Infrared Thermometer

what say you all on Infrared Thermometer's? would it not give you the most accurate measurement if you shoot it on the plants and area's around the plants? jw because i am thinking about getting one, i am having trouble with digi thermo's i am not happy with what i see so i am looking for the most accurate form off measurement in the grow room =)

I think most people may think its overkill? or just not a priority but yeah you can measure the surface temp of the leaves and shit.

I'm actually looking for one myself on ebay.
They seem like the most accurate but I'm almost thinking they are TOO accurate.
Why, becuase a leaf surface temp may be whatever but this may be that the leaf is actively cooling itself thru transpiration but the surrounding ambient air temp may be much higher. Kinda like how rock (stone) absorbs and releases ambient temp. The measurement of the surface of a rock is not really a measure of the atmosphere.
The problem is, all we hear are ideal temps for ATMOSPHERE, not surfaces.
A leaf may be 60 degrees but the air temp may be 75 degrees .
The temp of a bulb surface may be 150 degrees but it's only warming the ambient temp to 80 degrees for example.
In other words surface temp is not the same as cubic volume temp.
Also, these meters don't measure humidity which is related and I'd really like to see an IR temp/humidity reader.

IR's are great for measuring surface temps. I found mine very useful to help dial things in better. The main thing it helped me with was checking bud temps. In the room I had I found bud temps ranging from about 70F to about 85F. The happy zone seemed to be high 70's to low 80's. If low production seemed to suffer and if high quality seemed to suffer. Based on those measurements I rearranged my oscillating fans, redirected my intakes and also went from 2 300 cfm fans cooling 8 600 watt hoods to 3...problem solved then even canopy temps then happier plants then better quality and yield.

It's actually pretty much a toy really but can be helpful and did use it for some other things but not much. For most growers a waste of money. If you get one go for a model with at least 1% accuracy...they might even have better ones now. At 1% accurate a 77F reading can be +/-.77F and I found a great LCD probe thermometer from www.aquaticeco.com for like $20 and like .1F accurate...which was fantastic for checking the res and medium (rockwool slabs). Then there's the range of an IR with some having accuracy degrade pretty rapidly as distance from the point zapped/sampled increases so gotta keep that in mind too.

Mine was well worth the $150 I spent.

I have used these in industrial settings and can only tell you that the accuracy isn't really 100% accurate. If it says 100 it could be anywhere between 95 and 105 on a good unit (supposedly 1%). Like whatever said, distance will affect it as will disturbances in ambient temperature. I would say that was accurate enough, but it all depends on your use and if the money is worth it to ya.

Nomanishere said:

Like whatever said, distance will affect it as will disturbances in ambient temperature.

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I didn't realize ambient temp disturbances affected IR that much but been awhile since I researched the unit I purchased. Gawd...I did a quick look and it's the distance-to-spot ratio. Think mine was like 20:1 but it was like 2 years ago I bought it but very high quality cause I don't skimp. Good point...you not only have to look at the actual accuracy but distance accuracy. I sent my old IR thermometer to some IC guys down in San Diego so can't remember which meter...all I know is that unit was a very good one...wherever it is...lol.

The distance-to-spot ratio (D:S) is the ratio of the distance to the object and the diameter of the temperature measurement area. For instance if the D:S ratio is 12:1, measurement of an object 12 inches away will average the temperature over a 1-inch diameter area.

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From the almighty Wikipedia. So the 1% accurate meter I had would average the temperature over a 1" area when zapping from 20" away. So we're not only dealing with actual(?) accuracy (+/-%) but the D:S ratio also.

I've only ever had one use for an IR gun and that was fixing a truck that only had 3 cylinders running instead of 6, after stripping the engine down twice my dad finally gave up and my stoner logic kicked in and used the IR gun to notice that no matter what injectors we used the back three weren't firing. Turns out it was a blown fuse behind the transmission putting the rig into economy mode. Both my father and uncle were so pissed that they hadn't noticed and I was in the shop a mere 5 minutes before figuring it out.

Just a neat story thought I would tell about an experience I had with the tool... ended up saving my dad about 3600$ on new injectors.

lol i dont see how a TR thermo would have helped you there btw any one with any ideas on my best bet for a thermometer? cuzz like i say i am not happy with what i have now

Green Force said:

lol i dont see how a TR thermo would have helped you there btw

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Just zap the exhaust manifold right at the port area.

As for thermometers...in retrospect simple air type thermometers work just fine. Just make sure you don't have stagnant areas, easy to see just through simple observation. I could easily do without an IR. Mix the air up the best you can before it exits the room, make it tumble and swirl above the plants and also use an oscillating fan between the medium and bottom of the canopy. All that stuff underneath should be cleaned out anyway.

