Article: Monitoring Carbon Dioxide in your classroom

As well as being implicated in global warming and generic pollution Carbon dioxide is an important gas for the regulation of breathing. It's and odd piece of physiology that considering our dependence upon oxygen for life we have no real oxygen detection mechanism in our body. Instead we use indirect carbon dioxide measurement to work out if we are getting enough oxygen.

In terms of the respiration biochemistry, for each molecule of oxygen used, a molecule of carbon dioxide is produced. You only have to measure carbon dioxide to get a measure of oxygen requirements. If Carbon dioxide is rising then you are using more oxygen and vice versa.

Excess carbon dioxide is normally a measure of increase activity, increased activity tires us. Simplistically stated excess carbon dioxide will create feelings of tiredness and malaise.

In a closed environment a build up of carbon dioxide in the environment creates an increase in carbon dioxide within us, it also is an indicator of poor air circulation. You should not get an increase in carbon dioxide if air is free moving.

There has been evidence recently that suggests that a form of sick building syndrome is down to poor ventilation. A measurement of carbon dioxide can be used as a simple model of poor ventilation - in a well ventilated space there should not be a build up of carbon dioxide.

While it is known that carbon dioxide will create a bad atmosphere, most sensor technology centres around carbon monoxide. Carbon monoxide is deadly, it is not a natural environment gas and we have not evolved the ability to detect it, hence it is known as the silent killer.

Carbon dioxide is a natural environment gas and we can detect changes and react to them. The level of carbon dioxide is very low in the atmosphere but that does not tell us the truth about how it reacts and the damage it can do. The low value of carbon dioxide in the air and the small differences that create change means we measure it in a very low level unit ppm (parts per million). 1 ppm is equal to 0.0001%. Until recently atmospheric carbon dioxide levels were at 300pp or 0.003%.

How to monitor Carbon Dioxide in your classroom with the Smart Wireless Carbon Dioxide Sensor?

The data Harvest Carbon Dioxide sensor can measure over the range 0 to 100,000 with a 1ppm resolution. The sensor can also measure temperature, humidity and pressure at the same time. It is an ideal sensor for monitoring the room atmosphere.

The wireless connectivity to any device (android, iOS, chrome) also means you can quickly link to the sensor and take “spot” readings. 

We have conducted our own practical over the course of a working day to investigate how carbon dioxide levels change dynamically, it also (in our case) showed how stubborn they were to change. Even full window opening and forced ventilation by fans only halved the recorded levels.

Download our free worksheet here and use the Smart Wireless Carbon Dioxide Sensor with the following possible activities.

1. The daily pattern of carbon dioxide measure over a single day.
2. The effect of a classroom full of Bunsen burners being used.
3. The impact (or not) of working with windows open (does the drop in CO2 justify the need to wear balaclavas!!
4. Comparison of different rooms.
5. How quickly does a room return to background?
6. In all cases we are assuming that high carbon dioxide is a sign of poor ventilation.

Background Information: https://www.gov.uk/government/news/all-schools-to-receive-carbon-dioxide-monitors