George,

if YOUR sensor today outputs 25.7°C, when actually having 25.0°C and repeatibility error is +-0.1°C, then tomorrow YOUR sensor will never output anything else than 25.6°C...25.8°C! (We neglect here any additional long term drift error.) Error will always be 0.7°C +-0.1°C = 0.6°C...0.8°C. So, whenever YOUR sensor outputs 25.7°C subtracting 0.7° (adding -0.7°C) will drastically improve accuracy of YOUR sensor. Of course, remaining +-0.1°C repeatibility error cannot be corrected for, and corrected sensor reading will always suffer from this remaining +-0.1°C error.

Repeatibility error is the key parameter of any sensor, because this is an error your sensor cannot be corrected for. If long term drift error is relevant, after some time sensor must be recalibrated. So, for high accuracy measurements the use of sensors with very low repeatibility error and with very low long term drift is essential. Only constant errors can be corrected by the help of look-up table.

Kai