The need for long-range height measurements has been around since the principles of lay out work became a fundamental requirement in machine shops.
The first step in the manufacturing process is to lay out a piece by transferring a design or pattern to a workpiece. This is performed in small shops, large manufacturing plants, and even by home hobbyists. The process may be used to begin a prototype piece or an emergency replacement part. The common tools for layout work include a surface plate, a surface gage with scriber or dial indicator, and a long-range height gage.