Teledyne T400, User Manual, Page: 13 / 177

083730400A DCN8130 Teledyne API – Model T400 O
3
Analyzer xi
5.7.13 Troubleshooting the Photometer ....................................................................................................131
5.7.13.1 Checking the Measure/Reference Valve .........................................................................131
5.7.13.2 Checking the Photometer UV Lamp Power Supply ........................................................131
5.7.14 Troubleshooting the IZS Option’s O
3
Generator ............................................................................132
5.7.15 Service Procedures ........................................................................................................................132
5.7.15.1 Repairing Sample Flow Control Assembly ......................................................................132
5.7.15.2 Replacing the Standard Reference O3 Scrubber ............................................................133
5.7.15.3 Replacing the IZS O
3
Scrubber .......................................................................................133
5.7.15.4 Replacing the Metal Wool Scrubber Option ....................................................................134
5.7.15.5 Replacing the UV Lamp Driver Board .............................................................................134
5.7.15.6 Disk-On-Module Replacement ........................................................................................136
5.8 Frequently Asked Questions .....................................................................................................................137
5.9 Technical Assistance .................................................................................................................................138
6. Theory of Operation ................................................................................................................ 139
6.1 Measurement Method ................................................................................................................................139
6.1.1 Calculating O
3
Concentration .........................................................................................................140
6.1.2 The Photometer UV Absorption Path .............................................................................................141
6.1.3 The Reference / Measurement Cycle ............................................................................................142
6.1.4 Interferent Rejection .......................................................................................................................143
6.1.4.1 Aromatic Hydrocarbons ...................................................................................................143
6.1.4.2 Mercury Vapor .................................................................................................................143
6.2 Pneumatic Operation .................................................................................................................................143
6.2.1 Sample Gas Air Flow .....................................................................................................................144
6.2.2 Flow Rate Control ..........................................................................................................................144
6.2.3 Particulate Filter .............................................................................................................................145
6.2.4 Pneumatic Sensors ........................................................................................................................146
6.2.4.1 Sample Pressure Sensor.................................................................................................146
6.2.4.2 Sample Flow Sensor .......................................................................................................146
6.3 Electronic Operation ..................................................................................................................................146
6.3.1 CPU ................................................................................................................................................148
6.3.1.1 Disk-On-Module (DOM) ...................................................................................................148
6.3.1.2 Flash Chip .......................................................................................................................148
6.3.2 Motherboard ...................................................................................................................................149
6.3.2.1 A to D Conversion ...........................................................................................................149
6.3.2.2 Sensor Inputs ..................................................................................................................149
6.3.2.3 Thermistor Interface ........................................................................................................149
6.3.2.4 Analog Outputs ................................................................................................................150
6.3.2.5 External Digital I/O ...........................................................................................................150
6.3.2.6 Power up Circuit ..............................................................................................................150
6.3.2.7 I
2
C Data Bus ....................................................................................................................151
6.3.3 Relay Board ...................................................................................................................................151
6.3.3.1 Status LEDs .....................................................................................................................152
6.3.3.2 I
2
C Watch Dog Circuitry ...................................................................................................153
6.3.3.3 Heater Control .................................................................................................................153
6.3.3.4 Valve Control ...................................................................................................................154
6.3.3.5 Thermocouple Inputs and Configuration Jumper (JP5) ..................................................155
6.3.4 Power Supply/ Circuit Breaker .......................................................................................................156
6.3.5 AC Power Configuration .................................................................................................................157
6.3.5.1 AC Configuration – Internal Pump (JP7) .........................................................................158
6.3.5.2 AC Configuration – Heaters for Option Packages (JP6) .................................................158
6.3.6 Photometer Layout and Operation .................................................................................................159
6.3.7 Front Panel Touchscreen/Display Interface ...................................................................................160
6.1.1.1 LVDS Transmitter Board .................................................................................................161
6.1.1.2 Front Panel Touchscreen/Display Interface PCA ............................................................161