Automated CO2 injection system with analogue and digital outputs for measuring photosynthesis in crop enclosures
✍ Scribed by A.F. Stevens; B. Acock
- Publisher
- Elsevier Science
- Year
- 1978
- Weight
- 442 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0002-1571
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✦ Synopsis
Stevens, A F and Acock, B., 1978. Automated'CO: rejection system wlth analogue and dlgltal outputs for measuring photosynthesis in crop enclosures Agrm. Meteorol 19 113--120.
An mexpenslve CO: injection system is described. The system, used m conjunctlon wth a CO: meter, can automatically inject known amounts of CO: into a plant enclosure to maintain the CO: concentration and measure plant photosynthetic rate. When the CO2 meter senses that the CO: concentration In the enclosure has fallen below the desired value, a bellows pump withdraws CO2 from a supply hne through a demand valve and injects the CO2 into the enclosure. Once a pump stroke has been mltiated, the pump always completes the full stroke. Each pump stroke is counted, recorded on an impulse counter and converted to a standing analogue voltage for data logging Pump operatmn Is mhlblted while the logger is interrogatlng the circuit and the analogue slgnal is reset to zero after each interrogation