How Is Water Quality Data Collected?
Water quality data is obtained by placing sensors directly in contact with — or optically through — a water sample. Each sensor targets one or more specific parameters and converts a physical or chemical property of the water into a measurable electrical or optical signal. That signal is processed internally and transmitted as digital data to a controller, data logger, or cloud platform.
There are three core sensing technologies that cover the majority of water quality parameters:
Electrochemical sensors measure the electrical response of a specialized electrode in contact with the water — used for pH, ORP, dissolved oxygen (polarographic), residual chlorine, and ion-specific parameters like ammonia nitrogen, nitrate, chloride, and fluoride.
Optical / fluorescence sensors direct light through or into the water and measure what comes back — used for dissolved oxygen (fluorescence quenching), turbidity (scattered light), chlorophyll, blue-green algae, and oil-in-water.
UV absorption sensors measure how much ultraviolet light is absorbed as it passes through the water sample — used for COD, TOC, and BOD, where organic compounds absorb UV at 254 nm.
All three technologies can be packaged in a single submersible digital sensor module with RS-485 Modbus RTU output — ready to connect to any monitoring system or cloud platform.
Recommended Kainafu Sensors for Water Quality Data Collection
1. KNF-2100Pro — Multi-Parameter Sensor (Collect 15+ Parameters at Once)
If the goal is to collect comprehensive water quality data from a single deployment point, the KNF-2100Pro is the most efficient answer. One submersible probe simultaneously measures up to 15 parameters — covering electrochemical, optical, and pressure-based sensing in a single Φ63/75 mm housing on a single RS-485 cable.
Parameters available: temperature, pH, ORP, conductivity, TDS, dissolved oxygen, turbidity, oil-in-water, ammonium ion, nitrate, chloride, fluoride, potassium, sodium, water level
| Specification |
Value |
| Parameters |
Up to 15 (customer-configurable) |
| DO method |
Fluorescence (no membrane/electrolyte) |
| Protection |
IP68, 30 m depth |
| Output |
RS-485 Modbus RTU |
| Housing |
316 stainless steel, Φ63/75 mm × 294 mm |
| Power |
12/24V DC, 1.5W |
| Cleaning |
Built-in mechanical brush (optical electrodes) |
Best for: Groundwater monitoring wells, river cross-section buoys, lake profiling, comprehensive water quality surveys, emergency pollution investigation
2. KNF-108A — UV COD Sensor (Collect Organic Pollution Data)
For collecting data on organic pollution load — the single most important parameter at wastewater discharge points and polluted river sections — the KNF-108A UV absorption COD sensor provides real-time COD, TOC, and turbidity data with no reagents and no sampling delay.
Traditional laboratory COD testing takes 2–4 hours and produces hazardous chemical waste. The KNF-108A delivers the same data continuously, in under 10 seconds, 24 hours a day.
| Specification |
Value |
| Parameters |
COD + TOC + turbidity (simultaneous) |
| COD range |
0.75–450 mg/L (customizable to 1,500 mg/L) |
| Accuracy |
<5% equiv. KHP |
| Housing |
316L stainless steel, IP68 |
| Self-cleaning |
Integrated brush |
| Output |
RS-485 Modbus RTU |
| Power |
DC <50 mA |
Best for: Wastewater treatment effluent, industrial discharge monitoring, river pollution cross-sections, sewage network nodes
3. KNF-505 — Integrated Multi-Parameter Sensor (6 Core Parameters)
For standard water quality data collection covering the six most commonly required parameters, the KNF-505 integrates pH, dissolved oxygen, ORP, conductivity/salinity, turbidity, and temperature in a single submersible housing with an automatic self-cleaning device.
Simpler than the KNF-2100Pro and lower cost, the KNF-505 is the practical choice when comprehensive multi-parameter data collection is needed without the full 15-parameter capability.
| Monitoring Parameter |
Range |
Accuracy |
| pH |
0–14 |
±0.1 pH |
| Dissolved Oxygen |
0–20 mg/L |
±2% F.S. |
| Turbidity |
0–1,000 NTU |
±5% F.S. |
| Conductivity / Salinity |
0–5,000 μS/cm |
±1.5% F.S. |
| ORP |
-1,500 to +1,500 mV |
±6 mV |
| Temperature |
0–50°C |
±0.3°C |
- Output: RS-485 Modbus RTU | Power: 12–24V DC
- Cleaning: Automatic brush with adjustable interval
- Cable: 10 m standard (customizable)
Best for: Environmental monitoring stations, water supply and drainage networks, ecological surveys, aquaculture systems
Which Sensor Collects Which Data — Quick Reference
| Water Quality Data Needed |
Best Kainafu Sensor |
| 15+ parameters at one point |
KNF-2100Pro |
| COD / TOC / organic load |
KNF-108A |
| 6 core parameters (pH, DO, turbidity, conductivity, ORP, temp) |
KNF-505 |
| pH only |
KNF-101PRO |
| Dissolved oxygen only |
KNF-103B |
| Residual chlorine only |
KNF-1005D |
| Turbidity / SS only |
KNF-1004Pro |
About Kainafu
Shenzhen Kainafu Technology Co., Ltd. is an ISO 9001 and CMA-certified R&D manufacturer producing 50+ digital water quality sensor types entirely in-house in Shenzhen, China. All sensors output RS-485 Modbus RTU and connect to the Kainafu cloud monitoring platform at ion.onetestinc.com — real-time data, threshold alarms, and compliance reporting from any device.
📧 Email: knfeco@knfsensors.com 🌐 Website: www.knfsensors.com
Shenzhen Kainafu Technology Co., Ltd. — Care for Environments and Health.
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