CO2 Probe | Dissolved Carbon Dioxide Sensor in Water | Frankstar,
agricultural storage CO2 monitor, aquaculture CO2 monitoring, dissolved gas sensor, HVAC CO2 monitoring sensor, industrial CO2 sensor, Modbus CO2 probe, NDIR carbon dioxide probe, oceanography carbon dioxide probe, pCO2 sensor water, RS485 dissolved CO2 sensor, submersible CO2 probe, UART I2C CO2 sensor, water carbon dioxide measurement,

Feature

Small size, light weight
2.8 million sets of measurements
Configurable sampling period

USB Data Download

Pressure calibration before water entry

Technical Parameter

Housing material: POM
Housing pressure: 350m
Power: 3.6V or 3.9V disposable lithium battery
Communication mode: USB
Storage space: 32M or 2.8 million sets of measurements
Sampling frequency: 1Hz/2Hz/4Hz
Sampling period: 1s-24h.

Clock drift: 10s / year

Pressure range：20m、50m、100m、200m、300m
Pressure accuracy：0.05%FS
Pressure resolution：0.001%FS

Temperature range：-5-40℃
Temperature accuracy：0.01℃
Temperature resolution：0.001℃

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## Precision Dissolved CO₂ Monitoring for Critical Water Applications

Accurate measurement of dissolved carbon dioxide is essential across a growing range of industries, from aquaculture and HVAC performance to environmental research and controlled-atmosphere storage. Frankstar’s CO₂ Probe offers a robust, NDIR-based solution engineered to deliver consistent data in both laboratory and field-deployed settings. The sensor combines advanced infrared absorption technology with practical mechanical design, ensuring reliable long-term performance with minimal maintenance requirements.

## NDIR Technology with Dual-Channel Reference Compensation

At the heart of the Frankstar CO₂ Probe lies a non-dispersive infrared (NDIR) absorption measurement cell. The sensor employs a proprietary patented optical cavity design that enhances signal stability while minimizing drift over time. Unlike simpler single-channel sensors, this unit incorporates dual-channel reference compensation, which continuously corrects for light source aging, humidity effects, and temperature variations. This architecture provides an accuracy of ±5% full scale, giving operators confidence in data collected across extended deployment periods or in environments with fluctuating ambient conditions.

The NDIR method is inherently selective for carbon dioxide, avoiding cross-sensitivity issues that can affect electrochemical or wet-chemical measurement approaches. Because the sensor measures CO₂ gas that equilibrates across a semi-permeable membrane, it effectively reports the dissolved carbon dioxide concentration in the surrounding water.

## Built for Real-World Field Deployment

Field servicing is a practical reality for any dissolved gas sensor, and Frankstar has addressed this directly in the CO₂ Probe’s mechanical design. The sensor features a detachable waterproof structure that allows technicians to access internal components without specialized tools or lengthy downtime. This modularity reduces the total cost of ownership and makes the probe suitable for remote installations where servicing windows are limited.

Gas exchange efficiency is a critical factor in dissolved gas sensor response time. The CO₂ Probe utilizes a convection diffusion ventilation design that accelerates the movement of CO₂ molecules from the water phase to the internal measurement cavity. This design simultaneously protects the gas-permeable membrane from physical damage and biofouling, striking a balance between fast response and long-term durability. The membrane itself is field-replaceable, further extending the sensor’s operational life.

## Flexible Integration Through Multiple Output Options

System integrators and automation engineers require sensors that communicate seamlessly with existing control infrastructure. The Frankstar CO₂ Probe supports this need with an extensive set of output modes:

- **UART (TTL level)** for direct microcontroller interfacing
- **I2C** for multi-sensor bus topologies
- **Analog voltage output** for legacy data loggers and PLCs
- **PWM output** for simple duty-cycle-based readouts

For industrial automation environments, the sensor supports the Modbus-RTU protocol over an RS485 physical layer. This enables straightforward integration with SCADA systems, building management platforms, and aquaculture control panels. The availability of multiple communication standards means the same sensor model can serve both benchtop research setups and large-scale industrial deployments without additional signal conditioning hardware.

## Key Applications

### Aquaculture and Recirculating Aquaculture Systems (RAS)
Dissolved carbon dioxide accumulates rapidly in intensive fish and shrimp farming systems, particularly in RAS where water reuse concentrates metabolic byproducts. Elevated CO₂ levels can suppress respiration in cultured species and reduce growth rates. The Frankstar CO₂ Probe provides continuous, real-time monitoring that allows operators to adjust aeration, degassing, and water exchange rates before harmful thresholds are reached.

### HVAC and Indoor Air Quality
In large commercial buildings, dissolved CO₂ sensors installed in chilled water loops or condensation systems serve as an indirect but effective indicator of overall system performance and air handling. The probe’s Modbus capability enables direct integration with building automation controllers, contributing to demand-controlled ventilation strategies and energy optimization programs.

### Agricultural Storage and Controlled-Atmosphere Environments
Fruit and vegetable storage facilities rely on precise CO₂ management to delay ripening and extend shelf life. The CO₂ Probe can be deployed in humid storage environments to monitor headspace gas composition via equilibrated water samples or condensate loops, offering a maintenance-friendly alternative to direct gas-phase sensors in high-moisture zones.

### Environmental Monitoring and Coastal Oceanography
Researchers studying ocean acidification, estuarine carbon cycles, or freshwater ecosystem metabolism require reliable dissolved CO₂ data. The probe’s NDIR measurement principle and dual-channel compensation make it suitable for extended deployments on moorings, buoys, and profiling systems, where recalibration opportunities are infrequent.

## Dependable Performance Without Complexity

The Frankstar CO₂ Probe is designed to reduce the friction between needing a measurement and obtaining it. Temperature compensation is handled internally within the sensor firmware, eliminating the need for external correction tables. The compact form factor and standard mounting options allow the probe to be installed in flow-through cells, submersion pipes, or open-water cages with equal ease.

Because the sensor uses physical infrared absorption rather than chemical reagents, there are no consumables to replenish beyond periodic membrane replacement. This translates to predictable operating costs and fewer interruptions in data continuity—a critical consideration for long-term monitoring programs and production facilities that operate around the clock.

## Why Choose Frankstar for Dissolved Gas Sensing

Frankstar Technology focuses on delivering oceanographic and environmental monitoring instrumentation that combines measurement integrity with practical field maintainability. The CO₂ Probe reflects this philosophy: a sensor that meets the accuracy expectations of research scientists while remaining accessible to aquaculture technicians and facilities engineers. The availability of factory calibration, multiple output protocols, and a modular mechanical design means one sensor platform can address a wide range of dissolved CO₂ monitoring requirements without custom engineering.

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**Interested in integrating the CO₂ Probe into your monitoring system or research project?** Contact Frankstar Technology to discuss your application requirements, request technical specifications, or inquire about OEM and distributor opportunities. Our team supports customers worldwide with pre-sales configuration, integration guidance, and long-term service planning.