ABB AWT420 - Page 4

4 AWT420 | UNIVERSAL 4-WIRE, DUAL-INPUT TRANSMITTER | OI/AWT420-EN REV. B
Contents
Appendix A pH solution coefficient ............ 97
Appendix B 2-electrode
conductivity calculations ....................... 98
Automatic temperature compensation ............ 98
Calculation of temperature coefficient.......100
Relationship between conductivity and
 ........100
Appendix C Dual 2-electrode
conductivity calculations .......................101
Inferred pH derived from differential conductivity .101
Monitoring on steam-raising plant...........101
Monitoring on AVT systems ...................... 102
Monitoring on AVT systems with impurities ....... 102
Monitoring on solid alkaline treated systems ...... 103
Appendix D PID control....................... 104
Operator pages ................................. 104
Reverse or direct-acting control .............104
..........104
Operator menus ................................. 105
Control action ................................... 105
Reverse-acting control ......................105
........................105
 .........................106
Manual Reset (proportional band offset) .........106
Output type ..................................... 107
Analog output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Time proportioning output..................107
Pulse frequency output .......................... 107
Appendix E Spares ........................... 108
Sensor module assemblies .......................108
AWT420 pH PCB upgrade/spares kit .........108
AWT420 2-electrode conductivity
PCB upgrade/spares kit .....................108
AWT420 4-electrode conductivity
PCB upgrade/spares kit .....................108
EZLink module assemblies .......................108
AWT420 EZLink PCB upgrade/spares kit .....108
Communications module assemblies .............108
AWT420 HART PCB upgrade/spares kit.......108
AWT420 Profibus PCB upgrade/spares kit....108
AWT420 Modbus PCB upgrade/spares kit ....108
AWT420 Ethernet PCB upgrade/spares kit....108
AWT420 analog output PCB upgrade/
spares kit ..................................108
Mounting kits ................................... 109
Panel-mount kit ............................109
Pipe-mount kit .............................109
Wall-mount kit..............................109
Weathershield kits .............................. 109
Weathershield kit ...........................109
Weathershield and pipe-mount kit ...........109
Gland packs/EZLink connectors .................. 109
Gland packs ................................109
EZLink connector assembly .................109