Thermocouples are less accurate than other sensors.
Accuracy is highly dependent upon installation. Variations in wire composition, homogeneity, or even strain can affect thermocouple readings. Thermocouples are interchangeable and respond to standard response curves. Lake Shore sells only uncalibrated theormocouples. While thermocouples can be calibrated, calibration must be performed in situ because the entire length of wire contributes to the output voltage if it crosses a temperature gradient.