Carbon dioxide recorder

Carbon dioxide monitoring instrument

A carbon dioxide recorder (or CO2 recorder) is a machine that can record the level of carbon dioxide at different times. It is more sophisticated than a carbon dioxide detector which only has to indicate the presence of carbon dioxide. There are three main types of carbon dioxide recorder: chemical, physical, and electrical.

## Mechanism

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### Chemical

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The chemical carbon dioxide recorder, sucks the gas through a chemical that absorbs carbon dioxide. They include the Simmance combustion recorder;[1] Hays automatic CO2 recorder, and electroflo CO2 recorder.

The Arndt carbon dioxide recorder used a potassium hydroxide solution to absorb carbon dioxide.[2]

The Uehling recorder uses the chemical, sodium hydroxide to absorb the carbon dioxide, and measures the change in volume of the gas.[3]

### Physical

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The physical carbon dioxide recorder, includes Webster CO2 recorder. The Remarex carbon dioxide recorder uses vanes spinning in the gas under test and the air.[4]

### Electrical

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Electrical recorders use a thermal conductivity method, where the resistance of a heated wire is measured.[5][6]

## Form

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Carbon dioxide recorders can be handheld, or wall mount. They can have an audible or light indicator alarm if level is too high. Units can also measure humidity and temperature.[citation needed]

## Application

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Carbon dioxide recorders have been used in schools and hospitals to determine whether enough fresh air is being circulated. A carbon dioxide recorder can be used to measure the composition of flue gas to check if combustion is at its most efficient.[3] In agriculture, they can be used to measure levels of carbon dioxide in greenhouses, where the levels are deliberately elevated.[6]

## See also

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* Explosive gas leak detector

## References

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1. ^ Levy, Leonard A. (1922). Gasworks recorders, their construction and uses. London: Benn Brothers. pp. 174–178.
2. ^ Levy, Leonard A. (1922). Gasworks recorders, their construction and uses. London: Benn Brothers. pp. 171–174.
3. ^ a b Uehling, E. A. (February 1912). "The Carbon Dioxide Recorder as a Factor in Fuel Economy". Journal of Industrial & Engineering Chemistry. 4 (2): 123–124\. doi:10.1021/ie50038a012.
4. ^ Bellman, Richard; Kalaba, Robert (8 November 2017). Classic Papers in Control Theory. Courier Dover Publications. p. 602\. ISBN 978-0-486-82593-9.
5. ^ Palmer, P. E.; Weaver, E. R. (7 January 1927). "Thermal-Conductivity Method for the Analysis Of Gases" (PDF). Technologic Papers of the Bureau of Standards. 18 (249): 36–99.
6. ^ a b Rosecrans, Crandall Z. (1 June 1927). "Automatic Gas Analysis Recorder for the Range of 0 to 35 per cent of CO_2 in Air". Journal of the Optical Society of America. 14 (6): 479–490\. Bibcode:1927JOSA...14..479R. doi:10.1364/JOSA.14.000479.