4
AW T4 20 |
U N I V ER S A L 4 - W I R E , D UA L- I N P U T T R A N SM I T T ER | O I/AW T4 2 0 - EN 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
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-acting control . . . . . . . . . . . . . . . . . . . . . . 105
Direct-acting control. . . . . . . . . . . . . . . . . . . . . . . . 105
Dual-acting control . . . . . . . . . . . . . . . . . . . . . . . . .106
Manual Reset (proportional band offset) . . . . . . . . . 106
Output type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Pulse frequency output . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Appendix E Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Sensor module assemblies . . . . . . . . . . . . . . . . . . . . . . . 108
EZLink module assemblies . . . . . . . . . . . . . . . . . . . . . . . 108
AWT420 EZLink PCB upgrade/spares kit . . . . .108
Communications module assemblies . . . . . . . . . . . . . 108
Mounting kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Weathershield kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Gland packs/EZLink connectors . . . . . . . . . . . . . . . . . . 109