Multi-Parameter Controller
The S-ORP042 ORP sensor operates on electrochemical principles, employing a matched pair of a platinum measuring electrode and a stable reference electrode to deliver precise, linear oxidation-reduction potential (ORP) measurement across a wide range of aqueous media. Engineered with an industrial-grade electrode core, the sensor incorporates automatic temperature compensation (ATC) and digital signal processing to ensure consistent measurement accuracy across varying process conditions.
Digital output is delivered via RS-485 using the standard Modbus RTU protocol, enabling seamless integration with PLCs, SCADA systems, data loggers, and other networked industrial terminals — with no analog signal conversion required.
ORP (also referred to as Redox Potential) is a critical water quality parameter used to assess the oxidizing or reducing capacity of a solution. It is widely applied in disinfection control, water treatment process optimization, aquaculture management, and industrial effluent monitoring.
| Application | Typical Use Case |
| Surface water monitoring | Rivers, lakes, reservoirs — ecological and regulatory compliance |
| Raw water intake monitoring | Pre-treatment quality screening at water source intake points |
| Water & wastewater treatment | Oxidation process control, chlorination, and dechlorination stages |
| Drinking water monitoring | Disinfection byproduct control and distribution network quality assurance |
| Municipal sewage treatment | Biological treatment process optimization (aerobic/anoxic control) |
| Industrial discharge / effluent outfall | Pollution source monitoring at discharge points |
| Secondary water supply systems | Booster pump stations and building water supply monitoring |
| Swimming pool & recreational water | Disinfectant dosing control and water hygiene compliance |
| Parameter | Specification |
| Model | S-ORP042 |
| Measured Parameters | ORP, Temperature |
| Measurement method | Platinum electrode method |
| ORP Range | −2,000 to +2,000 mV |
| Temperature Range | 0 – 65 °C |
| Resolution | 0.1 mV |
| Accuracy | ≤ ±20 mV |
| Repeatability | ≤ ±1 mV |
| Response Time | ≤ 10 s |
| Drift | ≤ ±1 mV/period |
| Calibration Interval | 3 months (or as required by site conditions) |
| Operating Temperature | 0 – 65 °C |
| Ingress Protection | IP68 |
| MTBF | ≥ 1,440 hours |
| Installation Method | Flow-through (flow cell) / Submersion (immersion) |
| Communication Protocol | RS-485 (Modbus RTU) |
| Supply Voltage | 9 – 30 V DC |
| Housing Material | ABS |
| Weight | 500 g |
| Signal Cable | 5 m (standard); custom lengths available on request |
Q1: What is ORP and why does it matter in water quality monitoring?ORP (Oxidation-Reduction Potential), also known as Redox Potential, measures the tendency of a solution to gain or lose electrons — in practical terms, it quantifies the oxidizing or reducing strength of the water. In water treatment, ORP is a direct indicator of disinfection effectiveness: a sufficiently positive ORP value (typically above +650 mV for chlorinated systems) confirms that pathogens are being effectively neutralized. It is also used to monitor denitrification processes, aquaculture health, and industrial chemical treatment stages.
Q2: What is the difference between the S-ORP042 and the S-ORP041?Both sensors use platinum electrode technology and RS-485 Modbus RTU output. The S-ORP042 is the standard standalone ORP sensor. For applications requiring simultaneous pH and ORP measurement from a single probe insertion point, consider the S-ORP043 pH/ORP 2-in-1 Sensor, which reduces installation complexity and maintenance overhead.
Q3: Does the S-ORP042 require temperature compensation?ORP measurement is less temperature-sensitive than pH, and the S-ORP042 does not apply the same ATC correction algorithm used in pH sensors. However, the onboard temperature reading is available via Modbus registers and can be used by your control system for process correlation or data logging purposes.
Q4: How do I calibrate the S-ORP042?The S-ORP042 is calibrated using a certified ORP standard solution (typically +220 mV or +468 mV Zobel solution at 25 °C). Calibration is performed via the Modbus RTU interface using a compatible controller or configuration tool. Under normal conditions, recalibration every 3 months is recommended; in aggressive or high-fouling media, more frequent calibration intervals may be required.
Q5: Is the S-ORP042 compatible with third-party PLCs and SCADA systems?Yes. The standard Modbus RTU protocol over RS-485 (2-wire) ensures out-of-the-box compatibility with major industrial platforms including Siemens S7, Schneider Modicon, Allen-Bradley, Ignition SCADA, and WinCC. Full register maps are provided in the product documentation.
