This graph shows the four most commonly used temperature sensors and how their voltage or resistance changes with temperature. There are plenty of diodes or diode-connected transistors that are cheap, easy to use, and provide decent accuracy, but measurements are typically limited to 200°C. Thermistors will cost a little more and are more difficult to design in, but will provide a little better accuracy and higher measurement range than a diode. RTDs provide much higher measurement ranges than thermistors and the highest accuracy among all the sensor types; however, they are the most expensive and may be just as difficult to design in as thermistors. Thermocouples are used in applications that require the widest measurement range. Costs and accuracies are comparable to a thermistor, but tend to be more difficult to design in because cold junction compensation is required, which calls for additional components.