How do you choose between RTD and thermocouple for temperature measurement?

Choose RTD when: high accuracy is required (0.1 degree C vs 1-2 degrees C for TC), temperature range is -200 to 600 degrees C, long-term stability is critical, or measurement is in a stable environment. Choose thermocouple when: temperatures exceed 600 degrees C (up to 1800 degrees C for Type B), fast response is needed (smaller mass), ruggedness is important, or cost is a concern. RTDs need excitation current and are affected by self-heating; thermocouples require cold junction compensation.