Question: To find the stud in the drywall.
Option 0: Calibrate an edge finder by finding the density of the wall on the section without a stud. The move it along the wall from one side until it finds the edge of a stud. Move in from the other side to find the opposite edge.
Option 1: Calibrate an edge finder by finding the density of the wall on the section without a stud. The move it along the wall from one side until it finds the edge of a stud. Move in further to the same side to find the opposite edge.
Answer: 0