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pH/chlorine regulator AUTODOS 5000 - 2005-01-21
Eng_Autodos5000.doc ver 3.2 - page 11
2.4. Description of on/off Dosing Control
2.4.1. Acid/Alkali Dosing (on/off) by pH Control
The drawing below illustrates both acid and alkali dosing. AUTODOS 5000 uses acid or alkali dosing (selected in
setup-mode).
set value
alkali dosing
monitored value
acid dosing
Acid dosing:
If the pH exceeds the acid set value then acid dosing begins and continues until the pH is returned to the acid set
value.
Alkali dosing:
If the pH falls below the alkali set value then alkali dosing will commence and continue until the pH exceeds the
alkali set value.
2.4.2. Chlorine Dosing (on/off) by Chlorine Monitoring
set value
chlorine dosing off
monitored value
chlorine dosing on
As long as the monitored value exceeds the set value then chlorine dosing is inactive. If the chlorine level falls below
the set value then chlorine dosing commences and will continue until the chlorine level equals or exceeds the
monitored value.
The example above shows the action for regulation of free chlorine, where chemicals are added to get higher free
chlorine value. Regulation of combined chlorine works in the opposite manner, dosing is used for lowering the
combined chlorined value.