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This product is no longer available

We no longer stock CO₂ Sensor - STC31 (Qwiic), but here are current alternatives in Gas & Air Quality Sensors.

CO₂ Sensor - STC31 (Qwiic)

CO₂ Sensor - STC31 (Qwiic)

Discontinued

The STC31 CO₂ Sensor Breakout measures carbon dioxide concentrations from 0 to 100 vol% using Sensirion's thermal conductivity sensing technology. The board also includes a separate SHTC3 humidity and temperature sensor for humidity-compensated CO₂ measurements and improved temperature compensation. Communication is via I²C with Qwiic connectors for solderless hookup.

The STC31 is calibrated for CO₂ in nitrogen and CO₂ in air, with configurable I²C address selection via split-pad jumpers on the back of the board. The power LED and I²C pull-ups can be disabled by cutting the corresponding jumpers.

Key Features

  • Sensirion STC31 – Thermal conductivity CO₂ sensor with 16-bit resolution
  • Two Measurement Ranges – 0–25 vol% and 0–100 vol%
  • Measurement Accuracy – 0.5 vol% + 3% (0–25%); 1 vol% + 3% (0–100%)
  • Repeatability – 0.2 vol%
  • Stability – 0.025 vol% / °C
  • SHTC3 Humidity/Temperature Sensor – ±2% RH and ±0.2 °C for compensation
  • Atmospheric Pressure Compensation – Software-configurable
  • Qwiic I²C Interface – Dual connectors, configurable address (0x29, 0x2A, 0x2B, 0x2C)

Specifications

  • STC31 Supply Voltage – 2.7–5.5 V (Qwiic bus operates at 3.3 V)
  • SHTC3 Supply Voltage – 1.62–3.6 V
  • STC31 Temperature Range – −20 °C to +85 °C
  • SHTC3 Temperature Range – −40 °C to +125 °C
  • SHTC3 Humidity Range – 0–100% RH
  • SHTC3 I²C Address – 0x70 (non-configurable)
  • Start-Up Time – 14 ms

Ideal For

  • High-concentration CO₂ monitoring (fermentation, industrial processes)
  • Gas mixing and blending applications
  • Environmental and safety monitoring
  • Laboratory and research instrumentation

Package Contents

  • 1× CO₂ Sensor Breakout (STC31 + SHTC3, Qwiic)

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