--- title: Photosynthesis Analysis CI-340 | CID Knowledge Base description: Access help on photosynthesis measurement, device operation, data interpretation, and technical troubleshooting. --- [Skip to content](https://knowledgebase.cid-inc.com/photosynthesis-analysis-ci-340#main-content) English Show submenu for translations [![CID green](https://knowledgebase.cid-inc.com/hs-fs/hubfs/CID%20green.png?width=350&height=77&name=CID%20green.png)](https://knowledgebase.cid-inc.com/) Open main navigation Close main navigation - English Show submenu for translations - [Submit a Support Ticket](https://cid-inc.com/plant-science-tools/leaf-area-measurement/ci-110-plant-canopy-imager/support/#SubmitaTicket) [Submit a Support Ticket](https://cid-inc.com/plant-science-tools/leaf-area-measurement/ci-110-plant-canopy-imager/support/#SubmitaTicket) How can we help you? - There are no suggestions because the search field is empty. 1. [CID Knowledge Base](https://knowledgebase.cid-inc.com/) 2. [Photosynthesis Analysis CI-340](https://knowledgebase.cid-inc.com/photosynthesis-analysis-ci-340) # Photosynthesis Analysis CI-340 Access help on photosynthesis measurement, device operation, data interpretation, and technical troubleshooting. ## CI-340 Handheld Photosynthesis System - [Videos demonstrating use of the CI-340 Handheld Photosynthesis System](https://knowledgebase.cid-inc.com/videos-and-resources-demonstrating-use-the-ci-340) - [To test the “chatter” in the rotary valve in the CI-340](https://knowledgebase.cid-inc.com/to-test-the-%C3%A2chatter%C3%A2-in-the-rotary-valve-in-the-ci-340) - [How do I calibrate the CO2 span in the CI-340?](https://knowledgebase.cid-inc.com/how-do-i-calibrate-the-co2-span) - [How do I operate the device in developer mode?](https://knowledgebase.cid-inc.com/how-do-i-operate-the-device-in-developer-mode) - [What does it mean if the Leaf Temperature (Tleaf) is negative?](https://knowledgebase.cid-inc.com/what-does-it-mean-if-the-leaf-temperature-tleaf-is-negative) - [How many measurements (counts) can the memory of the CI-340 store?](https://knowledgebase.cid-inc.com/how-many-measurements-counts-can-the-memory-of-the-ci-340-store) - [What does it mean if net Photosynthesis (Pn) is negative?](https://knowledgebase.cid-inc.com/what-does-it-mean-if-net-photosynthesis-pn-is-negative) - [When using the AD (CO2 and H2O Control) Module with the CI-340, my measurement count never increases and no data is recorded. Why is this?](https://knowledgebase.cid-inc.com/when-using-the-ad-co2-and-h2o-control-module-with-the-ci-340-my-measurement-count-never-increases-and-no-data-is-recorded.-why-is-this) - [CI-340 that is reading 100% humidity](https://knowledgebase.cid-inc.com/ci-340-that-is-reading-100-humidity) - [How long should a single measurement with the CI-340 take in differential photosynthesis mode?](https://knowledgebase.cid-inc.com/how-long-should-a-single-measurement-with-the-ci-340-take-in-differential-photosynthesis-mode) - [How can I tell if my soda lime is working and still scrubbing CO2?](https://knowledgebase.cid-inc.com/how-can-i-tell-if-my-soda-lime-is-working-and-still-scrubbing-co2) - [What are the specifications for a replacement CO2 cartridge for the CI-301LA?](https://knowledgebase.cid-inc.com/what-are-the-specifications-for-a-replacement-co2-cartridge-for-the-ci-301la) - [CI-340 photosynthesis measurement modes](https://knowledgebase.cid-inc.com/ci-340-photosynthesis-measurement-modes) - [How do I stabilize my photosynthesis measurements?](https://knowledgebase.cid-inc.com/how-do-i-stabilize-my-photosynthesis-measurements) - [How do I attach the AC adapter to my CI-340?](https://knowledgebase.cid-inc.com/how-do-i-attach-the-ac-adapter-to-my-ci-340) See less ▼ - [Root Analysis](https://knowledgebase.cid-inc.com/root-analysis#main-content) - [CI-602 Narrow Gauge Root Imager](https://knowledgebase.cid-inc.com/root-analysis#ci-602-narrow-gauge-root-imager) - [CI-600 In-Situ Root Imager](https://knowledgebase.cid-inc.com/root-analysis#ci-600-in-situ-root-imager) - [Canopy Analysis CI-110P](https://knowledgebase.cid-inc.com/canopy-analysis-ci-110p#main-content) - [CI-110 Plant Canopy Imager](https://knowledgebase.cid-inc.com/canopy-analysis-ci-110p#ci-110-plant-canopy-imager) - [Photosynthesis Analysis CI-340](https://knowledgebase.cid-inc.com/photosynthesis-analysis-ci-340#main-content) - [CI-340 Handheld Photosynthesis System](https://knowledgebase.cid-inc.com/photosynthesis-analysis-ci-340#ci-340-handheld-photosynthesis-system) - [Leaf Analysis CI-202/203/710s](https://knowledgebase.cid-inc.com/leaf-analysis-ci-202-203-710s#main-content) - [CI-710s SpectraVue Leaf Spectrometer](https://knowledgebase.cid-inc.com/leaf-analysis-ci-202-203-710s#ci-710s-spectravue-leaf-spectrometer) - [CI-203 Handheld Laser Leaf Area Meter](https://knowledgebase.cid-inc.com/leaf-analysis-ci-202-203-710s#ci-203-handheld-laser-leaf-area-meter) - [CI-202 Portable Laser Leaf Area Meter](https://knowledgebase.cid-inc.com/leaf-analysis-ci-202-203-710s#ci-202-portable-laser-leaf-area-meter) - [Software](https://knowledgebase.cid-inc.com/software#main-content) - [Rootsnap!](https://knowledgebase.cid-inc.com/software#rootsnap) [![felix logo 8-15-2019 transparent-1](https://knowledgebase.cid-inc.com/hs-fs/hubfs/felix%20logo%208-15-2019%20transparent-1.png?width=150&height=92&name=felix%20logo%208-15-2019%20transparent-1.png "felix logo 8-15-2019 transparent-1")](https://knowledgebase.cid-inc.com/) 123 Waverly Pl., Boston, MA 02135 [mailto:sales@cid-inc.com](mailto:sales@cid-inc.com) Copyright © 2024, CID Bio-Science