Digital bore gauges for diameter measurements

mitutoyo digital bore gauges

The bore gauge is one measuring instrument used in the field of precision mechanics. Its main purpose is to accurately detect the internal diameter of circular holes.

In the more traditional version it is composed of a handle, to which rods of increasing size are assembled, until the dimension to be controlled is reached.

There are also more sophisticated versions in which the measuring contacts are contained inside a guide cylinder: this version is called measuring plug bore gauge.

In the smaller sizes (less than 20 mm) they are often used feeler bore gauges (also called spiked o with elastic head).

The bore gauge exploits the action of a comparator, which is connected to a mechanical system of lever and rods, contained in the handle, capable of connecting the axial movement of the comparator rod with the perpendicular movement of the two feelers; comparators can be used digital and analog, with resolutions al hundredth or thousandth of a millimeter.

In some cases, to facilitate the collection of measured data, instead of a comparator, the bore gauge is combined with a electronic probe (transducer) which, connected to a display or a PC.