Maybe newer ones are, but my moms old mercury meat thermometer can not be calibrated/adjusted.Meat thermometers are great because they're easy to calibrate.
Human medical therms are the most accurate(manufacturing parameters), and in the right range.
Some good food thermometers can be calibrated/adjusted.
I used to do all this:
https://www.backyardchickens.com/ar...incubator-thermometers-and-hygrometers.73634/
Now use this one...https://www.thermoworks.com/RT301WA.