TELEDYNE API T703U - Page 12

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Verify Subsystem Calibration .............................................................................................................. 163
8.4.1.
AC Main Power ................................................................................................................................... 163 8.4.2.
DC Power Supply ................................................................................................................................ 163 8.4.3.
I
2
C Bus ................................................................................................................................................ 165 8.4.4.
Touchscreen Interface ......................................................................................................................... 165 8.4.5.
LCD Display Module ............................................................................................................................ 165 8.4.6.
Relay PCA ........................................................................................................................................... 165 8.4.7.
Photometer O
3
Generator Pressure /Flow Sensor Assembly ............................................................. 166 8.4.8.
Motherboard ........................................................................................................................................ 168 8.4.9.
A/D Functions............................................................................................................................... 168 8.4.9.1.
Test Channel / Analog Outputs Voltage ...................................................................................... 169 8.4.9.2.
Status Outputs ............................................................................................................................. 170 8.4.9.3.
Control Inputs ............................................................................................................................... 171 8.4.9.4.
Control Outputs ............................................................................................................................ 171 8.4.9.5.
CPU ................................................................................................................................................... 172
8.4.10.
RS-232 Communications .................................................................................................................. 172 8.4.11.
General RS-232 Troubleshooting .............................................................................................. 172 8.4.11.1.
Troubleshooting Calibrator/Modem or Terminal Operation ....................................................... 173 8.4.11.2.
Temperature Problems ...................................................................................................................... 173 8.4.12.
Box / Chassis Temperature ....................................................................................................... 173 8.4.12.1.
Photometer Sample Chamber Temperature .............................................................................. 173 8.4.12.2.
UV Lamp Temperature .............................................................................................................. 174 8.4.12.3.
Ozone Generator Temperature.................................................................................................. 174 8.4.12.4.
8.5. Troubleshooting the O
3
Photometer .......................................................................................................... 174
Dynamic Problems with the O
3
Photometer ........................................................................................ 174 8.5.1.
Noisy or Unstable O
3
Readings at Zero ....................................................................................... 175 8.5.1.1.
Noisy, Unstable, or Non-Linear Span O
3
Readings ..................................................................... 175 8.5.1.2.
Slow Response to Changes in Concentration ............................................................................. 175 8.5.1.3.
The Analog Output Signal Level Does Not Agree With Front Panel Readings ........................... 175
8.5.1.4.
Cannot Zero ................................................................................................................................. 176 8.5.1.5.
Cannot Span ................................................................................................................................ 176 8.5.1.6.
Checking Measure / Reference Valve ................................................................................................. 176 8.5.2.
8.6. Trouble Shooting the O
3
Generator ........................................................................................................... 176
Troubleshooting the O
3
Generator in the T703 ................................................................................... 177 8.6.1.
Troubleshooting the O
3
Generator in the T703U ................................................................................ 177 8.6.2.
8.7. Repair Procedures ..................................................................................................................................... 178
Repairing Sample Flow Control Assembly .......................................................................................... 178 8.7.1.
Disk-On-Module Replacement Procedure .......................................................................................... 178 8.7.2.
8.8. FAQ‟s ......................................................................................................................................................... 180
8.9. Technical Assistance ................................................................................................................................. 180
9. PRINCIPLES OF OPERATION ......................................................................................... 181
9.1. Pneumatic Operation ................................................................................................................................. 181
Gas Flow Control ................................................................................................................................. 181 9.1.1.
Photometer Critical Flow Orifice .................................................................................................. 182 9.1.1.1.
Internal Gas Pressure Sensors ........................................................................................................... 182 9.1.2.
9.2. Electronic Operation .................................................................................................................................. 183
Overview .............................................................................................................................................. 183 9.2.1.
Central Processing Unit (CPU)............................................................................................................ 184 9.2.2.
Disk On Module (DOM) ................................................................................................................ 185 9.2.2.1.
Flash Chip .................................................................................................................................... 185 9.2.2.2.
Relay PCA ........................................................................................................................................... 185 9.2.3.
Valve Control ................................................................................................................................ 186 9.2.3.1.
Heater Control .............................................................................................................................. 187 9.2.3.2.
Relay PCA Status LEDs and Watch Dog Circuitry ...................................................................... 187 9.2.3.3.
Relay PCA Watchdog Indicator (D1) ........................................................................................... 188 9.2.3.4.
Motherboard ........................................................................................................................................ 189 9.2.4.
07223D DCN7107