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SCD40

Compact & cost-effective photoacoustic NDIR CO₂ sensor

The SCD40 represents the base variant in the SCD4x series and provides a cost-effective photoacoustic NDIR CO2 sensor delivering an accuracy of ±(50ppm + 5% m.v.) between 400 and 2000 ppm. The sensor is compatible with the WELL Building Standard™.

 

The SCD4x is Sensirion’s second generation series of optical CO2 sensors. The sensor series builds on the photoacoustic NDIR sensing principle and Sensirion’s patented PASens® and CMOSens® technology to offer accuracy at an attractive price and small form factor. SMD assembly allows cost- and space-effective integration of the sensor combined with maximal freedom of design. On-chip signal compensation is realized with the built-in SHT4x humidity and temperature sensor. Tape and reel packaging make the SCD4x ideal for high-volume applications.

 

Carbon dioxide is a key indicator for indoor air quality (IAQ), as high levels compromise human cognitive performance and well-being. The SCD4x enables smart ventilation regulation to help improve energy efficiency and human comfort. Moreover, indoor air quality monitors and other connected devices based on the SCD4x can help maintain low CO2 concentrations for a healthy, productive environment.

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Specification

CO₂
CO₂ Output Range
0 - 40000
0 - 40000ppm
Specified CO₂ Measurement Range
400 - 2000
400 - 2000ppm
Accuracy
±50.0 ppm ±5.0 %m.v.
±50.0 ppm ±5.0 %m.v.
Response time (τ63%)
60
60s
Humidity
Typ. relative humidity accuracy
6
6%RH
Operating relative humidity range
0 - 95
0 - 95%RH
Response time (τ63%)
90
90s
Calibration certificate
Factory calibration
Factory calibration
Generic
Supply voltage
2.4 - 5.5
2.4 - 5.5V
Average supply current
15
15mA
Max. supply current
205
205mA
Operating temperature range [°C]
-10 - 60
-10 - 60°C
Interfaces
I²C
I²C
Size (LxWxH)
10.1 x 10.1 x 6.5
10.1 x 10.1 x 6.5mm
Packaging size
60 and 600
60 and 600pcs (T&R)
Temperature
Typ. temperature accuracy
0.8
0.8°C
Response time (τ63%)
120
120s

Downloads

Datasheet SCD4x

04/2025

File

1.2 MB

Datasheet04/2025PDF1.2 MB
Low power operation SCD4x

07/2022

File

443.0 KB

Application note07/2022PDF443.0 KB
Design-in guide SCD4x

01/2021

File

478.2 KB

Guide01/2021PDF478.2 KB
Handling instructions SCD4x

02/2025

File

360.3 KB

Guide02/2025PDF360.3 KB
Testing guide SCD4x

File

2.0 MB

GuidePDF2.0 MB
Arduino driver SCD4x

Link

SoftwareLink
Arduino snippets SCD4x

Link

SoftwareLink
BLE gadget SCD4x

Link

SoftwareLink
Embedded driver SCD4x

Link

SoftwareLink
Makecode for micro:bit SCD4x

Link

SoftwareLink
Python driver SCD4x

Link

SoftwareLink
Raspberry Pi driver SCD4x

Link

SoftwareLink
SEK-ControlCenter (all devices)

Link

SoftwareLink
Altium footprint SCD4x

Link

Drawings/CADLink
STEP file SCD4x

File

632.1 KB

Drawings/CADSTEP632.1 KB
STEP file SEK-SCD41

File

770.9 KB

Drawings/CADSTEP770.9 KB
Calibration certification SCD4x

05/2022

File

118.0 KB

Certificate05/2022PDF118.0 KB
Carbon Dioxide product flyer

07/2025

File

881.9 KB

Flyer07/2025PDF881.9 KB
Carbon Dioxide product flyer Chinese

07/2025

File

960.9 KB

Flyer07/2025PDF960.9 KB
What types of NDIR sensors exist and how do they work?

05/2022

File

146.5 KB

Application note05/2022PDF146.5 KB
What types of NDIR sensors exist and how do they work? (Japanese)

10/2023

File

277.2 KB

Application note10/2023PDF277.2 KB
REACH and RoHS declaration SCDxx

03/2025

File

85.0 KB

Certificate03/2025PDF85.0 KB
Carbon dioxide product flyer Japanese

07/2025

File

1.2 MB

Flyer07/2025PDF1.2 MB
Indoor air quality brochure

11/2024

Link

7.7 MB

Flyer11/2024Link7.7 MB
  • SCD40

SCD40

SCD40-D-R2

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Sensor evaluation

Buy the following products to evaluate this sensor

NameDescriptionSeriesCategory
SEK-SCD41Evaluation kit for SCD4x series CO2 sensorsSEK-SCDxxCO₂
SEK-SensorBridgeConnecting bridge with two sensor portsSEK-SensorBridge

SEK-SCD41

Evaluation kit for SCD4x series CO2 sensors

SEK-SCDxx

CO₂

SEK-SensorBridge

Connecting bridge with two sensor ports

SEK-SensorBridge

Download the respective viewer software to start measuring

Go to download center

Start testing our sensors fast and easy with the evaluation kits

How to get started

Smart sensors for your application

Sensirion's sensor solutions are used in a wide range of applications and markets. Our reliable environmental and flow sensors improve energy efficiency, increase health and ensure safety and comfort.

Global Distributors

Part numberQuantityDistributor nameCountryUploaded
SCD40-D-R28068DigiKeyUS, DE, HK17.07.2025Buy
SCD40-D-R2772Mouser Electronics Inc.27 countries18.07.2025Buy

EMEA (Europe)

Part numberQuantityDistributor nameCountryUploaded
SCD40-D-R2266SOS electronic s.r.o.PL, HU, CZ, DE, SK17.07.2025Buy

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