Anyone have experience with acurite thermometer/hygrometer?

I have an acurite hygrometer and I have it hanging at the canopies height. Just to check it's accuracy I set up my temp probe at the same height. After letting it sit for a while I notice the acurite reads 85 while the temp probe reads 75 at the canopy in the same spot. Anyone have any issues or experience with this unit in the picture?
 

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OldMedUser

Well-Known Member
The one with the higher temp is being more affected by radiant heat from the lights than the other is what's happening. Or one is way out of whack.

The thermometers should be off to the side to more accurately measure the room temperature. As long as you have good air circulation in the grow space the temperature should be even all over the room. If you want to know the temp at the canopy then use a digital temperature gun to get the temp of the leaves. I just got one recently on sale for $20 from Canadian Tire. Regular $100 so couldn't pass it up.

I was getting some bleaching on the upper fan leaves and when I checked with the new gun the temps were over 100F when the lights passed over the tops so I tried swapping out one of the 400W bulbs and putting a 150W in there but then my room wasn't heating up enough to actuate my exhaust fan so wasn't getting fresh air in there. Raised the hood and put the 400 back in and now it's working better all round.

I use two electronic thermometers in my room. One records the Max/Min of the heat and RH while the other just does temp but sends that info to my atomic clock on the wall just above my computer monitor so I can check it with a glance. I can tell when the exhaust fan kicks in by the 3 degree drop from the highest temp so I'm holding between 74 - 77F. Just about perfect. :)

:peace:
 

SPLFreak808

Well-Known Member
I've used accurite before and have had the same issues with 3 of em, the temp usually isnt too far off but humidity always read on the higher side compared to my lacross hygro. Also, do you notice the temp and rh% only move in 2 step increments? (68-70-72-74) its bullshit
 

OldMedUser

Well-Known Member
My temp and RH is displayed in 0.1 increments so it must be the type of equipment you have.

You can get remote gauges pretty cheap these days and all the ones I've seen display with .1 accuracy.

:peace:
 

OldMedUser

Well-Known Member
Farm supply store, Radio Shack, (Now called The Source), Walmart, Home Hardware etc. All over the place. I'm in Canada, northern Alberta actually, and even the small town hardware stores have things like that.

Indoor/outdoor weather stations are more expensive but the local farm supply sells a wireless remote thermometer/hygrometer for under $40. Then you don't have to run into the grow room to check all the time. I have a controller for my 6" exhaust inline fan that kicks in when the heat or humidity go above the settings that I have them at. A speed controller runs the fan at half speed so it's nice and quiet.

:peace:
 

SPLFreak808

Well-Known Member
Farm supply store, Radio Shack, (Now called The Source), Walmart, Home Hardware etc. All over the place. I'm in Canada, northern Alberta actually, and even the small town hardware stores have things like that.

Indoor/outdoor weather stations are more expensive but the local farm supply sells a wireless remote thermometer/hygrometer for under $40. Then you don't have to run into the grow room to check all the time. I have a controller for my 6" exhaust inline fan that kicks in when the heat or humidity go above the settings that I have them at. A speed controller runs the fan at half speed so it's nice and quiet.

:peace:
Well thats good to know they fixed it.. I noticed the ops pic is showing RH at 21 so it no longer looks to have 2 step increments.

I started with accurite, ofcourse the models from years ago lol i have since switched to a wireless thermometers like you mentioned and have found different readings compared to my old accurites.

I also overlooked the fact that he's heating his plastic sensor with IR causing wrong canopy temp readings.
 

OldMedUser

Well-Known Member
That should be as accurate as any of the other ones you'd buy anywhere. I keep mine on a shelf 6' away off to the side at about the same height as my canopy and a 12" oscillating fan keeps the air mixed up good in there so I get the temp of the air in the room which is what you want to know. The temp at the canopy under the lights is always going to be higher from the IR heat. If it's not too warm for the back of your hand at canopy height then it should be good for the plants. A fan gently blowing between the canopy and the lights can let you keep the lights closer without cooking the tops too.

:peace:
 

SPLFreak808

Well-Known Member
That should be as accurate as any of the other ones you'd buy anywhere. I keep mine on a shelf 6' away off to the side at about the same height as my canopy and a 12" oscillating fan keeps the air mixed up good in there so I get the temp of the air in the room which is what you want to know. The temp at the canopy under the lights is always going to be higher from the IR heat. If it's not too warm for the back of your hand at canopy height then it should be good for the plants. A fan gently blowing between the canopy and the lights can let you keep the lights closer without cooking the tops too.

:peace:
Yeah.. Not for me, quality varies with certain things.. Atleast with products sold in america not everything works perfectly.

Im a senior EE, i could accidentally kill myself at work if i overlook stuff like this but thanks for the tip

All 3 of mine wasn't accurate compared to every other one I've tried, thats all im saying for the sake of anyone who has issues with them.
 

OldMedUser

Well-Known Member
Hard to find anything that's not made in China anymore and I go out of my way to avoid buying Chinese goods. Like never shopping at Walmart. :)

I'm a chemist in a past life and have some decent lab thermometers so I can compare readings from the digital ones to those to make sure they are fairly accurate. I'm pretty fussy about accuracy. Being a Libra doesn't help. :D

:peace:
 
I have one of those acurite hygrometers hanging around canopy height, I put the temp probe in the same spot and hung it there for about a half hour. The hygrometer is reading 84 and the probe reads 79. The hygrometer is a small black box and the probe is just a metal shoelace looking wire with a metal nub on it. I'm guessing I should prob buy another thermometer to check?
 

OldMedUser

Well-Known Member
I have one of those acurite hygrometers hanging around canopy height, I put the temp probe in the same spot and hung it there for about a half hour. The hygrometer is reading 84 and the probe reads 79. The hygrometer is a small black box and the probe is just a metal shoelace looking wire with a metal nub on it. I'm guessing I should prob buy another thermometer to check?
Doesn't hurt to have more than one in the room to check but then which one is correct?

Really just need the room temp and RH so if they aren't sitting under the grow lights then you won't have higher readings than you should. Always going to be hotter and moister right under the light close to the plants where the moisture is coming from.

Good air circulation mixes up all the air homogeneously so knowing the whole room temp is what you want so either keep the probes away from the canopy or shade them with some foil or other reflective material so the radiant heat doesn't influence them.

:peace:
 
I've used accurite before and have had the same issues with 3 of em, the temp usually isnt too far off but humidity always read on the higher side compared to my lacross hygro. Also, do you notice the temp and rh% only move in 2 step increments? (68-70-72-74) its bullshit
Ya, it's quirky. I payed ten bucks for it. I think I am going to look into getting 2 better ones so I can compare readings.
 

Randodred

Active Member
That should be as accurate as any of the other ones you'd buy anywhere. I keep mine on a shelf 6' away off to the side at about the same height as my canopy and a 12" oscillating fan keeps the air mixed up good in there so I get the temp of the air in the room which is what you want to know. The temp at the canopy under the lights is always going to be higher from the IR heat. If it's not too warm for the back of your hand at canopy height then it should be good for the plants. A fan gently blowing between the canopy and the lights can let you keep the lights closer without cooking the tops too.

:peace:
Are these any good...
The acurite brand with outdoor sensor included?
 
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