The ST-500 Inline PTSA Sensor gives operations teams a continuous, real-time reading of inhibitor concentration in fluorescence-traced water treatment programmes. Rather than relying on periodic manual sampling, the sensor feeds directly into dosing control logic, keeping the treatment concentration within a tight band around the setpoint regardless of changes in cycles of concentration or heat load.

Its flow-through optical design uses multi-wavelength fluorescence measurement to compensate for colour and turbidity interference, an area where many competing sensors lose accuracy. The ST-500 maintains performance in samples with up to 100 NTU turbidity and 5ppm iron, conditions that would otherwise distort a standard fluorometer reading.

Beyond PTSA, the ST-500 series extends to fluorescein and naphthenic disulfonic acid (NDSA), making it suitable for boiler water treatment programmes as well as cooling tower applications.

Add the MA-WB Bluetooth Adapter for wireless calibration, cleanliness diagnostics, and monitoring via the uPyxis mobile app.

Key specifications:

• PTSA range: 0–300ppb (via uPyxis app), 0–200ppb output scale
• Accuracy: ±1ppb
• Outputs: isolated 4-20mA analog and isolated RS-485 digital
• Installation: ST-001 inline tee (included), 3/4″ FNPT
• Material: CPVC, IP67 rated
• Operating temperature: 4-49°C
• Power: 22-26VDC, 1W