News Details

What Is a pH Sensor Module?

A pH sensor module is a self-contained measurement unit that combines a pH-sensitive electrode, reference electrode, signal conditioning electronics, and communication interface in a single waterproof housing — ready to install and connect directly to a data logger, PLC, SCADA system, or cloud monitoring platform.

Unlike basic laboratory pH electrodes that output a raw millivolt signal requiring an external transmitter, a digital pH sensor module converts the electrode signal internally and outputs clean digital data via RS-485 or 4–20 mA — eliminating signal noise over long cable runs and simplifying system integration.

For industrial and environmental water quality monitoring, a quality pH sensor module must deliver:

• Stable, accurate readings over weeks and months of continuous deployment
• Robust waterproofing against immersion, pressure, and outdoor conditions
• Digital output immune to electromagnetic interference
• Low maintenance — minimal calibration frequency and easy electrode servicing
• Installation flexibility — compatible with both submersible and pipeline mounting

The Kainafu KNF-101PRO is designed to meet all of these requirements.

Introducing the KNF-101PRO pH Sensor Module

The KNF-101PRO is Kainafu's flagship digital pH/ORP sensor module — the result of multiple design iterations based on extensive real-world installation experience across industrial, municipal, and environmental water quality monitoring applications. It measures pH and ORP simultaneously in a single compact module, with RS-485 Modbus RTU digital output and IP68 protection rated to 6 bar pipeline pressure and 50 metres submersible depth.

Full Technical Specifications

Key Features of the KNF-101PRO Module

✅ Dual-Mode Installation — Pipeline and Submersible

Most pH sensor modules are optimised for one installation type. The KNF-101PRO supports both:

• Submersible — direct immersion in open channels, tanks, rivers, ponds, and reservoirs
• Pipeline — using an optional Y-type 3-way fitting with end face seal for pressurised pipe installation up to 6 bar

One module, two installation modes — covering the full range of industrial and environmental pH monitoring scenarios without purchasing separate products.

✅ RS-485 Digital Output — Clean Signal Over Long Cable Runs

The KNF-101PRO transmits all measurement data digitally via RS-485 — immune to the electromagnetic interference generated by pumps, motors, variable frequency drives, and other industrial equipment common in water treatment and industrial environments. Up to 255 sensor modules can share a single RS-485 bus, each with a unique Modbus address — ideal for multi-point monitoring networks where cable infrastructure must be minimised.

✅ Remote Calibration via RS-485

Calibration and parameter adjustments are performed remotely via RS-485 commands — without physically accessing the sensor or retrieving it from the water. For sensors installed in pipelines, underground chambers, or hard-to-reach locations, this is a significant operational advantage.

✅ Ceramic Sand Core Liquid Junction

The single-point ceramic sand core liquid junction is selected for its superior resistance to biofouling, suspended solids, and chemical fouling — the most common causes of premature pH electrode failure in industrial and wastewater applications. A double salt bridge option is available for particularly challenging sample chemistries.

✅ Independent Electrolyte Filling Port

A dedicated electrolyte filling port allows field technicians to top up the reference electrolyte without removing or replacing the electrode assembly — extending electrode service life and reducing consumable costs significantly compared to sensors requiring full electrode replacement at every service.

✅ No Reagents Required

The KNF-101PRO operates entirely without chemical reagents — no buffer solutions are needed during normal operation, only for periodic calibration. This makes it safe for unattended deployment and eliminates ongoing chemical procurement and handling costs.

Integration with Controllers and Cloud Platforms

The KNF-101PRO pH sensor module integrates directly with:

All data connects to the Kainafu cloud platform at ion.onetestinc.com — real-time dashboards, configurable alarms, historical trends, and compliance reporting via web, iOS/Android APP, and WeChat.

Application Scenarios

Drinking water distribution — pH compliance monitoring at pump stations and network end-points

Wastewater treatment — pH control in equalisation basins, biological reactors, and effluent discharge

Industrial process water — chemical dosing control, cooling water, electroplating, food and beverage

Aquaculture — continuous pond and tank pH monitoring for fish and shrimp health

Surface water monitoring — submersible deployment in rivers, lakes, and reservoirs

Secondary water supply — pH monitoring in building pump rooms and rooftop tanks

Why Choose Kainafu

Shenzhen Kainafu Technology Co., Ltd. is an ISO 9001 and CMA-certified R&D manufacturer based in Shenzhen, China. The KNF-101PRO is designed, manufactured, and calibrated entirely in-house — available factory direct with full engineering support, OEM customization, and no intermediary markup.

📧 Email: knfeco@knfsensors.com 🌐 Website: www.knfsensors.com