The resistance change is a direct result of infrared heating and the corresponding tempera-ture change ∆ T can be characterized thanks to the approximately linear relationship between resistance and temperature characterized by α, the temperature coe cient of resistance (TCR) of platinum wire.
Breyting í viðnámi svarar til hitabreytingar í vírnum, en þar á milli er í mjög góðri nálgun línulegt samband sem lýst er með hitaviðnámsstuðli platínuvírsins, α.