08593A DCN7927 vii
6.5. Analog Input (AIN) Calibration ........................................................................................................ 87
MAINTENANCE AND SERVICE .............................................................................. 89
7.1. Maintenance Schedule ................................................................................................................... 89
7.2. Operational Health Checks............................................................................................................. 93
7.3. Software/Firmware Updates ........................................................................................................... 93
Remote Updates ...................................................................................................................... 93
Manual Reload/Update Procedures ......................................................................................... 94
7.4. Performing Leak Checks ................................................................................................................ 95
7.5. Cleaning or Replacing the Absorption Tube ................................................................................... 97
7.6. Assessing Usage of and Replacing Desiccant (Silica Gel) ............................................................ 98
7.7. Adjusting the Photometer UV Source Lamp ................................................................................. 100
7.8. Replacing the Photometer UV Source Lamp ............................................................................... 101
7.9. Adjusting or Replacing the Ozone Generator UV Lamp .............................................................. 102
GENERAL TROUBLESHOOTING & SERVICE ..................................................... 103
8.1. General Troubleshooting .............................................................................................................. 103
Fault Diagnosis with Messages in the Alerts Page ................................................................ 104
Fault Diagnosis With Dashboard Functions ........................................................................... 105
Using the Diagnostic Analog Inputs Function ........................................................................ 106
8.2. Using the Signal Outputs for Diagnostics ..................................................................................... 107
8.3. Using the Internal Electronic Status LEDs ................................................................................... 108
CPU Status Indicator .............................................................................................................. 108
Power Distribution Board Status LEDs .................................................................................. 108
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2
C Bus Watchdog Status LEDs ...................................................................................... 109
Troubleshooting with Power Distribution Board Status LEDs ......................................... 109
8.4. Subsystem Checkout .................................................................................................................... 111
Verify Subsystem Calibration ................................................................................................. 111
AC Main Power ...................................................................................................................... 111
DC Power Supply ................................................................................................................... 111
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2
C Bus ................................................................................................................................... 113
Touchscreen Interface ............................................................................................................ 113
Power Distribution Board ........................................................................................................ 114
Photometer O
3
Generator Pressure /Flow Sensor Assembly ................................................ 114
Motherboard ........................................................................................................................... 116
A/D Functions .................................................................................................................. 116
Test Channel / Analog Outputs Voltage ......................................................................... 116
Status Outputs (Digital Output Pins 1 – 8) ...................................................................... 117
Digital Control Inputs ....................................................................................................... 117
Control Outputs (Digital Output Pins 1 – 12) .................................................................. 118
CPU ........................................................................................................................................ 119
RS-232 Communications ..................................................................................................... 119
General RS-232 Troubleshooting ................................................................................. 119
Temperature Problems ......................................................................................................... 119
Box / Chassis Temperature .......................................................................................... 119
Photometer Sample Chamber Temperature ................................................................. 119
UV Lamp Temperature ................................................................................................. 120
Ozone Generator Temperature ..................................................................................... 120
8.5. Troubleshooting the O
3
Photometer ............................................................................................. 121
Dynamic Problems with the O
3
Photometer ........................................................................... 121
Noisy or Unstable O
3
Readings at Zero .......................................................................... 121
Noisy, Unstable, or Non-Linear Span O
3
Readings ........................................................ 121
Slow Response to Changes in Concentration ................................................................ 121
The Analog Output Signal Level Does Not Agree With Input / Control Panel Readings 122
Cannot Zero .................................................................................................................... 122
Cannot Span ................................................................................................................... 122
Checking Measure / Reference Valve .................................................................................... 122
8.6. Troubleshooting the O
3
Generator ............................................................................................... 123