Perhaps you need a temperature controller that has a receptacle for the heat plate and that will turn the heat plate on and off more precisely than its internal controller. There are several different types of controllers that might work. Check some of the science outlets as well as Amazon.com and eBay.

Have you tried using a Peltier plate on which the temperature can be controlled using a voltage source? You can even get one from a hobby store. You'll have to check how stable they are though. I've not checked for that.

Another option would be to use a termperature-controlled water bath with a plexiglass or other material "box" placed in the water bath. Once it reached equilibrium, it should be stable. You would need a lid slightly above the water level.

Hi Kevin,

You might want to check this webpage (http://www.physitemp.com/products/HeatingandCooling4Scopes/ts-4.html). I personally use it and it allows you to make pretty fast changes in temperature. It works with a peltier and uses a water bath to allow you a precise control of temperature.

Hope it helps! 

skip the hot plate-Gates has a lot of measrurements as does my recent paper

Seasonal Acclimatization Determined by Non-Invasive Measurements of Coat Insulation

V.A, Langman

Mb- λEr = 1/I (Tb - Ts) Insulation - I (°Cm² Wˉ¹)

Campbell, G. S. and Norman, J.M. 1998. An introduction of environmental biophysics.

Se. cond edition, New York. Springer-Verlag. 286 p.

Cena, K. and Clark, J.A. 1978. Thermal insulation of animal coats and human clothing.

Phys. Med. Biol. 23-4, 565.

Gates, D.M. 1980. Biophysical Ecology. Springer-Verlag: New York

Hi Kevin,

You can build one using arduino. 

All,

Thanks for the ideas so far! I have a lot of things to look into now! 

If you want feather insulation values you know the body temperature (measure rectal or skin temps)  Metabolism is easily measured using a open system technique or from the literature; Ts the surface temperature of the feathers (IR gun measurement).  I tried your heated disk and no luck too many variables.  Call me Vaughan 970-472-1140

Vaughan,

I am not using live birds for this particular project; rather, I am using specimens. So, I need a heat source to put behind the skin and will use a thermal IR camera to measure the heat that escapes through the skin and feather coat. Ideally, what you suggest is clearly the best way to measure these things; however, the birds I am interested in have been dead for quite some time. Thanks!

Kevin 

It would be easy on live birds, but on museum bird skins harder.  Shouldn't make any difference what termp is behind the skin.  I think I would measure some live birds to make sure the measurements on the dead skins make sense.  I work with elephants and other big beasts, live no skins.