Material which can be used for resistive heating and simultaneous temperature measurement

I want to embed a wire inside a plastic and heat it to specific temperatures (80$^\circ$C 100$^\circ$C 130$^\circ$C 180$^\circ$C). I want to find a material that is resistive enough for resistive heating, but also I want the wire's resistivity to vary fairly strongly with temperature - this way I can know the actual temperature that I'm getting by looking at the resistance during the heating process.

My problem is that I cannot seem to find a material with the properties I want. I tried nichrome wire and carbon fibers, and while they are resistive enough to give me heat, their resistance does not change enough (for my desired temperature ranges) to be measurable with my setup.

• What's the question, exactly? Are you asking how to use a wire to heat plastic while measuring the temperature of the plastic? Or do you want to measure the temperature of the wire? Are you asking where to find "properties of materials?" Are you asking what kind of wire to use? – Air Apr 24 '15 at 22:54
• Sorry for the confusion. Yes I am essentially asking for what wire to use. However, I would not be opposed to hearing some new ideas on how to achieve my goal. And no, running a thermocouple next to my heating wire is not an option for my application. Thanks. – Nic Apr 25 '15 at 8:32