Temp fluctuation in incubator

jennibob · #1 (**permalink**) 20-07-2008, 08:37 AM

Right, Question

I have a home made incubator (pollybox,heatmat, microclimate mat stat)

and I am getting about a 5d variation in the temperature, I had a pulse stat but went bump a couple of days ago (typical)

The heat mat is attached to the top/lid and the probe is about 6" under the mad (in line with the tops of the tubs with damp vermiculite in), it has been running just under 24 hours nnow and still has a large temp variation in the temps.

it is for BD eggs which thankfully have not arrived yet so I do have time, but not much, according to my dates she is due to lay today, Is there anyway i can get a more stable temp in my incubator

Any and all advice helpfull,

Thanks

fixitsan · #2 (**permalink**) 20-07-2008, 10:07 AM

I would put the temperature probe closer to the mat. There is a time delay (called time constant) which has to do with the amount of time it takes between the mat turning on and the temperature at the probe rising. Once the probe reaches the desired temperature you can be almost certain that the mat has got hotter than the probe, and will continue to provide some heating even once it has turned off. This causes part of the cycling effect which your seeing.

How about putting the probe just inside the lid immediately underneath the mat. This assumes that you are using another thermometer inside the tub to tune the temperature. By making sure the tub is very well insulated along the sides you will also minimise heat loss, save electricity, and reduce temperature cycling even more.

Chris

jennibob · #3 (**permalink**) 20-07-2008, 11:02 AM

Quote:

Originally Posted by fixitsan

I would put the temperature probe closer to the mat. There is a time delay (called time constant) which has to do with the amount of time it takes between the mat turning on and the temperature at the probe rising. Once the probe reaches the desired temperature you can be almost certain that the mat has got hotter than the probe, and will continue to provide some heating even once it has turned off. This causes part of the cycling effect which your seeing.

How about putting the probe just inside the lid immediately underneath the mat. This assumes that you are using another thermometer inside the tub to tune the temperature. By making sure the tub is very well insulated along the sides you will also minimise heat loss, save electricity, and reduce temperature cycling even more.

Chris

Thanks, I will try that now and let you know how I get on

mask-of-sanity · #4 (**permalink**) 20-07-2008, 12:26 PM

Quote:

Originally Posted by jennibob

Right, Question

I have a home made incubator (pollybox,heatmat, microclimate mat stat)

and I am getting about a 5d variation in the temperature, I had a pulse stat but went bump a couple of days ago (typical)

The heat mat is attached to the top/lid and the probe is about 6" under the mad (in line with the tops of the tubs with damp vermiculite in), it has been running just under 24 hours nnow and still has a large temp variation in the temps.

it is for BD eggs which thankfully have not arrived yet so I do have time, but not much, according to my dates she is due to lay today, Is there anyway i can get a more stable temp in my incubator

Any and all advice helpfull,

Thanks

i have found the same with the microclimate mat stats there pulse ones are great though doesnt seem to matter where the probe is as even when i used one in a viv with the probe on the mat it was still giving a 4 degree difference

jennibob · #5 (**permalink**) 20-07-2008, 01:28 PM

Quote:

Originally Posted by mask-of-sanity

i have found the same with the microclimate mat stats there pulse ones are great though doesnt seem to matter where the probe is as even when i used one in a viv with the probe on the mat it was still giving a 4 degree difference

yeah, I have heard this about mat stats, but cash being what it is at the mo the quick fix was the mat stat, as soon as I am able to I will be replacing with a pulse.

i have managed to regulate the temps a bit more now,

Coming on a 82f and going off at 84f and keeping within those ranges,

Will these temps be ok or should I try to get them to around 86???

mask-of-sanity · #6 (**permalink**) 20-07-2008, 08:36 PM

Quote:

Originally Posted by jennibob

yeah, I have heard this about mat stats, but cash being what it is at the mo the quick fix was the mat stat, as soon as I am able to I will be replacing with a pulse.

i have managed to regulate the temps a bit more now,

Coming on a 82f and going off at 84f and keeping within those ranges,

Will these temps be ok or should I try to get them to around 86???

those temps will be fine thats what i incubate at

slither61 · #7 (**permalink**) 21-07-2008, 02:40 AM

Quote:

Originally Posted by jennibob

Right, Question

I have a home made incubator (pollybox,heatmat, microclimate mat stat)

and I am getting about a 5d variation in the temperature, I had a pulse stat but went bump a couple of days ago (typical)

The heat mat is attached to the top/lid and the probe is about 6" under the mad (in line with the tops of the tubs with damp vermiculite in), it has been running just under 24 hours nnow and still has a large temp variation in the temps.

it is for BD eggs which thankfully have not arrived yet so I do have time, but not much, according to my dates she is due to lay today, Is there anyway i can get a more stable temp in my incubator

Any and all advice helpfull,

Thanks

Hi all,

A mat stat is not accurate enough has too much variation as you have found out, my mat stats have been up to 4 degrees out it does not matter for a heat mat, it makes a lot of difference to incubating eggs it has to be accurate.

You need to get a pulse stat again.

slither61

webby06_2007 · #8 (**permalink**) 21-07-2008, 10:10 AM

i would get another pulse aswell,if you have got a dimming stat spare i have got a pulse stat spare if you want to do a trade just a thought

jennibob · #9 (**permalink**) 21-07-2008, 11:21 AM

Thanks for all the help guys,

I have managed to regulate the temps to between a 1 - 1.5d variant, (which I am very surprised at)

I have the probe directly under the heat mat and a digital thermometer where the eggs will be in the incubator, (average of 83.5 - 85d stable for 12 hours)

Thanks for the offer of the swap, and a couple of days ago, I would have snatched your hand off, (and may yet still do so) but whilst I have it settled and she is due to pop

don't want to risk messing with it.

Once again thanks for the help, and I WILL be getting a pulse asap.

Just waiting for eggs now lol *taps fingers impatiently on desk*

Jenx

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