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.
@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
@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.
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.
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:
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…
