How trustworthy are the thermostat temps?

Okay, let me rephrase my problem.

I am measuring temps a few different ways.
1. I have a thermometer with a probe
2. I have a heat gun
3. I have a thermostat

All of these devices are reading temps that are more than 5 degrees off from eachother. Which one should I use as a constant. Everyone is saying the heat gun but I keep getting such strange readings with it. I take a reading from the same spot and it says 100, then 98, then 95, then 100 again. That is not good. That is too much of a difference to know the actual temp.

I need to know which device I should trust to measure my temps. This has nothing to do with probe placement, I have my thermostat probe on the outside of the tubs and that is that.

Quote:

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Originally Posted by Kaorte

I have a johnsons controls thermostat hooked up to both my snake tubs. I have it set for 93*. I have the probe taped to the flexwatt outside the tub. I have been measuring temps all day and I keep getting crazy readings. I have used my thermometer with a probe inside the tub and it reads 85*. I use my temp gun (I am thinking its not very reliable :/) and it says 100* and the thermostat says 93*.

WHAT IS RIGHT??

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as for this the temp on the heat tape itself should be 93.
the heat gun typically will not be accurate reading on clear surfaces.
as for the thermostat probes being inaccurate typically most are within a degree or 2 at most! if your thermometer has a probe put it next to the thermostat probe and compare them. and with the heat gun you should be able to shoot the temp of the thermostat probe itself to see where the issues are.

Have you tried going around the house with the temp gun and the thermometer? If they still give crazy readings it's either broken or the batteries are dead.

And like nixer said, temp guns don't take good readings off of reflective surfaces, so are you taking temps off the substrate or the bottom of the tub?

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Originally Posted by DutchHerp

Have you tried going around the house with the temp gun and the thermometer? If they still give crazy readings it's either broken or the batteries are dead.

And like nixer said, temp guns don't take good readings off of reflective surfaces, so are you taking temps off the substrate or the bottom of the tub?

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Bottom of the tub, maybe this is my issue.

I am going to try what you said nixer. I will be back momentarily with news.

k, the temp gun gave me 94 next to the thermostat probe that was reading 92. So that sounds a little better.

I think it might be the reflectiveness of the tub that was throwing it off. Digital probe is hovering around 85 though :/

Waaah this is so frustrating D:

Like I said before, the digital probe measures roughly half surface temp, half ambient temps.

I only use my thermo/hygros to check up on temps and to see if the stats are doing what they should be doing.

I use my temp gun to check for the actual temps.

Quote:

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Originally Posted by Kaorte

k, the temp gun gave me 94 next to the thermostat probe that was reading 92. So that sounds a little better.

I think it might be the reflectiveness of the tub that was throwing it off. Digital probe is hovering around 85 though :/

Waaah this is so frustrating D:

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you think that is bad i have 3 of those on my incubator and my herpstat 2
my herpstat 2 reads 87.8 one thermometer reads 87.6 and the other one reads 73.6 and my temp gun reads 88

do you know now what you should be going by

Quote:

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Originally Posted by nixer

you think that is bad i have 3 of those on my incubator and my herpstat 2
my herpstat 2 reads 87.8 one thermometer reads 87.6 and the other one reads 73.6 and my temp gun reads 88

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Hmm.... I wonder which one is wrong....:rolleyes:

I just hate this guessing game crap!
I just want to build my rack and get everything stabilized!!
Right now I have two tubs next to eachother. Both tubs read different temps. Argh.

Quote:

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Originally Posted by Kaorte

I just hate this guessing game crap!
I just want to build my rack and get everything stabilized!!
Right now I have two tubs next to eachother. Both tubs read different temps. Argh.

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thats also why there is such a big range for the warm side. id set thermostat like 2-4 degrees over the temp your wanting and put a piece of paper towl in there and shoot that typically it wont be but maybe 2 degrees over what the tub bottom is with the paper flat on the bottom and no space between the tub and the paper