News Details

KNF Releases KNF-400PRO RS485 Digital Water Quality Sensor

KNF Sensors has officially released the KNF-400PRO, an integrated RS485 digital water quality sensor built for continuous, unmanned online monitoring in the world's most demanding water environments. By combining six measurement parameters — dissolved oxygen, pH, conductivity, turbidity, depth and temperature — into a single compact probe body, the KNF-400PRO eliminates the complexity of multi-instrument installations and sends all data over one RS485 bus using the standard MODBUS protocol.

One Probe Instead of Six Instruments

Traditional water quality stations depend on separate analyzers, individual transmitters, junction boxes and extensive cabling. Every additional device adds a failure point, another calibration schedule and another source of measurement drift. The KNF-400PRO replaces that entire stack with a single fully digital sensor, allowing system integrators to commission a complete monitoring point in hours instead of days.

The probe is equipped with an automatic cleaning brush that sweeps the measurement surface, removes air bubbles and inhibits microbial growth. Factory default cleaning is every 30 minutes, and the interval can be customized to match site conditions. Combined with a maintenance cycle of several months, this design keeps long-term online readings stable while dramatically reducing manual cleaning visits.

Key Advantages

• Six parameters in one integrated body — dissolved oxygen, pH, conductivity (with salinity and TDS), turbidity, depth and temperature
• RS485 digital output with standard MODBUS protocol for direct connection to data loggers, RTUs, PLCs and cloud monitoring platforms
• Self-cleaning brush that prevents biological adhesion and sediment build-up, lowering maintenance cost
• On-site calibration — calibration data is stored inside the probe, so the whole unit can be calibrated quickly in the field
• Direct immersion, IP68 protection — suitable for all-weather, uninterrupted deployment in rivers, tanks and coastal water
• Low power draw of 0.8 W without brush rotation and 2 W with the brush running, well suited to solar and battery-powered stations

Technical Specifications

Measurement Performance

Typical Applications

• Wastewater treatment plants and effluent discharge monitoring
• Surface water, rivers and reservoir monitoring
• Marine, coastal and aquaculture water quality monitoring
• Groundwater and drinking water source monitoring
• Industrial process water and smart city environmental networks

Availability

The KNF-400PRO is manufactured under ISO 9001 quality management in Guangdong, China, with a minimum order quantity of one piece and a supply capacity of up to 1,000 pieces per month. Standard delivery is 7-15 working days, and each sensor ships in KNF branded export cartons with shock-proof foam, a 65 mm x 430 mm probe and a 10-meter waterproof cable. OEM and ODM customization, bulk pricing and technical support are available on request from the KNF sales team.