I am using a drolet Savanah wood stove with a double wall pipe on the top and picked up a thermometer and it says on the package to stick on single wall pipe or cooking surface. I called them and they said to place it on the double wall pipe and it will read 100 degress low on that pipe but I think it is more. If I place it on the pipe and the stove is burning with a nice solid bed of coals it is only reading about 125. If I place it directly to the top plate of my stove it reads 325 and that is the hottest I can even get it to read. I am burning dry wood oak and some is locust it has been all cut and split and stacked for about 3 years. I am not sure if I am even getting the right readings any place. Here is the links to the stove and the links to the thermometer I have.
Stove
http://www.drolet.ca/en/products/wood/savannah
Thermometer
http://www.tractorsupply.com/rutland-reg-magnetic-stove-thermometer-3198420
Stove
http://www.drolet.ca/en/products/wood/savannah
Thermometer
http://www.tractorsupply.com/rutland-reg-magnetic-stove-thermometer-3198420