Temperature Controller

2 Deg for a 1500 Deg span translates into

+/- 0.13% based on Max Range, or +/- 0.26% Mid-range basis

typically, depending on your sensor you find that in the actual operating plants a mid-range error is +/- 6 to 7% on a good day,

you can get greater precision with national lab traceability, under lab conditions with special design platinum resistance sensors. In an operating plant, day after day, at temperatures >400C that is another matter...