Thermometer location?

tyke1973

Well-Known Member
Ya better of with one with a probe on,that you can have the piece that reads that temps above the plants. so its same height getting same heat for a good reading
 

Dr. Who

Well-Known Member
Yes

Location is key to a stepped temp range.

Pot level - mid to upper 60's
mid plant - lower 70's
canopy - upper 70's

Place the thermometer just below the canopy top and regulate to match as close to the list as you can. Some movement may be needed to adjust to those goals.
 

Kingrow1

Well-Known Member
If I place my digital thermometer directly infront of my light will it read a higher temp than it really is?
Yes, it will read light radiation which will give false and higher readings than air temoerature.

You want the thermometer out of all light direct and in direct, this is the true way all science uses for air twmperature.

Heat is three things, conduction convection and radiation not one simple thing.

Temp sensors are not best placed in the canopy. There is far too much confusion here :-)
 

AndromedaM31

Active Member
Theres just no way I can place it canopy height without it being in direct light, I'd have to put it just below the canopy hanging from the scrog board
 

Kingrow1

Well-Known Member
The problem comes when indirect or direct radiation makes folks thing hps is hot or makes em blast extraction in some effort to cool but really you end up making a wind tunnel.

Reading exact air temp is much harder than you think, mainly it will be close to the air outside the tent.

It is quite the discipline to get this stuff all right :-)
 

AndromedaM31

Active Member
Man it was reading at 82 where It was before infront of the light, and now its reading 73 where its hanging below the scrog board. Using infrared thermometer the canopy reads between 74-77
Sound about right?where its located Should I expect it to read a little less than it really is up above?
 

AndromedaM31

Active Member
Lol you're right, it's starting to confuse me a bit.
What should I have it reading right where it's at to be the proper temp? Atleast an approximate reading​
 

KryptoBud

Well-Known Member
Lol you're right, it's starting to confuse me a bit.
What should I have it reading right where it's at to be the proper temp? Atleast an approximate
Under the light the thermometer reads hotter because of radiant heat from the light. When you stand in the shade it feels cooler but the air temp is the same. Another example would be hot top, it can get significantly hotter in the sun than the air temp is.​
 

Kingrow1

Well-Known Member
Lol you're right, it's starting to confuse me a bit.
What should I have it reading right where it's at to be the proper temp? Atleast an approximate reading​
Infared thermometers are for vpd equations and not air temperature readings as far as i know unless they have one which somehow reads the air and not the surface of the leaf or whatever its aimed at.

Now shade your thermometer and place away from the light.

You see why some stop using them altogether and just read the plants, i now my tent never exceeds max temps so i dont use one these days.

keep at it youll suss it :-)
 
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