In addition to the linearity, the sensing tolerance is another key factor when choosing a thermistor. The chart on the right shows the sensing accuracy window of each thermistor tolerance type: ±1% (red lines), ±3% (green lines) or ±5% (blue lines). At 85°C, a ±1% type achieves ±1.8°C accuracy, while a ±5% type provides ±3.0°C accuracy in the example. Since tighter tolerance parts do have a cost premium, it might be best to consider the loosest tolerant part a design can withstand.