The way it works is you take a pea-sized amount of food, stick it in a one-time use capsule, and then plug it into a triangular sensor. The sensor then grinds up the food, mixes it with some chemicals, and then you wait about five minutes. If it tests positive for peanuts or gluten, you’ll see a symbol of a peanut or wheat chaff. If your dish tests negative, you’ll see a little smiley face. (To clarify, there’s a separate sensor for each allergen; one sensor can’t test for both.)
But at $230 per sensor, and $60 for 12 capsules, Nima isn’t a cheap system.