we are talking about metal, plastic and wood. these are the 3 categories of material that the robot shall gather. i have found the emissivity of these materials, but i still don't know if the device needs an external IR thermometer in order to calculate the emissivity at the current temperature.
so the only thing i have to do is remove the power supply box of the device and connect it directly to my batteries. nice. hope it works. still haven't got an answer from the company about the temperature thing. thank you very much. your advice gave new aspects to look at in creating the robot. do you know how much current a device like that could demand? they don't write a thing about that in the specs. not even watt consumed. nothing!!! i send them an e-mail but stilll nothing. thanks again.