Final answer:
A A. Surface plate is the correct device used as a reference surface for precision inspection and tool setup in manufacturing. It is known for its stability and precision, making it the industry standard for creating a reference plane.
Step-by-step explanation:
A device that is always used as a reference surface is a Surface plate. A Surface plate is a solid, flat plate used as the main horizontal reference plane for precision inspection, marking out (layout), and tooling setup. The surface plate is a common tool in the manufacturing industry and is often made from granite, due to its thermal stability, wear resistance, and ability to maintain high precision flatness. Surface plates are used to check the flatness of objects and to provide a precise reference plane for workpieces in metrology tasks.
Other options such as a Dial caliper, Gauge block, and Workstation surface serve different measurement purposes. A Dial caliper is a versatile measuring tool that can measure internal and external dimensions as well as depths. A Gauge block is a system for producing precision lengths. The Workstation surface is not typically known as a precision reference but rather a general work area. Therefore, the correct answer is A. Surface plate.