AquaScat 2 WTM | True non-contact turbidity meter (ISO 7027)

The Sigrist AquaScat 2 WTM is a high-precision on-line turbidity meter engineered for continuous monitoring of water quality in drinking water, wastewater, and industrial process applications. Built around the 90° scattered light measuring principle in accordance with ISO 7027 / EN 27027, the AquaScat 2 WTM delivers exceptional accuracy through a unique non-contact free-fall measurement design.

Furthermore, the AquaScat 2 WTM is available in two variants. The standard WTM model uses a solid reference for manual recalibration, while the WTM A model adds fully automatic calibration for measuring points that are difficult to access or unattended.

Across the water treatment industry, the AquaScat 2 WTM supports a wide range of monitoring tasks, including:

• Turbidity in raw water intake
• Turbidity in the sedimentation stage and dosing of flocculant
• Turbidity before and after membrane filtration
• Turbidity before and after disinfection
• Turbidity in drinking water before feeding into the distribution network
• Turbidity measurement in process water and wastewater

As a result, the AquaScat 2 WTM has become a trusted choice for water utilities, treatment plant operators, and process engineers managing critical water quality control points.

Unlike traditional turbidity meters, the AquaScat 2 WTM measures turbidity in a free-falling water jet. Because the water never touches the optical windows, contamination is eliminated and maintenance drops to an absolute minimum.

In addition, this contactless design delivers several practical advantages:

• No window fouling, which means precise high and low turbidity measurement over time
• Representative results from measuring the entire sample stream
• Suitable for difficult raw water with high contamination levels
• Reduced cleaning intervals and lower lifecycle costs

Consequently, water treatment operators benefit from accurate readings without the manual cleaning and frequent service visits associated with conventional optical sensors.

Built for demanding water quality control, the AquaScat 2 WTM features an extremely low inherent brightening effect. Therefore, it can detect even the smallest changes in turbidity, making it ideal for monitoring filtration performance and disinfection breakthrough.

Furthermore, an extremely stable zero point ensures reliable long-term measurement without drift. As a result, the AquaScat 2 WTM is well suited to both demanding process controls and challenging raw water monitoring, where stability over months of operation is essential.

The AquaScat 2 WTM is factory calibrated with formazin. For ongoing recalibration during operation, however, a secondary turbidity standard (solid reference) is used instead. Consequently, operators can perform precise recalibration without handling toxic formazin solutions.

In addition, the solid reference offers several practical benefits:

• Stable optical properties that do not change over time
• Repeatable, comparable verification results
• Low time expenditure during routine calibration checks
• Safer working environment with no toxic chemicals on site

For unattended or hard-to-access installations, the AquaScat 2 WTM A model adds fully automatic calibration with a solid reference. Therefore, no on-site personnel are required to perform routine verification.

Key benefits of the WTM A variant include:

• Precise recalibration without toxic formazin
• No need to switch off the water supply during calibration
• Ideal for remote measuring points and unattended treatment plants
• Continuous, hands-off operation with verified accuracy

As a result, the WTM A model significantly reduces operational workload for water utilities running distributed monitoring networks.

Integrated Touchscreen Operating Unit

To make day-to-day operation straightforward, the AquaScat 2 WTM A features a 3.5″ colour touchscreen display. In addition, the integrated operating unit provides:

• On-screen display of measurement values, status, and alarm messages
• Graphical trend visualisation directly on the device
• Internal data memory for the last 32 days of measurement data
• Intuitive menu navigation via touchscreen

Consequently, operators can review recent trends, troubleshoot issues, and verify performance without connecting an external laptop or control room interface.

To suit any process control architecture, the AquaScat 2 WTM offers a wide range of integration options:

• Analogue outputs: 2 × 0/4–20 mA, galvanically isolated
• Relay outputs: 2 × 250 VAC, 4 A
• Digital interfaces: Ethernet, Modbus TCP, SD card as standard
• Optional fieldbus: Profibus DP, Profinet IO, Modbus RTU
• Additional inputs: flow meter, 2 × 0/4–20 mA
• Optional sensors: pH, conductivity, ORP, and dissolved oxygen (DO)

Furthermore, the AquaScat 2 WTM can act as a multi-parameter station by combining turbidity with optional water quality sensors, which reduces panel space and simplifies integration with SCADA and PLC systems.

Below are the key technical specifications for the AquaScat 2 WTM on-line turbidity meter:

Throughout Australia, New Zealand, and internationally, the AquaScat 2 WTM on-line turbidity meter is widely used across:

• Drinking water treatment and distribution
• Municipal and industrial wastewater treatment
• Process water in manufacturing and food production
• Pre- and post-filtration monitoring (sand, membrane, UF, RO)
• Disinfection and UV system monitoring
• Reservoir and distribution network quality control

As the Australian and New Zealand partner for Sigrist-Photometer, ProDetec supplies the AquaScat 2 WTM and AquaScat 2 WTM A with full local technical support, installation guidance, commissioning, and ongoing service. Whether you are monitoring raw water intake, verifying filtration performance, or maintaining drinking water quality before network distribution, the AquaScat 2 WTM delivers Swiss-engineered precision backed by trusted local expertise.