CO2-100 Dissolved CO2 Sensor - 0.2-2,200 ppm, RS485

Overview

The CO2-100 is an advanced gas-sensing electrode specifically designed for measuring dissolved carbon dioxide (CO2) in water. This sensor is essential for applications where CO2 levels significantly impact product quality, organism health, or process efficiency, including aquaculture, beverage production, biogas plants, and pharmaceutical manufacturing.

Key Features

• Gas-Sensing Technology: Measures dissolved CO2 directly in water
• Wide Range: 0.2 to 2,200 ppm, configurable to 20,000 ppm
• High Resolution: 0.01 ppm resolution at ±5% FS accuracy
• Digital Output: RS485 Modbus RTU for seamless integration with SCADA and IoT systems
• Automatic Temperature Compensation: Integrated NTC10K sensor for accurate readings
• Direct Connection: Connect directly to computer or PLC without additional instrumentation
• Durable Housing: Corrosion-resistant PPS body with NPT 3/4” threaded fittings

Applications

• Aquaculture and fish farming
• Shrimp and crustacean farming
• Beverage carbonation monitoring
• Brewery fermentation control
• Wine production
• Soft drink manufacturing
• Biogas production monitoring
• Anaerobic digestion processes
• Pharmaceutical fermentation
• Cell culture and bioreactors
• Water treatment plants
• Swimming pool water quality

Technical Specifications

The CO2-100 delivers precise dissolved CO2 measurements from 0.2 to 2,200 ppm, configurable to 20,000 ppm, with automatic temperature compensation via the integrated NTC10K sensor. The gas-sensing membrane selectively detects CO2 molecules that diffuse across the membrane, providing accurate measurements independent of other dissolved gases.

Understanding Dissolved CO2

Carbon dioxide in water is important for several reasons:

Aquaculture

• Fish Health: Elevated CO2 (>20 mg/L) can stress fish and reduce oxygen uptake
• pH Impact: CO2 forms carbonic acid, lowering pH
• Water Quality: Indicator of organic load and respiration rates

Beverage Industry

• Carbonation Levels: Critical for product consistency and taste
• Fermentation Monitoring: Tracking CO2 production during brewing
• Quality Control: Ensuring proper carbonation in finished products

Bioprocessing

• Fermentation Control: Monitoring microbial activity
• Cell Culture: Maintaining optimal CO2 for cell growth
• Process Optimization: Maximizing productivity

pH and Temperature Effects

CO2 solubility is affected by:

• Temperature: Higher temperature reduces CO2 solubility
• Pressure: Higher pressure increases CO2 solubility
• pH: CO2 affects water pH and exists in equilibrium with bicarbonate and carbonate

The CO2-100’s automatic temperature compensation ensures accurate measurements across varying conditions.

Connectivity and Integration

The CO2-100 communicates over RS485 Modbus RTU for flexible integration across aquaculture, beverage, and bioprocess systems:

RS485 Modbus RTU:

• Connect to Agrinovo Omni Genesis or Exodus controllers for cloud-based CO2 monitoring
• Multi-drop bus networking (multiple sensors per bus)
• Standard Modbus registers for CO2 concentration and temperature
• Compatible with SCADA, PLC, brewery automation, and fermentation control systems

IoT Integration:

• Pair with Omni Genesis/Exodus for automated CO2 alerts and trend logging
• Trigger emergency aeration when CO2 exceeds safe thresholds in fish tanks
• Monitor fermentation progress remotely in beverage production
• Historical data analysis for process optimization

Installation and Maintenance

Positioning: Install in a representative flow area where CO2 levels reflect actual conditions. In aquaculture, position away from aeration diffusers (which artificially lower local CO2). In fermentation vessels, install below the liquid surface in a well-mixed zone. For valid readings, keep the sample pH between 4.8 and 5.2.

Calibration: Multi-point calibration (up to 5 points) using CO2 standard solutions at 0.1, 1, 10, 100, and 1,000 ppm, performed over RS485. Recalibrate periodically against standards.

Membrane Care: The gas-permeable membrane is the key sensing element. Clean monthly to remove biofilm and organic deposits. Replace the membrane cap when response time degrades or calibration slopes decline. Membrane life depends on water quality and fouling conditions.

Typical CO2 Levels

• Natural freshwater: 0.5-2 mg/L
• Aquaculture (safe): < 10-15 mg/L
• Aquaculture (stress level): > 20 mg/L
• Carbonated beverages: 3,000-4,000 mg/L
• Beer: 4,500-5,000 mg/L