Why would the base resistance change? If it is one foot of 28 Ga Ni200 it will be 0.3778 at room temp (whatever you consider that to be in this case 68F) it will always be 0.3778 at room temperature. Why would you continually have to diddle with the value you already know?
Base resistance over time will change as the wire ages and you get buildup on the coil.