Difference between surface and substrate in temp with uth

[Artemille]

I'm pretty new but before owning a snake I did piles of reading. It's just the practical application that is getting to me now.

I have a ~40 gallon glass tank. It's being heated with two uth's and a small ceramic heat emitter bulb. The hot uth is on a thermostat set to 100F and the cool uth (its in the 70's without one) is set to 90, with the probe attached between mat and glass.

Hot side temp measured with temp gun on bare surface: 94
Hot side temp of substrate 1/2-3/4" thick with thermometer probe: 88/89

Cool side temp measured with temp gun on bare surface: 83/84
Cool side temp of substrate 1/2-3/4" thick with thermometer probe: 79

Ambient temps with temp gun are between 78-85

This all holds within 1 degree overnight.

Is it okay to have a 5-6 degree difference between the glass and the actual substrate? Are the temps in safe ranges? I use exo terra jungle earth. Thanks!

[FrankieCarbone]

How do u get ambient temps with a temp gun?

[The Serpent Merchant]

How do u get ambient temps with a temp gun?

You can't, temp guns only read surface temperatures.

To the OP:

The UTH you have on the cool side is 100% pointless. UTH's do not increase the temperature of the air inside the cage. You need to use a heat lamp or CHE to increase air temperatures.

Your temps are all fine, but you need to get something to measure air temps.

[Artemille]

Ooh, I guess it just read the nearest surface then. I just bought the temp gun and missed that. I have an ambient thermometer about 7" from the floor that reads 79F. I have a lamp with a ceramic heat emitter.

The cooler uth is warming the bottom. I know it doesn't heat air. Without it, the substrate was measuring under 74. I use it with the thermostat to bump it closer to 80.

[The Serpent Merchant]

Ooh, I guess it just read the nearest surface then. I just bought the temp gun and missed that. I have an ambient thermometer about 7" from the floor that reads 79F.

The cool uth is warming the bottom. I know it doesn't heat air. Without it, the substrate was measuring under 74. I use it with the thermostat to bump it closer to 80.

Air temperature in the cage is just as important as the cool side substrate temperature. As long as the air temp stays above 75 you are fine.

[Artemille]

Cool, thanks!

And don't worry. I edited my post to reiterate that I do have a lamp on with a ceramic heat emitter.

[FrankieCarbone]

You can't, temp guns only read surface temperatures.

Thats why i asked

[kitedemon]

You can't, temp guns only read surface temperatures.

To the OP:

The UTH you have on the cool side is 100% pointless. UTH's do not increase the temperature of the air inside the cage. You need to use a heat lamp or CHE to increase air temperatures.

Your temps are all fine, but you need to get something to measure air temps.

I would add any lamp will increase air temps I use fluorescent lights and led strings to do so.

UTh and other radiant heat sources only heat things not air they can raise a small amount but it is very limited.