What is Accuracy?

NIST defines accuracy as: closeness of the agreement between the result of a measurement and the value of the measurement or “true value.”

Thermocouple accuracy is typically defined by the type of wire used, i.e. Standard Limits of Error (4.0°F) and Special Limits of Error (2.0°F). Unless otherwise noted, ThermoWorks employs high performance thermocouple wire with tighter tolerances than Special Limits of Error wire over common industrial ranges in its probe construction. Probe tolerances are listed below:

Type Description Termperature Range (Probe Dependent) ThermoWorks Probe Tolerances
K Nickel Chromium/ Nickel Aluminum
(Ni-Cr/ Ni-Al)
-346 to 2500°F
(-210 to 1372°C)
±2.7°F (1.5°C) from -40 to 32°F (-40 to 0°C)
±0.9°F (0.5°C) from 32 to 212°F (0 to 100°C)

±2.7°F (1.5°C) from -148 to 631°F (-100 to 333°C)
±0.4% from 631 to 1832°F (333 to 1000°C)
T Copper/ Constantan
346 to 752°F
(-210 to 400°C)
±0.9°F (0.5°C) from -40 to -4°F (-40 to -20°C)
±0.4°F (0.2°C) from -4 to 158°F (-20 to 70°C)

±0.9°F (0.5°C) from -40 to 257°F (-40 to 125°C)
±0.4% from 257 to 662°F (125 to 350°C)