ABB AWT420 Operating Instruction page 4

4 AW T4 2 0 | U N I V E R S A L 4 - W I R E , D U A L- I N P U T T R A N S M I T T E R | O I/A W T4 2 0 - E N R E V. 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
total dissolved solids (TDS) measurement . . . . . . . . 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
Dual-acting (Acid and Base) control . . . . . . . . . . 104
Operator menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Control action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Reverse-acting control . . . . . . . . . . . . . . . . . . . . . . 105
Direct-acting control. . . . . . . . . . . . . . . . . . . . . . . . 105
Dual-acting control . . . . . . . . . . . . . . . . . . . . . . . . . 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