Bullmark69
- 251
- 63
I’m sure you read the manual and have the IR gun set up correctly? Like is emmissivity user adjustable. You are measuring from correct distance?I know the answer but I can screw things up pretty good if given the chance…..so I’ll ask you folks.
I have 3 plants in a 2.5’x6’ closet with 8’ ceiling.
My light is an HLG 320 xl r-spec LED, hanging about 22” above the canopy. I bought one of those laser thermometers to check my leaves. I also have a couple other temp/humidity gauges in the closet. No matter what I do the laser always reads about 2F degrees above the ambient temps.
Right now for instance, I have 3 different thermometers in the closet that all read between 75.2 and 75.7F……so I feel like all 3 cannot be wrong. When I shoot the red dot onto one of the top leaves it’s reading 77.0-77.6F.
My understanding was w/ an LED the leaf surface temps will always be a couple degrees cooler than the air…..but mine says otherwise.
I’m guessing and hoping that the laser thermometer is off and needs to be calibrated, which cannot be done with this model.
Am I safe to assume that a 75F air temp will result in leaf temps of approximately 73F?
What’s the deal?
I’ve tried for the ideal VPD throughout the grow and just went off the air temp and subtracted 2 degrees but I figured I would ask about the chance of that reasoning being flawed.
It seems to be working I guess, as I’m in week 12+ of my light flip to 12/12 and the plants seem fine and should be ready in a week or two…..one actually has already been harvested so I’m down to 2….but I digress.
thanks for chiming in.
I know the answer but I can screw things up pretty
Depends on the health of the plant and the environment. If my leaf temps under LED was 2 degrees higher-something is wrong; not transpiring normal. Mine are 2-4 degrees below air depending on humitdiy and growth rate.I know the answer but I can screw things up pretty good if given the chance…..so I’ll ask you folks.
I have 3 plants in a 2.5’x6’ closet with 8’ ceiling.
My light is an HLG 320 xl r-spec LED, hanging about 22” above the canopy. I bought one of those laser thermometers to check my leaves. I also have a couple other temp/humidity gauges in the closet. No matter what I do the laser always reads about 2F degrees above the ambient temps.
Right now for instance, I have 3 different thermometers in the closet that all read between 75.2 and 75.7F……so I feel like all 3 cannot be wrong. When I shoot the red dot onto one of the top leaves it’s reading 77.0-77.6F.
My understanding was w/ an LED the leaf surface temps will always be a couple degrees cooler than the air…..but mine says otherwise.
I’m guessing and hoping that the laser thermometer is off and needs to be calibrated, which cannot be done with this model.
Am I safe to assume that a 75F air temp will result in leaf temps of approximately 73F?
What’s the deal?
I’ve tried for the ideal VPD throughout the grow and just went off the air temp and subtracted 2 degrees but I figured I would ask about the chance of that reasoning being flawed.
It seems to be working I guess, as I’m in week 12+ of my light flip to 12/12 and the plants seem fine and should be ready in a week or two…..one actually has already been harvested so I’m down to 2….but I digress.
thanks for chiming in.
^^^THIS^^^Candidly, it sounds like your plants are water stressed; although, not much if you’re only a few degrees over the ambient air temperature.
Here’s the important part for you OP: As water stress increases and cooling via transpiration decreases, leaf temperatures can increase well above air temperature.
Under ideal condition’s your plant will open the leaf stamatas and transpire to cool itself, cooling & transpiration increases and the leaf temp falls below the ambient air temperature. Under less than ideal conditions, the stamatas begin to close, cooling & transpiring decreases, and the leaf temp begins to rise above the ambient air temperature.
^^^THIS^^^
Thank you for trying to help educate an old fart like myself. Can you explain exactly what “water stressed” means?Candidly, it sounds like your plants are water stressed; although, not much if you’re only a few degrees over the ambient air temperature.
Here’s the important part for you OP: As water stress increases and cooling via transpiration decreases, leaf temperatures can increase well above air temperature.
Under ideal condition’s your plant will open the leaf stamatas and transpire to cool itself, cooling & transpiration increases and the leaf temp falls below the ambient air temperature. Under less than ideal conditions, the stamatas begin to close, cooling & transpiring decreases, and the leaf temp begins to rise above the ambient air temperature.
Do they look ok?- pics would helpThank you for trying to help educate an old fart like myself. Can you explain exactly what “water stressed” means?
Does it have anything to do with my watering habits? Or does it refer more to the low rate of transpiration, thus causing the leaves to stay warmer?
See my comments below b/c the causes for this just don’t seem to be present….but I could be sadly mistaken somewhere along the way.
Really, I do appreciate everyone that chimes in and tries to help a fella. Thanks again.
I’m growing in Fox Farms 70/30 buffered coco that I amended with different dry organics….my first attempt in coco.Do they look ok?- pics would help
I thought I’d update on my situation……I tried to calibrate my infrared thermometer and was left scratching my head.They look good and almost done. I wouldn't worry about it.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?