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What Makes a Water Quality Sensor "Digital"?

A digital online water quality sensor integrates the measurement electrode, signal amplification, analog-to-digital conversion, temperature compensation, and communication interface all within a single waterproof housing. The sensor outputs a processed, calibrated measurement value directly as a digital signal — most commonly via RS-485 with Modbus RTU protocol.

This is a fundamental advantage over older analog sensors that output a raw millivolt or 4–20 mA signal:

For any serious online water quality monitoring application — whether a single monitoring point or a network of 50 sensors — digital RS-485 sensors are the professional standard.

Kainafu — One Brand, Every Digital Sensor You Need

Shenzhen Kainafu Technology Co., Ltd. manufactures over 50 types of digital water quality sensors covering every major parameter — all with RS-485 Modbus RTU output, all IP68 rated, all reagent-free, and all produced in our own Shenzhen R&D facility under ISO 9001 quality management.

Whether you need a single pH sensor or a complete multi-point monitoring network covering pH, DO, COD, turbidity, ammonia nitrogen, residual chlorine, conductivity, and ions — Kainafu supplies every sensor from one manufacturer, on one protocol, through one point of contact.

4 Digital Sensors That Define the Kainafu Range

1. KNF-101PRO — Digital pH / ORP Sensor

The most universally required parameter in water quality monitoring. The KNF-101PRO measures pH (0–14, ±0.02 accuracy) and ORP (±1,000 mV) simultaneously in one digital module. Ceramic sand core junction for biofouling resistance. Supports pipeline and submersible installation. Remote calibration via RS-485 — no need to retrieve the sensor from the water.

• Output: RS-485 Modbus RTU | Power: 5–30 VDC, <10 mA
• Protection: IP68, 6 bar / 50 m
• Applications: Drinking water, wastewater, aquaculture, industrial process water

2. KNF-103B — Digital Dissolved Oxygen Sensor

Based on fluorescence quenching technology — no membrane replacement, no electrolyte, unaffected by H₂S, ammonia, or heavy metals. Sensor drift is less than 1% per year. Response time under 10 seconds. Built-in temperature compensation. The most maintenance-free DO sensor technology available.

• Range: 0–20 mg/L | Accuracy: ±1% | Drift: <1%/year
• Output: RS-485 Modbus RTU | Protection: IP68
• Applications: Aeration basin control, aquaculture, river monitoring, wastewater treatment

3. KNF-1008APro — Digital COD Smart Sensor

Dual-wavelength UV absorption at 254 nm + 546 nm simultaneously measures COD, BOD, TOC, and turbidity from one probe — with automatic color and turbidity interference compensation. No reagents, no digestion, <10 second response. Integrated self-cleaning brush for long-term unattended deployment.

• COD range: 0–200 / 0–1,000 mg/L | Accuracy: ±5% or 3 mg/L
• Output: RS-485 Modbus RTU | Power: 12/24V DC, 0.4W
• Applications: Effluent compliance, surface water, sewage network, small monitoring stations

4. KNF-1004Pro — Digital Turbidity Sensor

Infrared light source compliant with ISO 7027 and USEPA 180.1 — unaffected by water sample color. Integrated self-cleaning brush. Available in 0–1,000 NTU and 0–4,000 NTU ranges. Included data analysis software with calibration, logging, and diagnostic functions.

• Accuracy: ±3% or 3 NTU | Response: <10 s
• Output: RS-485 Modbus RTU | Power: 12/24V DC, 0.6W
• Applications: Waterworks, wastewater treatment, construction site discharge, surface water

The Full Kainafu Digital Sensor Lineup

These four sensors represent just the starting point. Kainafu's complete digital sensor range covers:

Every single model outputs RS-485 Modbus RTU. Mix and match any combination on a single bus — or integrate into any Kainafu KNF-400 monitoring system or third-party SCADA with zero protocol conversion.

Why Buying a Full Range from One Brand Matters

Sourcing digital water quality sensors from multiple suppliers creates real operational problems — different protocols, different calibration software, different technical support contacts, different spare parts. When one sensor fails at 2am, you need one phone call.

Kainafu's single-brand, single-protocol approach means:

• ✅ All sensors calibrated through the same cloud-based software
• ✅ All data on one platform — ion.onetestinc.com
• ✅ One factory, one technical support team
• ✅ ISO 9001 quality management across every product line
• ✅ OEM and customization from a single manufacturing partner