What are you not happy about? IR thermometers are actually not particularly accurate but can be helpful. If your hood is adequately cooled then all should be good with little radiant heat.

lol buddy i have 4 16" oscillating fans

CHECK OUT THESE FINDS

CHECK OUT THESE FINDS

I found a touchless infrared thermometer for 39.95 and a 60x x 100x pocket microscope for 15$ great cheap tools for the hobby grower. I will try them out if its worth the gamble for the cost

http://www.thinkgeek.com/gadgets/electronic/8024/?cpg=ab Infrared touchless keychain thermometer 2.5 +/- degree sensitivity

http://www.thinkgeek.com/gadgets/tools/9c42/?cpg=ab 60x -100x pocket microscope for resin inspection


it looks like a laser pointer that woudl fit on your keychain


Magic temperature device

Are you worried about the increasing entropy of the universe? Does the second law of thermodynamics keep you awake at night? Are you concerned that all matter is cooling to a state of equilibrium in an irreversible fashion? If any of these describe you then the Touchless IR Thermometer should come in pretty handy (or at least it'll keep you so busy checking the temperature of everything that you forget about the potentially grim implications of that stupid second law).

It's also kind of addictive and you'll quickly be looking for hot and cold stuff to check the temperature.

* Instantly check surface temperature in seconds
* Temperature range: -27 to 428 °F (-33 to 220 °C)
* Switch between Fahrenheit or Celsius display
* Accurate to +/- 2.5%
* D:S (Distance to Spot Size): 1:1
* Digital display
* Takes 2 LR44 batteries (included)
* Dimensions: 5" x .5"
* Note: not designed for testing internal body temperature

Some stuff you just have to pay up for to get a piece of equipment worth having. At 2.5% accurate a 77F temp could be +/- 2F. The Distance to Spot is only 1:1 so basically you have no range with it and need to be right on top of the spot you want to check. The sample area becomes too big and you're not really getting a good gauge of the temp of the spot you really wanna check. If you wanna get a solid IR of any real value I think you need to get something 1% accurate with the best D:S ratio you can afford.

I still think for most growers an IR is pretty much a toy and not necessary.

Whatever said:

Some stuff you just have to pay up for to get a piece of equipment worth having. At 2.5% accurate a 77F temp could be +/- 2F. The Distance to Spot is only 1:1 so basically you have no range with it and need to be right on top of the spot you want to check. The sample area becomes too big and you're not really getting a good gauge of the temp of the spot you really wanna check. If you wanna get a solid IR of any real value I think you need to get something 1% accurate with the best D:S ratio you can afford.

I still think for most growers an IR is pretty much a toy and not necessary.

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I would like use it to do spot checks of the outside temp of my 1 story bungalo everything is within reach

maybe check leaf temps under the cool tubes I run to see where the sweet spot is

for me after that it woudl be usefull to trouble shoot threal issues with electronics

i think 40 bucks is reasonable for a novelty

exspecially since the next step up at 250.00 is still 2% sensativity

http://www.testextra.com/pdf/extech/data_sheets/extech_42545_data_sheet.pdf

Even the fluke meters which cost 1000's have sensativity in 2% range

http://support.fluke.com/find-sales/download/asset/2150511_b_w.pdf

From Fluke 60 Series data sheet :

Accuracy -32 to -26 °C (-25 to -15 °F): ±3 °C (±5 °F)
(Assumes ambient -26 to -18 °C (-15 to 0 °F):

±2.5 °C (±4 °F) operating temperature -18 to 23 °C (0 to 73 °F):

±2 °C (±3 °F) of 23 °C [73 °F]) 23 to 510 °C (73 to 950 °F):
±1 % of reading or ±1 °C (±2 °F), whichever is greater Above 510 °C (950 °F): ±1.5 % of reading

so I find that a poor spec to compare by

the spot size is a fair issue but everything i would measure i well within reach

how many uses before it shits out and does it work as promised thats another story

ureapwhatusow said:

exspecially since the next step up at 250.00 is still 2% sensativity

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Don't know what to tell ya...got my old 1% accurate with a D:S ratio of 9:1 for like $150. Can't remember from where though.

Did some checking and pretty sure this was the unit I had and it's only $119 and it has a 20:1 D:S ratio! Sixth Sense LT300 and here's one place...
http://www.instrumart.com/Product.aspx?ProductID=18425

Whatever said:

Don't know what to tell ya...got my old 1% accurate with a D:S ratio of 9:1 for like $150. Can't remember from where though.

