The post on CO2 dual thermal sensors identifies different options for Mid-InfraRed (MIR) spectral sensing of air content of CO2 and CH4. This post instead summarises a Mid Infraa-Red (MIR) “plug-and-play”Nondispersive infrared (NDIR) gas detector for CO2.
Introduction
NDIR gas detection relies on an emitter and a sensor placed opposite each other inside a dark chamber. The Winsen MH-Z16 Infrared CO2 Gas Sensor is built with a 10 cm long cylindrical chamber with a microcontroller on top. It runs on 5 Volt and 80 mA and can be attached to an Arduino microcontroller.
MH-Z16 Infrared CO2 Gas Sensor
Gyawali et al, 2019 used the MH-Z16 sensor for developing an arduino based soil microbial activity assessment contraption (SMAAC). Or, stated more directly, a dual band MIR sensor that can be used for estimating soil CO2 content and thus soil respiration.
Gyawali et al, 2019 compared the SMAAC with a commercial infra-red gas analyzer (IRGA) and found that the SMAAC performed well as an inexpensive yet accurate tool for measuring soil respiration and microbial activity.
Specification
Specification
- Gas Detection: Carbon Dioxide (CO2)
- Operating Voltage: 4.5 ~ 5.5V DC
- Average Current: <85mA
- Output Signal: UART
- Measuring Range: 0 ~ 50000ppm
- Accuracy: ± (50ppm + 5% reading)
- Preheating Time: 3min
- Response Time: T90 < 30s
- Operating Temperature: 0 ~ 50 ℃
- Operating Humidity: 0 ~ 95% RH (no condensation)
- Weight: 42 g
The Winsen MH-Z16 Infrared CO2 Gas Sensor is sold by many vendors. DR-robot sell their own version under their Gravity series at 90 USD. Also Seeed-studio sell their own version - under their Grove series. It costs 98 USD.
Developing the SMAAC, Gyawali et al, 2019 used an [MH-Z16 from Sandbox](https://sandboxelectronics.com/?product_tag=co2-sensor](https://sandboxelectronics.com/?product_tag=co2-sensor).
The Chinese company Winsen produces the MH-Z16 CO2 sensor, which is identicial to the above (probably it is the same). Buying this sensors in larger quantities at AliExpress you can get the [Winsen plug-and-play CO2 at 35 USD] (https://www.aliexpress.com/item/1005004678211790.html?spm=a2g0o.productlist.0.0.685d105dVZn6wH&algo_pvid=c125256c-1627-4826-8d7a-f46ac4d6aa62&algo_exp_id=c125256c-1627-4826-8d7a-f46ac4d6aa62-16&pdp_ext_f=%7B%22sku_id%22%3A%2212000030070843054%22%7D&pdp_npi=2%40dis%21USD%21487.5%21360.75%21%21%21%21%21%402100bddf16676764667453237ec9c4%2112000030070843054%21sea&curPageLogUid=pv3FzfznqwwV).
I bought my copies of the MH-Z16 sensor from Aliexpress where you can get one (1) for as little as 35 USD if you buy several in one go.
Seeedstudio also offers a smaller CO2 NDIR at 600 SEK.
Sketch
Example code for integrating this sensor with the Arduino is available at https://github.com/SandboxElectronics/NDIRZ16.
Seeed-studio provides setup instructons including an Arduino sketch. But the code does not operate properly. A corrected code is offered by devmobilenz. For details see the project post.
Component Project Nano