Zetasizer WT


Malvern Panalytical

Malvern Panalytical

Zetasizer WT On-line zeta potential analyzer for water treatment processes The Zetasizer WT is a fully automated system that delivers lab quality on-line zeta potential measurements. This enables real-time monitoring of flocculation process performance and efficient charge neutralization. On-line charge measurements you can trust are finally here!

Key Differences

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The Zetasizer WT combines Malvern Panalytical’s industry leading Electrophoretic Light Scattering technology with two decades of expertise with in-process measurements to produce a dedicated on-line zeta potential analyzer for water treatment plants.

No more guess work – accurate and reliable results in [mV] provide a clear range for dosing control.

Respond to changes in raw water before they cause filtration problems!

Reduce chemical use to optimum for forming a stable floc. Overdose no more!

  • Completely automated zeta potential analysis with results in minutes.

  • Results sent to SCADA via OPC, Modbus or 4-20mA

  • Minimal maintenance

  • Easy measurement of grab samples on the same system.

  • HMI for local control and setup

  • On board computer for autonomous operation

  • Sample flow and temperature sensing

How it works

The Zetasizer WT connects to a sample stream coming from the plant after coagulants have been added and mixed into the water. The system uses a pump to flow a sample through the analyzer`s flow cell where zeta potential measurements are made. Sample is then pumped into waste or returned back into the process and replaced with a fresh sample in a continuous, automatic cycle.


Automation and analysis is controlled by an on-board industrial computer running Malvern Panalytical Link II software. 

Measurement results are displayed on a local HMI screen as well as exported into plant SCADA via OPC, Modbus TCP/IP or wired 4-20mA connections.

Results are used by treatment plant operators or a plant control system to adjust coagulant dose required to keep zeta potential in a pre-determined range – typically between zero and a slight negative charge.

Zetasizer WT also allows easy measurement of grab samples from other areas in the process, effectively doubling as a laboratory system.

Technical Specification

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Sample requirement

Sample flow rate: 100 - 350 LPH (fast loop)

Sample flow rate: 0.5 - 2 LPM (measurement)


Measurement type: Zeta potential

Measurement principle: Laser Doppler micro-electrophoresis



Result output frequency: 3 minutes typical, programmable

Operation: 24hr continuous

Range of zeta potential measurement: +/- 500 mV (+/- 90 mV on HMI interface)



Size range: 3.8 nm to 100µm

Enclosure rating: IP54, indoor use. Limited capability to NEMA 4X

Power: 90 - 132 VAC, 180 - 264 VAC, 50 - 60 Hz, 6 A

Dimensions (W, D, H): 855 x 686 x 1720mm

Weight: 160 Kg

Compressed air purge: 1.5LPM, 6-10 bar, ISO 8573-1:2010 [0.7.2] (optional)


Operating environment

Temperature range: 0°C to 40°C

Humidity: 5-95% non-condensing

Maximum sample pressure: 6 bar

Zetasizer WT


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