Looks like I'm building a rack

Ok, so I goy my Herpstat a few days ago and hooked it up to my FLexwatt. I haven't built the rack yet, so I laid the tubs over the Flexwatt and set them on the carpet next to my bed. I set the desired temperature to 91, give or take .5 a degree.
Anyway, hooked up the probe and everything. Temps were good for a while, then put the tubs on there, and then the temperatures were all over the place. They were no lower than 87, but one of my thermometers said it reached 107!
I have three tubs on this one piece of 4'' Flexwatt, and all three read different temperatures at the same time.
Does Flexwatt have hot spots? Can you not lay it on carpet? What is the deal with this? Thermostats are supposed to rid you of events like this.
Any and all input or help is appreciated.
I don't want to have to get out the UTH's and lamp dimmers again.

Little help here guys

Hi,

Could it be because the carpet isn't a solid base that keeps the flexwatt at a constant distance from the tubs?

Are the tubs all sealed at the top to allow the heat to build up rather than escape as the next shelf in the rack would do?

Are there any drafts or other temperature affecting environmental conditions (windows, doors, ac units) ?

Have you tried just taking it on trust and building the unit? :P

Honestly not sure those are just a few ideas to help you get started figuring it out.


dr del

What are you using to read the temperatures on the bottom of each tub? (If you are using a heat gun put a piece of black electrical tape on the bottom of each tub to take your measurements on. Clear plastic has a really poor Emissivity, but I won't go into the details here how that could affect your readings.)

Pressure has a lot to do with heat transfer as well. I would try to put the flex Watt on a solid surface and the tubs as well. Put a couple pounds of weight in each as well. (2-4 lbs should be good.) I'm leaning towards #1 as your reading are higher than the probe on the flexwatt.

I have one Accurite thermometer in each tub. The probe of the thermometer is taped to the bottom where snakes lay, just above the heating element.
I'll try placing the tubs on a flat, hard surface, see what that does.

I put the tubs on a long piece of flat, thick paper. Amost cardboard.

I have readings of 88, 92, and 96 while the Herpstat is set to 89.

This is realy starting to %$^*&($ piss me off.

That's basically my plan for my rack!
And I'll make a rack for hatchlings when I'm on my way to breeding.

Hi,

Won't the paper still bend an flex too much?

Can't you try it using the shelving you plan to use to build the rack?

If it's not going to even out even then perhaps using some kind of sheet metal might help even things out? Hopefully you get it sorted.


dr del

Quote:

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Originally Posted by Papa Burgundy

I have sorta come up with a different design, and my buddy (amateur carpenter) said he would be willing to help.
I am going to use 11 inch Flexwatt for my 41 quart tubs, but I don't need it for any of the other ones. I wanted to use 4 inch Flexwatt for the smaller tubs. I know the different sizes of Flexwatt run different wattages, so would I be able to use the same thermostat for both heat tapes?

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You could get the herpstat 2, which has two outputs.

Hope this helps.

I'd build the rack and then test. Comparing the temps while on the rug is a good effort, but its like comparing apples to oranges.

Build the rack, then test out your temps. They will vary some what... but as long as they are within limits you should be good.

Keep in mind, if the tstat is not proportional, then temps will vary from your setting either up or down 5 degrees...