SKU: SENS-0786
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Sensirion STC31-C-R3 CO2 Concentration Sensor 0-100% vol - I2C Output

₹4,239.00 (Inclusive of all taxes)
Out of Stock

The Sensirion STC31-C-R3 is a high-precision thermal conductivity CO₂ sensor module with a 0–100% vol measurement range, featuring a digital I2C interface for seamless integration with microcontrollers like Arduino, Raspberry Pi, ESP32, and industrial PLCs.

Features

  • Measures COâ‚‚ concentration from 0 to 100% by volume using thermal conductivity principle.
  • Digital I2C interface supports Standard, Fast, and Fast-Mode Plus communication.
  • Features dual measurement modes: low-noise and low-cross-sensitivity for optimized performance.
  • Supports Automatic Self-Calibration (ASC) and Forced Recalibration (FRC) for long-term accuracy.
  • Compact SMD package measuring 10.0 x 10.5 mm with a weight of only 0.025g.

Out of stock

Description

The STC31-C-R3 from Sensirion is a MEMS-based thermal conductivity sensor engineered for precise measurement of carbon dioxide concentrations across a full 0–100% volume range in air or nitrogen backgrounds. Its operation relies on the change in thermal conductivity of a gas mixture relative to its CO₂ content, providing a stable and direct reading without the need for optical components.

The module includes advanced on-chip signal conditioning and offers two selectable measurement modes to prioritize either low-noise operation or reduced cross-sensitivity to other gases. For maximum accuracy across varying conditions, the sensor algorithm compensates for environmental influences using externally supplied temperature, humidity, and pressure data. Each unit is individually factory calibrated and carries a unique serial number, ensuring traceability and consistent performance for critical medical, industrial, and environmental monitoring applications.

Key Features

  • High-precision thermal conductivity sensing principle for 0–100% vol COâ‚‚.
  • Digital I2C output with selectable addresses for easy daisy-chaining.
  • Dual operational modes: Low-Noise and Low-Cross-Sensitivity for application-specific optimization.
  • Integrated support for Automatic Self-Calibration (ASC) and Forced Recalibration (FRC) routines.
  • Requires external temperature, humidity, and pressure inputs for full environmental compensation.
  • Robust operating temperature range from -40°C to +105°C.
  • Ultra-compact surface-mount device (SMD) footprint for space-constrained designs.
  • REACH and RoHS compliant, featuring a high-value build for demanding environments.

Applications

  • Medical gas mixture analysis and ventilator COâ‚‚ monitoring.
  • Industrial process control and safety monitoring in fermentation, welding, or beverage carbonation.
  • Environmental and agricultural research in controlled atmosphere studies.
  • Building automation and HVAC system efficiency verification.
  • Laboratory instrument integration for gas analysis and calibration.

Technical Specifications

Manufacturer Part NumberSTC31-C-R3
Sensor TypeCOâ‚‚ Concentration Sensor (Thermal Conductivity)
Measurement Range0 – 100% by volume (vol%)
Output InterfaceDigital I2C (2-wire)
Supply Current3 – 5 mA (typical)
Operating Temperature-40 °C to +105 °C
Pressure Range200 – 2000 hPa (0.2 – 2.0 bar)
Resolution16-bit digital output
Accuracy±0.5 °C (for referenced temperature sensor, 10–50°C range)
Response Time< 0.5 seconds
Dimensions (L x W)10.0 mm x 10.5 mm
Weight0.025 g

Frequently Asked Questions

What is the operating principle of the STC31-C-R3 CO2 sensor?

The STC31-C-R3 utilizes a MEMS-based thermal conductivity sensing principle. It measures the change in thermal conductivity of a gas mixture, which correlates directly to the concentration of COâ‚‚, providing a stable and non-optical method for full-range 0-100% vol measurement.

How do I calibrate this sensor for long-term accuracy?

The sensor supports two calibration methods via its I2C commands: Automatic Self-Calibration (ASC), which uses periodic background references, and Forced Recalibration (FRC), which requires a known reference gas concentration. Implementing these routines is essential for maintaining specified accuracy over the sensor's lifetime.

What external data does the sensor require for accurate measurements?

For optimal accuracy, the sensor's algorithm requires compensated temperature, relative humidity, and absolute pressure data provided by the host system via the I2C interface. This environmental compensation is critical for precise readings across varying conditions.

Can I use this sensor with 5V microcontrollers like Arduino Uno?

Yes, but you must check the sensor's datasheet for its exact logic level voltage tolerance. The I2C interface typically operates at 3.3V. If your microcontroller uses 5V logic, a level shifter or a careful review of the absolute maximum ratings is required to ensure safe communication.

Package Includes

  • 1 x Sensirion STC31-C-R3 CO2 Concentration Sensor Module

Additional Information

Weight 0.000025 kg
Dimensions 1 × 1.05 cm