Infrared Leaf Thermometer Build

Hi all,

Just finished a prototype non-contact thermometer to measure leaf surface temperature and hence a more accurate vapor pressure deficit.

It is a little rough around the edges but it is sending real time measurements to my dashboard. My software saves all my measurements: lighting, temperature, humidity, etc… every 60 seconds to a file so I can view trends and see relationships between readings.

This morning I was reading about a 5 degree difference between leaf surface temperature and ambient air temperature. VPD was about 1.3. This was after I did a watering.

Yesterday leaf temperatures were running 2-3 degrees below ambient.

It uses a medical grade IR sensor with a 5 degree field of view. My mount is a little rigged but it holds the leaf stationary in front of the sensor and has just enough tension that it shouldn’t damage the leaf.

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thats an awesome build, well done

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Holy moly. u should get a patent if it keeps working. Good luck and have a great harvest

Thats really cool man! Keep up the good work maybe there is a patent coming soon and a new tool for my Arsenal

@BudzMS, @beachglass, @BigCat420 thanks guys for the compliments. I doubt there will be any patents coming but I will share any info you guys want on components.

I am mainly interested in studying transpiration rates, so far I have learned transpiration is very low during lights out, it was really flying right after I did a watering and now leaf surface temperature is running 2-3 degrees below ambient temps

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I dont think I could put t together lol

I can’t even get the towel to stay around my waste after a shower i will hurt myself trying this

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One of the coolest engineering feats I’ve seen on here. Very nice

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haha… I know what you mean about the towel thing

Thanks, but you guys give me too much credit. Is interesting what one can do with popsicle sticks and binder clips.

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I just love making things. So I love watching other do it too

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@AxisCat Sweet! I have been trying to use a laser temp checker… But cannot find the correct emissivity setting for cannibus leaves.

I would love it if you’d post a parts list and detailed assembly instructions if your up to it…

I’ve got plenty of product design/engineering experience and own SolidWorks 2017 SP5, and a certified SW expert… If you want 3D models, assemblies and prints let me know.

Great job and idea!

Hi @Fiefie. Thanks for compliment.

My research shows the average E value for a typical green plant leaf is .98 +/- .01. So your typical IR thermometer is calibrated to 1 which is very close.

The sensor I selected is a MLX90614ESF DCI made by Melexis. They offer a family of sensors based on the MLX design. I chose the DCI prefix which is the 5 degree field of view. The larger the field of view the larger the circle on your object used for calculating temperature. Might be cautious of that.

This sensor also has the ability to program values into the eprom. Like the emissivity value if you did want to change it to something other than 1.

It communicates with ‘other’ devices via an I2C protocol which is commonly used with small programmable microcontrollers (MCUs). So this sensor will require other components to acquire the data then display it to the user.

I use a NodeMCU board operate all my sensors. Temperature, humidity, LUX, CO2 and of course this sensor.

Does this give you a lil to get started with? I am happy to answer any questions I can.

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@AxisCat Ahhh IoT! I have wanting to play around with it. Nice!

Do you have pics of the NodeMCU board with all the different sensors?

Your system seems better(logging wise) than my…hygrometers(govee), and inkbird controllers.

What do you hook the board to… Pc, laptop, windows, Linux, ios? Via USB, serial?

It is a rat’s nest of jumper wires! Been working on it for about 2 years now:

I have a couple of relay boards that control all the lights, fans, AC unit, humidifier, dehumidifier… basically everything is controlled by this single NodeMCU

It sends data back and forth over my LAN network using MQTT protocol. I have a front end I made with visual basic for my interface:

It is a work in progress…

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@AxisCat F’in awesome!

im lost just looking at it lol

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it is busy… I probably need to go ahead and update my schematic… haven’t done that in a while

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Thanks!

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Hola @AxisCat just wanted to let you know the offer to model up stuff for you on SolidWorks is still open. I do believe there’s circuit board design module on their as well.

A bit bored… Just finished modeling a train layout… It’s not product design nor tooling engineering… But relaxing for sure.

Again… Great idea and job?

Updated it over the last year?

I had found this on the internet… That reminded me of you… And to here now…

They don’t list prices.