What they look like

The Sensor is intended only for measuring gases - not the concentration of CO2 in a liquid.

How the sensor works

The sensor uses a beam of infrared light, which is reflected around a highly polished cavity. Carbon dioxide is a strong absorber of infrared, the more the light is absorbed the greater the concentration of carbon dioxide present.

Practical Information

The Carbon Dioxide Sensor is best suited to measuring periods longer than 5 minutes.

Do not allow the sensing element to get wet at any time. If the Sensor is to be used in an environment where there is a risk of condensation e.g. with a plant in a sealed environment (plastic bag), position the Sensor so that any liquid that does condense will not come into contact with the sensing element.

Allow a few minutes for the Sensor to adjust to a new environment before recording data. Avoid disturbing the Sensor during an experiment as sudden air movement, or CO2 from breathing, can influence the results. Typical operating temperature range is from 20 to 40C.

CO2 is a gas that is heavier than air so it will therefore tend to sink to the bottom of the container, so there should be no need to make the container holding the sensor airtight.

Where it can be used

• Monitoring CO2 levels in small animals (e.g. maggots) at different temperatures
• Monitoring CO2 levels from plant material
• Air quality - monitoring CO2 with people in an enclosed space and the effects of room ventilation (opening a window)
• Cellular respiration of germinating seeds e.g. peas or beans
• The rate at which CO2 is removed from an enclosed atmosphere using sodium hydroxide or potassium hydroxide
• Rate of CO2 production in a chemical reaction e.g. between hydrochloric acid and sodium bicarbonate.