Public Lab Research note


Testing PhotosynQ in a greenhouse

by gbathree | January 20, 2014 16:50 | 46 views | 6 comments | #9960 | 46 views | 6 comments | #9960 20 Jan 16:50

Read more: publiclab.org/n/9960


Just made a new post with some new data taken from a nearby greenhouse using MultispeQ. We successfully tested a few different measurements, specifically photosynthetic efficiency (Phi2), SPAD (chlorophyll content), photosystem I activity, light level, CO2 content, temperature, and relative humidity. The data looks really good!

We also made a significant improvement in our detector to reduce noise. I think this will allow for a great deal of other absorbance type measurements for trace contaminants in water or soil, so if anyone has specific methods for detecting contaminants using absorption or fluorescence I'd love to hear them and try them out.

Here's the link with more info: http://photosynq.org/great-news-less-great-news/


6 Comments

hi Greg - very cool -- what are your plans for testing against some known devices? Also, if you have better resolution than other techniques, what how do you make a comparison?

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Right now we've been testing photosynthesis measurements on the MultispeQ against known devices in our lab. However, most things in our lab aren't 'standard' devices - we have a lot of specialty machines which are very accurate but not cheap. So we'd love to get beta testers to do some direct comparison against commercial handheld fluorometers and SPAD meters - many beta testers are plant science folks who have these tools on hand. If we don't get a lot of help there, then we'll do it ourselves here, but we want to try to focus on efforts on developing the equipment and website if possible and we have limited cycles.

It's a great question about how to compare better resolution... The way we've done it now is to look at the raw data points and measure the noise (imagine for example 300 data points with a mean of 900 and a standard deviation of 50 where ideally they should all be the same). Many devices (like the LiCOR 6400, or benchtop flourometers like we have in the lab) do output the raw data so in those cases we can simply compare how noisy their signal is versus ours. A different device or technique which does not output the raw data but instead just outputs the finished calculated value we won't be able to compare directly noise levels, but we could take several measurements on the same sample and see how much noise there is on the finished calculated value.

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When can buy. Thank you.

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Still working on it. We made a revision to the detector which delayed us a bit. We're shooting for early march to ship. As a result, the beta sign ups are still open, so you can sign up here: http://photosynq.org/beta-test-application/ . Then you'll receive an email to confirm your interest, and then we'll contact you once we're ready to ship.

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Hi Greg - did you see the thing I posted about fluorescence imaging? https://groups.google.com/forum/#!topic/publiclaboratory/dbr63tX8ZyM

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No - sorry I missed it. I'll go check it out and respond there -

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