The most accurate device I have owned is a type K digital thermocouple from ebay from HK / China, it's dark grey with a orange cover. When I was calibrating it, surprisingly it was spot on.

I have another thermocouple, much more expensive with IR readings as well as K type thermocouple attachment.. the thermocouple over-reported by 2 degrees.

So what I recommend is test your equipment!

I also recommend thermocouples due to rapid response, inexpensive to replace (the HK one was like $20 shipped or less iirc), and accuracy once tested/calibrated.

I dislike digital thermometers due to their slow response.