Nexisense Water-Based Carbon Monoxide Sensor: Industrial System Integration Solution

Nexisense water-based electrochemical carbon monoxide (CO) sensor module is developed for B2B industrial integration scenarios, providing a highly reliable, low-maintenance, and easily integrable sensing layer solution. This module is designed for industrial IoT, system integrators, and engineering projects, utilizing sealed aqueous electrolyte technology combined with high-stability catalytic electrodes and intelligent compensation algorithms. This article outlines its technical advantages, typical applications, selection guidelines, integration considerations, and project references from a system integration perspective to assist procurement and engineering teams in efficient decision-making.

Core Technical Principles and Engineering Advantages of Water-Based Electrochemical CO Sensors

The Nexisense water-based CO sensor is based on a three-electrode electrochemical system (working electrode, counter electrode, reference electrode), using environmentally friendly aqueous electrolytes (sulfuric acid-based or neutral buffer) as ion conduction media, avoiding volatilization, flammability, and long-term drift issues of traditional organic electrolytes.

Core electrochemical reactions are as follows:

• Working Electrode (Anode): CO + H₂O → CO₂ + 2H⁺ + 2e⁻

• Counter Electrode (Cathode): ½O₂ + 2H⁺ + 2e⁻ → H₂O

This reaction occurs under constant potential mode, with output current (typical nA/ppm) linearly correlated to CO concentration. The reference electrode ensures potential stability and eliminates background drift.

Comparison with Traditional MOS Sensors

Typical Application Scenarios from a System Integrator Perspective

1. Hazardous Chemicals and Energy Storage Facilities
   In petrochemical storage areas, LNG receiving stations, and coal chemical parks, CO is often generated alongside leaks or incomplete combustion. Nexisense sensors can be integrated into fixed gas monitoring systems, linked with combustible gas, H₂S, and O₂ sensors, and connected to upper-level systems or DCS via Modbus RTU for multi-point deployment and concentration trend analysis. In actual projects, deployed in multiple Sinopec and CNPC storage/transport projects, the average false alarm rate is below 0.5%.

2. Metallurgy and Heat Treatment Workshops
   Processes such as blast furnaces, converters, annealing furnaces, and hot-dip galvanizing lines generate CO. Sensor modules can be embedded in ventilation interlock systems; when concentration >50 ppm, forced ventilation or shutdown signals are triggered. Nexisense supports custom alarm thresholds and hysteresis, compatible with SIL2 safety instrumented systems.

   
   

3. Underground Spaces and Tunnel Projects
   CO accumulation risk is high in underground parking lots, subway sections, utility corridors, and civil defense spaces. IP67 modules can be directly installed in ventilation shafts or pipelines, connected with LoRa/4G/NB-IoT gateways for wireless networking, uploading data to cloud platforms for AI anomaly detection and predictive maintenance.

4. Boiler Rooms and CHP Projects
   Gas/coal boiler exhaust leakage is a major CO source. Sensors can be integrated into boiler control cabinets via 4–20 mA analog output directly to PLCs, enabling automatic fuel shut-off when concentrations exceed limits. Multiple CHP projects show zero-point drift <±2 ppm/year under -10–45℃ when combined with temperature/humidity compensation.

Selection Guide: Key Parameters and Matching Recommendations

1. Range Selection

• Typical industrial scenario: 0–500 ppm / 0–1000 ppm

• High-risk areas (e.g., metallurgy): 0–2000 ppm

• Low concentration warning (e.g., underground spaces): 0–200 ppm (resolution 0.1 ppm)

2. Output Interfaces

• 4–20 mA (two-wire/three-wire): Most common PLC/SCADA integration

• RS485 Modbus RTU: Supports up to 247-node networking, recommended for IoT

• UART/I²C: Suitable for embedded gateways or MCU development

3. Protection Level and Environmental Adaptation

• IP65: Indoor/semi-outdoor

• IP67: Humid or dusty environments (e.g., wastewater treatment)

• Explosion-proof: Ex d IIC T6 Gb (customized)

4. Power Supply and Consumption

• 12–24 V DC (industrial standard)

• Ultra-low power version (<0.5 mW) suitable for battery/solar nodes

5. Additional Features

• Built-in temperature compensation curve (-20–50℃)

• Automatic baseline calibration (daily/weekly)

• Lifetime diagnostic output (via Modbus registers to estimate remaining life)

  
  

System Integration Considerations and Best Practices

1. Installation Location and Diffusion Path
   CO density is slightly lower than air; recommended installation height: 1.5–2.0 m from floor, or 30–50 cm above potential leak sources. Avoid direct water or oil mist impacting the breathable membrane.

2. EMC and Wiring
   RS485 bus recommended with shielded twisted pair, properly grounded; 4–20 mA loop should avoid parallel routing with high-voltage lines longer than 10 m.

3. Calibration and Verification
   Recommend annual on-site Bump Test (standard gas verification) + full-range calibration every 2 years. Nexisense modules support zero/span software calibration and remote Modbus operation.

4. Redundancy and Fault Tolerance
   Critical areas suggest 2oo3 or 1oo2 voting logic to enhance system availability.

5. Data Integration and Protocol Conversion
   For projects using BACnet, OPC UA, etc., Nexisense compatible gateways allow seamless protocol conversion.

FAQ

1. Does the Nexisense water-based CO sensor require periodic electrolyte replacement?
   No. Fully sealed slow-release design ensures electrolyte life matches the sensor life (≥5 years). Replace module when expired.

2. Is it reliable in high humidity environments (e.g., wastewater treatment plants)?
   Supports IP65/IP67 protection, internal humidity compensation ensures cross-error <±3 ppm within 15–95% RH. Avoid direct condensation on breathable membrane.

3. How to configure Modbus address when integrating with PLC/SCADA?
   Default slave address: 1. Supports 0x03/0x06/0x10 function codes. Concentration value located in register 40001 (16-bit unsigned, unit 0.1 ppm). Full mapping table in manual.

4. How to monitor sensor life?
   Read “remaining life percentage” or “drift value” via Modbus registers; APP/host can set threshold warning (e.g., alarm if <20%).

5. Does it support explosion-proof certification?
   Standard version: industrial type; explosion-proof (Ex d IIC T6 Gb) available per project requirements; prior consultation needed.

6. How to handle long-term zero-point drift?
   Built-in daily automatic baseline calibration (zeroed in CO-free environment), combined with temperature compensation; typical annual drift <±5 ppm.

7. Can it share the same bus with combustible gas, H₂S sensors?
   Yes, as long as Modbus addresses do not conflict; multi-device network up to 247 nodes.

8. Sample testing and bulk delivery cycle?
   Samples: 7–14 days; bulk orders (>500 pcs): 4–6 weeks; long-term framework agreements and custom development supported.

Conclusion

Nexisense water-based carbon monoxide sensors provide high selectivity, long life, low power consumption, and multiple communication interfaces, offering a reliable sensing foundation for industrial gas monitoring system integration. Whether deploying multi-parameter networks in hazardous chemical parks, metallurgical process safety interlocks, or smart ventilation in underground spaces, this sensor series significantly reduces false alarms, lowers maintenance costs, and helps projects pass safety evaluation and acceptance.

As a system integrator or engineering company partner, we welcome you to contact the Nexisense technical team (email/phone on official website) for complete datasheets, sample testing support, or customized solutions for specific projects. Let’s work together to provide more stable and intelligent industrial safety monitoring solutions.