Also, there apparently is something called "Constantan" -- a metal compound (usually) made from 55% Copper and 45% Nickel (at least according to Wikipedia): ht

Also, there apparently is something called "Constantan" -- a metal compound (usually) made from 55% Copper and 45% Nickel (at least according to Wikipedia): https://en.wikipedia.org/wiki/Constantan https://en.wikipedia.org/wiki/Constantan >"Its main feature is the low thermal variation of its resistivity, which is constant over a wide range of temperatures." In other words, NOT a square relationship nor even a linear one(!) -- in the temperature range where Constantan's resistivity is constant... (At least, according to Wikipedia...)