MultispeQ beginner questions

General Discussion

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Robert Walters

12 days ago

All,

I am just getting started with MultispeQ v.1 so please bear with me.

Q1: My instrument has a set of SPAD recalibration cards. How, and when, should these be used? I find no guidance anywhere.

Q2: It is not clear what exactly the trace parameters ECSt, vH+, gH+, are estimating, and their relationship to other parameters. Per the tutorial, these describe the accumulation of protons in the thylakoid through coupled ATP synthase activity. Kuhlgert et al. 2016 apparently grouped these parameters under "electrochemical shift (ECS)" but no reference is made to them. I have also come across the term "linear electron flow (LEF)", also unspecific. Can anyone point me to references?

Thanks.

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Robert Walters

6 days ago

Anyone out there?

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Sean

6 days ago

Hey Robert!

Sorry things have been very busy around the PhotosynQ lab as we are getting ready for the second version of the MulitspeQ.

Q1: The SPAD recalibration cards are included in your kit so that you can recalibrate at your choosing. When we shipped them, we thought over time the calibrations might drift, or devices would become dirty and people would want to recalibrate. However most people have chosen not to as the calibration has stayed firm for people. So I wouldn't worry about those.

Q2: I will include a link that goes through what the MultispeQ measures, and a definition of each. If you need more cleared up, I can get Dr. Kuhlgert in here to explain things a bit deeper.

https://photosynq.org/help/instruments_What_does_the_MultispeQ_measure

Best and sorry for the late response!!! Sean @ PhotosynQ

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Robert Walters

3 days ago

Sean,

Thanks for the reply. Re the SPAD cards, I'm curious how to recalibrate with them, if this was necessary: three cards each with four chromatic panels numbering from 1 to 12. Are there reference chlorophyll readings associated with each panel? What are these? This is the point I'm making.

Re Q2, I contacted a USDA plant physiologist about ECSt, vH+, gH+ and got very precise answers, thank you. FYI, the link for "additional information about MultispeQ parameters" in the Tutorial under Most Important Parameters is dead. Overall, your website is not easy to find pertinent information. For example, I found out that the instrument powers off after 3 hr on one of your linked videos. Shouldn't the power on/off parameters be given in the Tutorial and supplied with the instrument? I still don't know how to power off the instrument for brief periods of inactivity to save battery power. Which leads to: why isn't there a power ON/OFF LED? This is a no-brainer, IMO. Ditto battery charge status. There's no way to know what is the charge status of the battery. Your app should have a battery status indicator. This is crucial information for conducting multiple, day-long plant measurements in replicated trials. I would like to know whether the MultispeQ battery, like my phone, needs charging before proceeding to the next replication. Presently, I have no clue about this.

I watched David Kramer's YouTube video and found the quality is not good. I'm sure he's a great teacher, but he deserves better than this.

Please take this a constructive criticism. I think the MultispeQ is an innovative and potentially valuable tool, and look forward to analyzing the leaf photosynthesis data from our corn project.

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Sean

3 days ago

Lots of good questions and comments, hopefully I have some decent answers...

  1. Your SPAD cards should have come in a small manilla envelope with corresponding SPAD values for squares 1-12 (except on white/black squares) found inside. If you wanted to recalibrate, you could join two projects that I will link to at the bottom. When you run these projects through the desktop app, it will prompt you to place the cards in square by square and ask for the corresponding SPAD value.

  2. That dead link is a good find that we overlooked. However, that FAQ it use to be has just been replaced with that list of parameters I sent in the first post, so you're not missing out on any additional information.

I agree the website can be complicated to navigate and searching for pertinent information is non-existent, I can bring this up to some of the guys who maintain the website and see what they think we can do to make this easier for all users to find the info they want, without having to post in forums about it.

Concerning the power issues/LEDS... WE TOTALLY AGREE! When we first released the V1 of the MultispeQ an indicator light was overlooked and not included, but we heard this criticism multiple times and have included one in the upcoming V2 of the MultispeQ which should be released over the next few months. Hopefully the light will be able to change hue as battery levels change.

There is actually a few ways to tell battery charge level. One way is over the app, when you connect it should show a battery with a rough level of charge. Another way to tell is to attach the device to the desktop app and it will give an exact charge value. It would be nice to have the app show this more exactly when you connect, or be able to check throughout the day, unfortunately priority/resources are not being directed towards further app development at this point...

Also, I agree that video of Dave going over those parameters is poor at best. At the time there wasn't an emphasis on making great videos, but just to do the best with what was on hand. Since we have bought a few mics and maybe I can convince Dave to mic up next time he lectures and we can combine this with lecture slides and a better angle and more stable camera. Hopefully you can see some other videos we uploaded on the PhotosynQ Youtube page, the Getting Started playlist, which I'll link to below is better quality.

Thanks for all the comments, a hope and have a feeling you will have more :D

Some Links... Link for SPAD Recalibration Projects:

https://photosynq.org/projects/multispeq-v1-0-spad-recalibration-a?hl=recalibration

https://photosynq.org/projects/multispeq-v1-0-spad-recalibration-b?hl=recalibration

Link to Getting Started : https://www.youtube.com/playlist?list=PLL13ff_XAHcTJ9ODfJ6USwP8-5AVaag9e

Let me know if I glossed over anything