There is no other way than to use a NIST certified thermometer. Freezing and boiling doesn't work with these probes. That and you want to calibrate close to the temp you will be normally reading.
I have one I can loan to you. Or you can get the one I have at
I have one you could borrow as well. You can get a digit thermoeter at harbor freight for $11.99. They may carry it in stock and they are located in Dunwoody.
I saw this calibratable digital food thermometer on eBay and was thinking I could calibrate it against someone's precision thermometer and then take it home and calibrate my RKE. Thoughts?
And I love Harbor Freight...