Given the information @hammy added, I was thinking...
Might it be better to test them all at a temperature near the expected data temperature?
And do you really need absolute accuracy, or do you only need them to be "calibrated" as a group? I'm guessing what you might be better off being able to "normalize" your data relative to the other sensors.
Trust me I've been involved in "accurate" temperature measurement numerous times in my career. You can easily drive yourself crazy chasing the holy grail of "absolute accuracy" especially with clone/fake sensors. I would be more inclined to verify they were stable and you knew how they related to each other. I'm going to take a guess here and guess your project was more about change and related temperature than absolute temperature.