You can make as many chips at a time as will fit onto the number of baking sheets that will fit into your oven. (Mine fits two baking sheets which is about what you need for 1 medium sweet potato.) The serving size entirely depends on who's eating—and how willing they are to share!
Preheat the oven to 225 degrees F. Line two baking sheets with parchment paper and set aside.
Peel the sweet potato and discard the skin.
Use a mandoline set on the lowest or second lowest setting—or about 1/8-inch thick—to slice into thin slices. Arrange on the baking sheets close together but without overlapping.
Bake for about 1.5-2 hours minutes, until dehydrated, curled at the edges, and they feel crispy to the touch. (Mine are usually done at 1 hour 40 minutes but it may vary depending on your slices.)
Let cool and serve.
Notes
These are best eaten on the day they are made, though they will stay crunchy if stored in an airtight container at room temperature overnight.
Cooking time will depend on the moisture levels in your sweet potatoes so let them go a little longer if needed.
You should be able to feel them to tell when they are crispy and done.