Introduction
CO2 is a key factor for indoor air quality as high levels compromise human cognitive performance and well-being.
This Gravity: SCD41 CO2 sensor is based on the SCD41 miniature CO2 sensor from Sensirion. SCD41 builds on the photoacoustic NDIR sensing principle and Sensirions patented PAsens and CMOSens technology to offer high accuracy at an unmatched price and the smallest form factor. On-chip signal compensation is realized with the built-in temperature and humidity sensor, while temperature and humidity data outputs are also available.
SCD41 sensor detects the amount of energy that is absorbed by CO2 molecules. When pulsing the infrared emitter, CO2 molecules absorb infrared light periodically. This causes additional molecular vibration resulting in a pressure wave inside the measurement chamber. The higher the CO2 concentration, the more light is absorbed, and thus the greater the amplitude of this acoustic wave becomes. A microphone inside the gas chamber measures this, from which the CO2 concentration can then be calculated.
Click to learn more about PAsens technology.
Click to learn more about NDIR sensors.
| Gravity CO2 Sensor Selection Guide |
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| Product Name |
Gravity: Analog Electrochemistry CO2 Sensor |
Gravity: Analog IR CO2 Sensor |
Gravity: UART IR CO2 Sensor |
Gravity: I2C SCD41 Infrared CO2 Sensor (400 – 5000 ppm) |
| SKU |
SEN0159 |
SEN0219 |
SEN0220 |
SEN0536 |
| Operation Voltage |
3.75V |
4.55.5V |
4.55.5V |
3.3V-5V |
| Output |
Gravity: Analog (Analog2.74.1V) + 3P Header Digital Output(Alarm):0VCC Level |
Gravity: Analog (Analog Output 0.42V) |
Gravity: UART (03.3V Level) |
Gravity: I2C |
| Measurement Principle |
Electrochemistry Solid electrolyte battery principle |
NDIR(non-dispersive infrared) |
NDIR(non-dispersive infrared) |
photoacoustic NDIR |
| Measurement Range |
010000 ppm |
05000 ppm |
050000 ppm |
4005000ppm |
| Accuracy |
100ppm@400ppm |
(100ppm + 6% readings) |
(100ppm + 6% readings) |
(40 ppm + 5% MV) |
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Response
Time
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<20s |
<90s |
<30s |
60S |
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Average
Power
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<1W |
<430mW@5V |
<430mW@5V |
<30mW@5V |
| Operation Temperature |
-2050 |
050 |
050 |
-1060 |
| Operation Humidity |
095% RH (No condensation) |
095% RH (No condensation) |
095% RH (No condensation) |
095% RH (No condensation) |
| Lifespan |
>1 year |
>5 years |
>5 years |
>10 years |
Dimension (PCB) |
32*42 mm |
37*69 mm |
21*27.1 mm |
32*27*8mm |
| Features |
1. Large Range 2. Adjustable Alarm Threshold 3. Fast Response 4. Analog Output |
1. High Accuracy 2. Long Lifespan 3. Auto Temperature Compensation 4. Water Vapor Interference Resistance 5. Ananglog Output |
1. High Accuracy 2. Large Range 3. Long Lifespan 4. Auto Temperature Compensation 5. Water Vapor Interference Resistance 6.3.3V UART Output |
1.CO2, temperature, and humidity, three in one 2. Small size of 32*27*8mm 3. Low power, average current4mA |
Features
CO2, temperature, and humidity, three in one
Small size of 32*27*8mm
Low power, average current4mA
Specification
Power Supply: 3.3V to 5V
Average Operating Current: 4mA
I2C Address: 0x62
Product Size: 32*27*8mm/1.261.060.31″
CO2
Accuracy: (40 ppm + 5% MV)
Measuring Range: 400 – 5000 ppm
Response Time: 60s
Humidity
Typical Relative Humidity Accuracy: 6%RH
Relative Humidity Measuring Range: 0 to 95%RH
Response Time: 120s
Temperature
Typical Temperature Accuracy: 0.8
Temperature Measuring Range: -10 to 60
Response Time: 120s
Shipping List
Gravity: SCD41 Infrared CO2 Sensor x1
Gravity-4P I2C/UART Sensor Cable x1
Documents
Product wiki
Schematics
Dimensions
Design-in guide
Applications
Indoor CO2 concentration monitoring
Ambient monitoring in greenhouse
Smart ventilation systems