YP Vernier - Version 1.0 With YP Vernier, it is easy to learn how to use a vernier to measure length with great precision. YP Vernier simulates a vernier caliper on the screen. Using a scroll bar, the user moves the movable jaw, and the corresponding numerical valu e is displayed on the screen. The program can also be used in "quiz mode": the movable jaw is placed at a random position, and the user try to find the corresponding measure.