Three inexpensive CO2 sensors compared

Sniffing the Air

© Lead Image © vladnikon, 123RF.com

© Lead Image © vladnikon, 123RF.com

Article from Issue 294/2025
Author(s):

Monitor your indoor air quality with an inexpensive CO2 sensor. We look at three candidates to help you find the best solution.

In the winter, you spend a lot of time indoors, making it important to keep an eye on CO2 concentrations. In contrast to sensors for measuring temperature and humidity, CO2 sensors are quite expensive, with prices consistently in the double-digit range. This quickly adds up if you want to monitor more than one room. To make CO2 monitoring more budget friendly, this article focuses on three inexpensive solutions: the Winsen MH-Z19C [1], the ScioSense ENS160 [2], and the Sensirion SCD40 [3].

The latter sensor from brand manufacturers such as Adafruit, Pimoroni, or SparkFun are really expensive, costing between $40 and $80. AliExpress gives you cheaper options with prices below $15, but those come with the added thrill of not knowing whether parts will even work.

Infrared Measurement

The Winsen MH-Z19C (Figure 1) consists of a small box measuring approximately 13.3mm x 26mm x 4.4mm. It measures the CO2 value using the non-dispersive infrared method (NDIR). Two versions of the sensor are available: one with a normal pinout and one with a cable connection and a pin spacing of 1.25mm. If you don't relish the prospect of crimping connections, you will want to opt for the pinout version. Besides the MH-Z19C, there are other older models on the market, such as the MH-Z19B, MH-Z14, or MH-Z18, which have similar but not identical functions and specifications.

[...]

Use Express-Checkout link below to read the full article (PDF).

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
 
SUBSCRIPTIONS
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • Sensor Shootout

    Any application that collects a large number of measurements is bound to have some anomalous measurements, but good sensor breakouts should not output such values all the time. We tested eight temperature and humidity sensors for accuracy.

  • DIY Pulse Sensor

    A pulsemeter built with a Raspberry Pi, a digital-to-analog converter, and an optical sensor monitors your heart rate just as well as many far more expensive medical devices.

  • WiFi Thermo-Hygrometer

    A WiFi sensor monitors indoor humidity and temperature and a Node-RED dashboard reports the results, helping you to maintain a pleasant environment.

  • Bluetooth Positioning

    The GPS tracking service isn't precise enough to provide positioning information within a home. Home automation expert Gunnar Beutner decided to harness the invisible spirits of Bluetooth for a home-grown indoor positioning system.

  • Automated Irrigation

    An automated watering system comprising a Raspberry Pi Zero W, an analog-to-digital converter, and an inexpensive irrigation kit can help keep your potted plants from dying of thirst.

comments powered by Disqus
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters

Support Our Work

Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

Learn More

News