Automatic Coagulation Control System for Water Treatment

Discover our coagulant dose control system

Automatic Coagulation Control from PMA uses the on-line spectroscopy combines with turbidity to predict the ideal coagulant dose in real time based on current raw water quality.


Achieve your treatment aims whether that be reduced turbidity breakthrough or enhanced organics removal.

Compass Coagulation Control System

Compass is a cutting-edge advanced automatic coagulation control system for water treatment, suitable for use with any coagulant.


Used in feed forward mode, it can adjust coagulant dose in the face of rapid raw water quality changes.


In feedback mode, it can ensure maximum organics removal and even output online disinfection by-products parameters such as THM formation potential and HAA5 formation potential.

The key benefits

Our award winning coagulation control system is especially effective on flashy water sources and optimises coagulant dose to achieve your drinking water treatment aims.


Instant response to raw water changes.


Unaffected independent process control.


Eradicates under-dosing and increases plant performance.


Eradicates overdosing and decreases operating costs.

Benefits of

using compass

Conventional Mode

  • Max Turbidity removal-all conditions
  • Very low metal residuals
  • Max removal of coagulable organics
  • Longer filter run times
  • Reduced chlorine demand

Enhanced Mode

  • Reduced sludge load
  • Reduced risk of DBP formation
  • Reduced chemical costs
  • More stable chlorine residuals

Truly advanced

Compass will provide the optimum coagulant dose based on the raw water conditions and provide a mg/l output predicted dose to SCADA.

Automatic coagulation control solution for drinking water from PMA Ltd.


The Compass feed forward control system is designed for turbidity removal in drinking water treatment. It provides the best system to meet filter turbidity targets (e.g. <0.1NTU) at the lowest coagulant dose possible.

Compass EOR

The Compass enhanced organics removal (EOR) feedback system is aimed for users seeking to minimise dissolved organics in the filtered water. It delivers the optimum dose to meet filter turbidity objectives and maximise dissolved organics removal.

Want to know more?

Check out our related articles

Find out more about how a Compass automatic coagulation control system works

How does UV spectroscopy allow Compass to determine NOM character in real time and why does this make it a more effective coagulation control system than alternative approaches?

How does the enhanced organics removal (EOR) version differ from the feed forward version?

Compass EOR operates a feedback UV254 sensor post primary treatment to trim the feed forward dose. Find out more about how this works here.

Automatic Coagulation Control

Compass EOR coagulation control setup

A Compass EOR system in action.


Utilising a UV-Vis spectrophotometer and a turbidity sensor in the trough, the signals are fed back to the Compass EOR PC which calculates the ideal coagulant dose for the raw water in real time.


In addition, a separate UV254 sensor is installed on the post primary treatment sample. The result from this is fed back to the EOR PC which then trims the feed forward result based on the organics present in the treated sample.

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