Fig 1Dial indicatorHover to slide the carriageblock 1 · reads 18.0 px
Plunger and needle: what moves when the height changesThree gauge blocks, 18, 14 and 10 tallA dial indicator on a surface plate. Slide the carriage and the plunger rides up or down onto the block beneath it; one turn of the needle is 20 px of travel, so every block reads its own height.