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SCD40 SCD41 True CO2 Sensor

Please note, each sensor is tested before dispatch. Each sensor has a unique serial number which is recorded on the invoice.

The SCD40/41 from Sensirion are a high quality Photoacoustic based CO₂ sensors.

The sensors are 'true' CO₂ sensors that will tell you the CO₂ PPM (parts-per-million) composition of ambient air.

Unlike other sensors, these sensors are not approximating from VOC gas concentration - it really is measuring the CO2 concentration!

In order to improve accuracy the SCD40/41 have integrated temperature and humidity sensing built-in.

Please note: The SCD40 & SCD41 have has an automatic self-calibration routine.

Sensirion recommends 7 days of continuous readings with at least 1 hour a day of 'fresh air' for self-calibration to complete.

There are two variants of this sensor - the SCD-40 and SCD-41.

The SCD-40 is lower cost, and is perfect for indoor/outdoor air quality and CO2 measurements.

It has a range of 400-2,000 ppm with an accuracy of ±(50 ppm + 5% of reading).

The SCD-41 is more expensive, and while it can definitely be used for air quality, it's wide range means its best used for industrial or scientific CO2 measurements where the ppm can get very high.

It has a range of 400-5,000 ppm with an accuracy of ±(40 ppm + 5% of reading)

The sensors can run from 2.4 to 5V but it's more important for it to have a quiet power supply with low ripple, than any particular voltage.

When connecting to a 5V microcontroller like an Arduino UNO the 5V supply is often shared with other electronic components that add noise.

So if your board has 3.3V, connect to that instead.

Resources:

Datasheet - https://sensirion.com/media/documents/C4B87CE6/627C2DCD/CD_DS_SCD40_SCD41_Datasheet_D1.pdf

Sensirion SCD4x CO₂ sensors product guide - https://developer.sensirion.com/sensirion-products/scd4x-co2-sensors/

Arduino drivers & tutorial :

https://github.com/Sensirion/arduino-i2c-scd4x/blob/master/README.md

SDCD4x	UNO/Nano	MEGA2560	Leonardo Pro Micro
GND	GND	GND	GND
Vcc	3.3V/5V	3.3V/5V	3.3V/5V
SCL	A5	21	3
SDA	A4	20	2

(3.3V recommended. Baud rate set to 115200)

https://learn.adafruit.com/adafruit-scd-40-and-scd-41/arduino

Raspberry drivers & tutorial :

https://github.com/Sensirion/raspberry-pi-i2c-scd4x/blob/master/README.md

https://learn.adafruit.com/adafruit-scd-40-and-scd-41/python-circuitpython

SCD4x Specifications:

Photoacoustic CO2 sensor technology

Integrated temperature and humidity sensor

Fully calibrated and linearized

I2C digital interface address 0x62

Measurement range : SCD40 400ppm – 2,000ppm / SCD41 400ppm – 5,000ppm

Accuracy : ±(50 ppm + 5 % of reading)

Vdd range : 2.4 to 5.5V

Current consumption : 17 mA (meas. rate = 5 s) / 0.5 mA (meas. rate = 5 min)

Sensor Element Size : ~10.1 x 10.1 x 6.5mm

Product Dimensions : ~21.6 x 13.4 x 7.7mm

Package includes:

1x SCD40 or SCD41 Sensor module as selected

Pin set

1x 4-wire DuPont cable (Please specify either Male to Female, Female to Female or Male to Male: subject to stock. May consist of one or sections).

Important Note:

Our goal is to achieve 5-star rating for each transaction.

If you are not 100% satisfied, PLEASE do not leave a neutral or negative feedback but contact us by eBay message or email first so that we can help you.

Postage

All of our products are stocked at our London premises therefore there are no delays in posting.

We will dispatch all orders the same day if the order has been placed before 3:00pm Monday - Friday (excluding public holidays).

All orders are processed by third party dispatching software and therefore eBay's confirmation dispatch email may be delayed.

Orders dispatched via Royal Mail may be upgraded to Signed-For or Tracked service at our discretion.

Average delivery times for Royal Mail are 1-3 days for 1st/24 and 3-5 days for 2nd/48.

Only Royal Mail's Special Delivery service is guaranteed next working day (Mon-Fri) service.

Most items which are not received are caused by incomplete addresses such as no door number, or incorrect street name or postcode.

Payment

Payment is via eBay's checkout facility.

Once payment has been same, requests for change of delivery address will not be accepted due to eBay's Buyer Protection Scheme.

Orders must be cancelled and reordered with the correct delivery address.

Warranty

If you have simply changed your mind or no longer require the item(s), you must notify us within 30 days from receiving your order.

The item(s) must be in their original unused and unopened packaging and be in a resalable condition for a full refund.

You will need to pay for the cost of returning the item(s) and the item(s) remain your responsibility until we receive them.

Damaged caused during transit must be notified within two days of the delivery.

All items sold as tested are genuinely tested before dispatch.

Product(s) which show obvious signs of misuse, damage or weather damage will not be eligible for refund or replacement.

All items are security marked.

Please ensure all security markings and stickers are intact or any warranty offered will be void.

All items are subject to satisfactory inspection of the anti-tamper warranty sticker/seal.

Any evidence that these aforementioned stickers/seals have been removed or broken will render the item out of warranty and will not be covered under warranty rules.

If the item becomes faulty within that period a replacement will be issued free of charge upon receipt of the faulty item, back to us, if proved to be faulty upon inspection.

If the item is not faulty or can be repaired, not to the detriment of the item, then this shall be undertaken rather than direct replacement.

Warranty Exclusion: Please note that as batteries are "consumables" we only provide dead on arrival warranty.

The maximum capacity of all rechargeable batteries fades with time depending on application and usage patterns.

This is considered normal - therefore, a change in battery capacity is not covered under warranty.

Battery life is not warranted and will vary depending on usage.

Please note- Any software is not covered by the warranty policy. Please refer to the copyright owner for specific details.