Did some checking and pretty sure this was the unit I had and it's only $119 and it has a 20:1 D:S ratio! Sixth Sense LT300 and here's one place...
http://www.instrumart.com/Product.aspx?ProductID=18425

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http://www.instrumart.com/assets/108/lt300.pdf

the other units are -/+ 2 degrees sensitivity on the farenhiet scale

the one you listen is -/+ 1 degrees sensitivity on a celcius scale

so the senstivity is the same, they all have the same sensitivity because they use the same tech to measure the temprature, i read this on site that explained how all the devices work.

Looks like a great gun for the cost if you need to take temprature readings that you physically cannot get to or are too hot to get close enough for spot readings but since im not reading furnaces or HVAC ducts in commercial buildings there is no benefit to pay more for nothing more than range

It's a useful tool. And it isn't overkill for me as it is something I use at work anyway.

ureapwhatusow said:

the other units are -/+ 2 degrees sensitivity on the farenhiet scale

the one you listen is -/+ 1 degrees sensitivity on a celcius scale

so the senstivity is the same, they all have the same sensitivity because they use the same tech to measure the temprature, i read this on site that explained how all the devices work.

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Just so we're clear the unit I listed is +/- 1% (and not +/- 1 degrees) C and 1%C converted to F is still 1%F meaning 1% of 25C is .25 which converts to .77F which is 1% of the C reading converted to F. Issue I see with the meter I recommended, and most likely others, is the meter is accurate to +/- 1% OR 1C (which is 3.08F) whichever is greater. If I'm understanding correctly for general grow purposes with 3.08F being greater than 1% of 77, which is .77, an IR is not so good a deal. The one you listed for $250 has a D:S ratio of 50:1 (great) with an accuracy of +/- 2% of the reading (2% of 77F is 1.54F) then also says +/- 4F/2C so assume if the 4F is greater than +/- 2% then the accuracy at room temp is more like 4F...I think???

Whatever said:

Just so we're clear the unit I listed is +/- 1% (and not +/- 1 degrees) C and 1%C converted to F is still 1%F meaning 1% of 25C is .25 which converts to .77F which is 1% of the C reading converted to F. Issue I see with the meter I recommended, and most likely others, is the meter is accurate to +/- 1% OR 1C (which is 3.08F) whichever is greater. If I'm understanding correctly for general grow purposes with 3.08F being greater than 1% of 77, which is .77, an IR is not so good a deal. The one you listed for $250 has a D:S ratio of 50:1 (great) with an accuracy of +/- 2% of the reading (2% of 77F is 1.54F) then also says +/- 4F/2C so assume if the 4F is greater than +/- 2% then the accuracy at room temp is more like 4F...I think???

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this is from the link you posted a spec sheet on your device

Specifications
Measurement Range -76 to 1400°F (-60 to 760°C)
Mode MAX, MIN, DIF, AVG, Probe
Operating Range 32 to 122°F (0 to 50°C)
Accuracy +/-1% of the rdg or 1°C, whichever is greater
Resolution (at -9.9 to 199.9°C) 0.1°C/0.1°F
Response Time (90%) 1 sec
D:S Ratio 20:1
Emissivity Adjustable from 0.10 to 1.00
Power Supply AAA x 2
Colors Yellow and black
LCD Dual
LCD Backlight On/Off
Class II Laser On/Off
Battery Life 180 hours (no backlight/laser)
Weight 6.3 oz (179 g)
Dimension (LxWxH) 3 x 1.5 x 7 in (72 x 39 x 175 mm) Approx.

1 degree C which translates to about 2 degrees F


I read somewhere, and I looked to find the link and couldnt readily find it, that the true temprature is calculated after some data is processed by the device, and the margin of error is relative to the general technology not the manufacturer. This percentage diminishes over a couple hundred degrees, but under 100 is standard to 2% F/ 1% C wish I assume to be rough it doesnt increase again until under 40 degrees or thereabouts so the range of temp we are concerned about will all operate at a couple degrees

I havent experienced a strain that a needs such finite temp adjustments that a 2-3 degrees from the target is an issue

In all other aspects they go from under 50 bucks to 1000's but i dont think you pay for greater sensativity

I think you get better DSO rating which could be critical for some
and from there its color displays, imaging upgrades and ect.

For 500 they had a crazy little unit that looked like full bloown FLIR display and all

other reasons for the prices scale is was it created for niche industries;
for example if its for the auto industry and you sepnd lots of money chances are you can beat the snot out of it and it wont break

i dont doubt you made a smart purchase, i just think that if you are interested in taking surface temps within arms reach a cheap FLIR pen will work (same technology as the ear thermometers) you can get comparatives on the outside of the house to checking hot spots in a PC case grow or in my case how close to the cool tube can I really get.

ARTofMAKINGfire said:

It's a useful tool. And it isn't overkill for me as it is something I use at work anyway.

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My luck it woudl be mistaken for a gun and i woudl get shot by off duty NYPD officers