Carbon Dioxide Meter (Capnometer)

Quick Answer: The Carbon Dioxide Meter (Capnometer) is an electronic instrument that measures the concentration of carbon dioxide (CO2) in a gas sample. A capnometer, strictly, measures CO2 in exhaled breath; this carbon dioxide meter is listed for education and laboratory use, and whether it samples breath or room air is confirmed on request.

Capnometer or Room CO2 Meter?

The two names in the title describe related but different instruments. A capnometer measures carbon dioxide in the air a person breathes out, usually reporting the level at the end of each breath; in hospitals it is part of patient monitoring. A room carbon dioxide meter samples the surrounding air and is used to judge ventilation, because exhaled CO2 builds up in occupied rooms that are poorly ventilated. Many instruments of both kinds use non-dispersive infrared (NDIR) sensing, in which CO2 absorbs a particular band of infrared light.

For teaching, either kind supports useful work. Students can compare inhaled and exhaled air, see how CO2 in breath changes after exercise, or follow CO2 in a sealed chamber containing germinating seeds, yeast or a plant kept in light and then in darkness. A room meter also turns a classroom into an experiment: readings rise through a lesson with the windows shut and fall when they are opened.

LabEquip does not present this unit as a medical device, and patient monitoring must use equipment approved for that purpose. Before ordering, confirm the sampling method (mouthpiece or sampling line versus room air), the measuring range and the display units. For data-logging projects, the wireless CO2 air sensor is another option.

Applications

• Comparing CO2 in inhaled and exhaled air in human physiology practicals
• Showing the rise in exhaled CO2 after exercise in sports science
• Following respiration of seeds or yeast, and photosynthesis of plants, in sealed chambers
• Checking classroom and laboratory ventilation

Specifications

Care & Handling

• Allow the meter to warm up in fresh air before taking readings, as NDIR sensors need a short settling time.
• Use a clean disposable mouthpiece or filter for each student if the unit samples breath.
• Do not breathe directly onto a room-air sensor; it will read high for some time afterwards.
• Check the reading in outdoor air occasionally; a meter that reads far from normal outdoor levels may need recalibration.

Why Choose LabEquip

Biology and physiology departments, sports science courses and schools monitoring classroom air are the usual buyers of CO2 meters. LabEquip lists this instrument in its General Lab Products range; ask LabEquip which sampling mode suits your practical.

Frequently Asked Questions

What is the difference between a capnometer and a CO2 meter?

A capnometer measures carbon dioxide in exhaled breath, usually at the end of each breath. A room CO2 meter samples the surrounding air to judge ventilation. Confirm which mode this unit uses before ordering.

Can this meter be used to monitor patients?

No. It is listed for education and laboratory use. Patient monitoring requires equipment approved for clinical use and operated by trained staff.

How does the meter detect carbon dioxide?

Many CO2 meters use non-dispersive infrared sensing. Carbon dioxide absorbs a specific band of infrared light, so the amount of light lost across the sample chamber shows how much CO2 is present.

What experiments can students do with a CO2 meter?

They can compare inhaled and exhaled air, measure the effect of exercise, follow respiration of seeds or yeast in a sealed container, and compare a plant chamber in light and in darkness.

Why does classroom CO2 rise during a lesson?

Everyone in the room breathes out carbon dioxide. With doors and windows closed, it builds up faster than fresh air replaces it, so the reading is a practical indicator of ventilation.

How should the meter be cleaned between students?

Use a new disposable mouthpiece or filter for each person, and wipe the outside with a damp cloth. Never wash the unit or spray liquid into the sample inlet.

Last Updated: September 2026