SCD41

SCD41 is a compact digital CO2 sensor from Sensirion. It measures CO2 concentration (ppm) and includes built‑in temperature and relative humidity sensors to properly compensate CO2 readings. It communicates over I2C or SPI and is designed for low power operation, making it suitable for battery-powered devices.
Key points:
- Small form factor and easy integration
- Low power with fast response
- Automatic Baseline Calibration (ABC) to track outdoor CO2 levels
- Factory-calibrated with option for user calibration
- Provides CO2, temperature, and humidity data digitally
Typical use cases:
- Indoor air quality monitoring
- HVAC and building automation
- Demand-controlled ventilation
- Smart home and portable devices
In short, SCD41 delivers accurate, low‑power CO2 sensing with temperature and humidity compensation in a ready-to-use digital package.

Equivalent products to the Sensirion SCD41 (miniature NDIR CO2 sensor):
- Sensirion SCD30, SCD40 (same family)
- Senseair modules (S8, Sunrise, K30)
- Cubic/COZIR CO2 modules (COZIR series)
- Winsen MH‑Z19 / MH‑Z19B
- Amphenol/Telaire modules (T6615, T6713)
Compare size, accuracy, power, interfaces and calibration requirements before substituting.

Here are the key features of the Sensirion SCD41 CO2 sensor:
- CO2 measurement: 400–5,000 ppm with high accuracy (NDIR core) for indoor air quality.
- Temperature compensation: built-in temperature sensor used to correct CO2 readings.
- Interface: digital I2C interface; supports multiple devices on the same bus; operates from common logic voltages.
- Power and modes: low-power operation with selectable measurement modes and sleep/wake options.
- Calibration: Automatic Baseline Calibration (ABC) for long-term drift correction; options for forced calibration.
- Size and robustness: compact surface-mount LGA package suitable for compact sensors and devices.
- Response and update: fast CO2 response with configurable measurement cycle (typ. around 1 Hz, configurable).
- Humidity: does not measure humidity itself; if RH data is required, pair with a separate Sensirion humidity sensor (e.g., SHT series).
Note: Specific electrical ranges, currents, and accuracy may vary by revision; consult the latest datasheet for exact numbers.

SCD41 pin count: 6 pins (LGA/DFN-6).
Pin functions (I2C interface):
- VDD: supply power
- GND: ground
- SCL: I2C clock
- SDA: I2C data
- ADDR: I2C address select
- ALERT/RESET: interrupt/alert output or reset input (used for status/data ready)

The SCD41 is manufactured by Sensirion AG. Sensirion is a Swiss high‑technology company that designs and manufactures MEMS‑based environmental and flow sensors—specializing in digital gas (CO₂), humidity, temperature, and flow sensor solutions for consumer, HVAC, automotive, medical, and industrial markets.

SCD41 is used for CO2, temperature, and humidity sensing. Key applications include:
- Building automation and HVAC: demand-controlled ventilation, energy optimization
- Indoor air quality monitoring: offices, schools, hospitals, commercial spaces
- Smart home and consumer devices: air-quality meters, purifiers, thermostats
- Industrial and controlled environments: labs, data centers, cleanrooms
- IoT / smart city sensing: IAQ sensor networks and environmental monitoring nodes
Note: follows compact, low-power, digital (I2C) CO2 + temp/humidity sensing.

SCD41 uses a land-grid array (LGA) package.