A bench comparator is an inspection instrument that holds a measuring device, such as a dial or test indicator. It allows an accurate comparison between a workpiece and a known standard. A bench comparator also checks the form of the workpiece, such as roundness and parallelism. It gets its names because it does not meaure a feature directly, like a micrometer, but instead “compare” a feature’s size to a setting master, such as a gauge block.
In addition to being used for rapid inspection and quality control, bench comparators are also used to measure the following:
- A single length or height of a workpiece
- Parallelism of a surface to another surface
- The difference between two heights
- The diameter of a workpiece
- The roundness of a diameter
- The taper on a diameter
The inspection process ensures part quality through accuracy, but when the inspection process takes longer than the manufacturing process, it slows down production and drives up cost. In all, bench comparators can often shorten the inspection time and improve accuracy.
