Measurement Principle ....................................................................................................... 203
10.1.1. H2S Conversion .......................................................................................................... 203
10.1.2. SO
2
Ultraviolet Fluorescence ......................................................................................... 204
10.2. The UV Light Path .............................................................................................................. 206
10.2.1. UV Source Lamp ......................................................................................................... 207
10.2.2. The Reference Detector................................................................................................ 208
10.2.3. The PMT..................................................................................................................... 208
10.2.4. Optical Filters ............................................................................................................. 208
10.2.4.1. UV Source Optical Filter ......................................................................................... 208
10.2.4.2. PMT Optical Filter.................................................................................................. 209
10.2.5. Optical Lenses ............................................................................................................ 210
10.2.6. Measurement Interferences .......................................................................................... 210
10.2.6.1. Direct Interference................................................................................................ 211
10.2.6.2. UV Absorption by Ozone ........................................................................................ 211
10.2.6.3. Dilution ............................................................................................................... 211
10.2.6.4. Third Body Quenching............................................................................................ 211
10.2.6.5. Light Pollution ...................................................................................................... 212
10.3. Pneumatic Operation.......................................................................................................... 212
10.3.1. sample gas Flow.......................................................................................................... 213
10.3.2. Multigas Measurement & H
2
S Æ SO
2
Switching Valve. ....................................................... 213
10.3.3. Flow Rate Control ........................................................................................................ 214
10.3.3.1. Critical Flow Orifice ............................................................................................... 214
10.3.4. Sample Particulate Filter............................................................................................... 215
10.3.5. Hydrocarbon Scrubber (Kicker) ..................................................................................... 215
10.3.6. SO
2
Scrubber.............................................................................................................. 216
10.3.7. Pneumatic Sensors ...................................................................................................... 216
10.3.7.1. Sample Pressure Sensor ........................................................................................ 216
10.3.7.2. Sample Flow Sensor .............................................................................................. 217
10.4. Electronic Operation........................................................................................................... 218
10.4.1. CPU........................................................................................................................... 219
10.4.1.1. Disk On Chip ........................................................................................................ 220
10.4.1.2. Flash Chip............................................................................................................ 220
10.4.2. Sensor Module & Sample chamber ................................................................................. 221
10.4.3. Sample Chamber Heating Circuit ................................................................................... 221
10.4.4. Photo Multiplier Tube (PMT) .......................................................................................... 222
10.4.5. PMT Cooling System. ................................................................................................... 223
10.4.5.1. Thermoelectric Cooler (TEC) ................................................................................... 223
10.4.5.2. TEC Control Board................................................................................................. 224
10.4.6. PMT Preamplifier ......................................................................................................... 224