Copper has a very linear resistance to temperature relationship but, since copper oxidizes at moderate temperatures, it should not be used over 150 Celsius copper resistance temperature detector is are commonly used in winding temperature measurements of motors, generators and turbines. 10 ohm copper resistance temperature detectors have been most common over the years but are now giving way to 100 ohm and even 1000 ohm models to get better resolution thus providing a more accurate measure ment.