Measurements, Protocols & Macros

Discussion about measurements, on how to create Protocols and Macros and about parameters returned.

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plantecophys R package

By Craig Whippo

The plantecophys R package can be used to calculate leaf-to-air vapor pressure deficit (LAVPD) using the measurements of ambient temperature, leaf temperature, and ambient humidity made by the multispeQ. The LAVPD might be useful measurement for some users.
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4 days ago


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How is leaf angle referenced?

By Miranda Haus

I am working up some data and found that leaf angle is important to my results. I read that the leaf angle was relative to the ground (https://photosynq.org/search/discussions/114), which means that a leaf parallel to the ground would have a leaf angle of 0. Correct? I am asking because my leaf angles range from 25-110. If the angles are using the ground as a reference,... read more
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8 days ago


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Interpreting SPAD 850 & SPAD 880 measurements

By Craig Whippo

I have a project with large differences in SPAD 850 & SPAD 880 measurements. Any ideas about what this measurement is indicating about biology? .
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18 days ago


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Measuring FvFm and light derived parameters

By Gonzalo Estavillo

Hello, we would like to measure FvFm after dark adaptation and then light-adpated parameters such LEF, ECS, etc. I am aware that there many protocol for measuring FvFm and the other parameters. However, would you reccommend one that measures both? or, would it be possible to run two protocols in series? For example, I am thinking of using Rodrigo's "10 - Fv/Fm - v1 - OK" an... read more
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4 days ago


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Need direction on qP formula

By Hellen Mwale

I conducted field experiments in which plants were not dark adapted. I have used qp, NPQt, PHiNO and photo protection in my report, but the formula which i know for qP is as follows; q P = (FM’ –Fo) (FM’-f’) I believe that this formula is for dark adapted. what formula should i use. lastly i need formulas for Photo protection. Please assist. Regards, Hellen.
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Nov 2018


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Whick software does the MultispeQ use?

By Zhangying Lei

Whick software does the MultispeQ use and plots as figure in the attachment,for example C++, java or R language?
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Nov 2018


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Measuring algae and cyanobacteria

By Tsai Lab

Hello! I was wondering how you would recommend taking measurements of cyanobacteria and algae. I suspect that you could use a cuvette but it is unclear the effectiveness and where to attach it. I saw in the tutorials and in prior forums that there is a way to do so, but I can't seem to find a protocol on how to do this. Thanks, Trevor
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25 days ago


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Phototaxis Protocol/Macros

By Craig Whippo

I am beginning to set up an algae phototaxis project for an undergraduate botany lab project. I would like to use the MultispeQ to provide the light treatments of different light qualities and quantities, and measure absorbance changes in a cuvette of algae. What is the easiest way to set up the protocols and micros? Is it possible to have a project with a sequence of pr... read more
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Oct 2018


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Ψ (ECSss) and ∆pH measurement

By Wojciech Baba

Hi, It is possible to measure with Ψ (ECSss) and ∆pH (ECSinv) with MultispeQ ? Would be so kind to help me to prepare the protocol ? I will try the simple protocol (below) but I not sure it is correct. Wojciech Baba [ { "pulses": [ 4000, 300, 3000, ], "nonpulsedlights": [ [ 2 ], [ 2 ], [ 0 ], [ 0 ] ], "nonpulsedlightsbrightness": [ [ "light intensity" ], [ "light intensi... read more
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Sep 2018


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RIDES Protocol

By Liam Dixon

Hello! Want to make sure I'm collecting data properly -- a tip given in the tutorials section is to 'know when the protocol you are using begins!' Does anybody know when exactly the RIDES protocol actually begins? Thank you, Liam
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Apr 2018


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ECSt on Small Leaves

By Sean

If my leaves are too small to cover the light guide, and I am trying to measure ECSt, should I be using a mask or not?
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Mar 2018


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PhiNPQ, NPQ(T) and FvP/FmP

By Weizhen Liu

MultispeQ v1.0 gives us both PhiNPQ and NPQ(T) values. Based on my reading of Tiet et al. 2017, PhiNPQ needs to be estimated after dark-adaptation but NPQ(T) does not. Using MultispeQ in the field with less than 1 minute measurement of each plant leaf, I think the leaf does not go through dark-adpation process before taking measurement. Can I say that NPQ(T) is more accurat... read more
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Aug 2018


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Using a macro to calculate stomatal conductance.

By Patrick S.

I'm looking to use the MultispeQ to measure stomatal conductance since existing protocols claim that they can estimate stomatal conductance via changes in air humidity and leaf temperature. I was looking at using the following protocol: https://photosynq.org/protocols/rides1_3_1 The corresponding macro is: https://photosynq.org/macros/rides1_3_1 I was wondering how I can... read more
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Feb 2018


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The protocol for Algae Photosynthesis

By Andriy Herts, Nataliia Herts

Hi, folk. Please help me. What kind of the protocol is the best for measure photosynthesis (V1) in algae (for example Chlorella vulgaris). I see only Algae Photosynthesis (under development).
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Oct 2017


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PhiNO

By Craig Whippo

My students are looking at how photosynthesis is changing over the course of fall phenology. Junker and Ensminger show that phiNO increases as chlorophyll is lost in maple leaves. This sounds reasonable to me based on the relationship between NPQ and pmf. However, my students are getting data from the multispeQ showing that phiNO is lower in yellow leaves. I don't under... read more
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Jan 2018


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What do raw traces actually mean

By Alejandro Morales

Hi, This may be a silly question but I cannot find any explanation on the website or the wiki from the Github repo. What exactly do the numbers in the raw traces mean? From some simple tests I have figured out they depend on both brightness and length of the pulses but I don't know what physical quantity is behind these numbers. My end goal is to calculate the fraction of... read more
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Sep 2017


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Phi2 predawn error?

By Jonathan R Pleban

Hi all, We've been measuring some plants in Growth Chamber before lights come on during predawn and would expect Phi2 approaching .85 at that time, instead the observations are all btw 0.7 and 0.5. PAR is only being measured at 4-5 umol. I think development of a protocol specifically for this FvFm of data is needed (and may already exist). Generally, caution should be us... read more
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Jul 2017


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ECS trace in Leaf Photosynthesis Multispeq V1.0

By Jonathan R Pleban

Why is pulselightbrightness = 150(40000/detector_read2)? and why is pulse length (-.000093detector_read2)+13.093 for the esc trace section in Leaf Photosynthesis Multispeq V1.0 protocol What are these values is us? Wondering as I am working of protocol development for some specific research applications Thanks, amazing product Jon
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Aug 2017


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Questions about ECS measurements

By Steffen Grebe

Hei, first of all I wanted to thank and congratulate you guys for the development of the MultispeQ. I’m having a great time with the instrument and analysis software. To get more familiar with the measurements I started to follow the induction of senescence in young and old rhubarb leaves after flowering using the “Leaf Photosynthesis MultispeQ V1.0” protocol. The first m... read more
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Jun 2017


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Leaf Photosynthesis protocol

By Taras Antal

Hallo, colleagues! I would like to clarify some points related to the basic Leaf Photosynthesis protocol. I wonder how Fm is estimated during short measurement in light adapted leaf? A protocol looks like a combination of PAM and FRR methods. Is this discussed somewhere? Taras Antal
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Jul 2017