There are different types of air gauges. One of these is the air plug. The air plugs are gauges that are used in evaluating slot dimensions and hole as well as locations where there are specific limits of tolerance. They are of absolute production quality. The air rings are also functional gauges and at the same time production-quality. They are typically used in evaluating certain types of tolerance with the dimension or attribute of threaded studs, pins or shafts. Air gauge stations are huge and complex units. They are available in either floor mounted arrangement or in bench top. The air gauge heads work also with other gauges to connect remote analog amplifiers, displays and readouts.
How does air gauges measure dimensions? It uses changes in pressure or changes in the flow rates in order to measure dimensions as well as determine the attributes. Master restrictor jets are used by back pressure systems. Adjustable restrictions or bleeds are also used to measure the change in pressure and also in adjusting the change in air tooling. Tubes are used in measuring the flow rates in flow systems through the nozzles, air jets or orifices. The back pressure systems offer a lower range than that of the flow systems. It also has more sensitivity and versatility.
The gauges in a flow system require much higher volumes of nozzles and air. They are useful when you are required of huge measurement ranges. The different kinds of back pressure systems that have a third zero setting restrictor are the balanced air, differential, zero setting and the single master air gauge systems.
Generally, gauges and other measuring instruments are used to measure clearance, trueness, diameter and depth. Some of the more popular mechanical gauges are the following:
Calipers: These gauges are used to measure the internal as well as the external sizes of objects. That being said, there are two types of calipers, the inside and the outside caliper. There are other types also namely the divider caliper and the odd leg caliper. Some of these calipers come handy with a measuring scale.
Micrometer: The micrometer is effective in measuring small distances and is much accurate than calipers.
Telescopic feeler gauge: This type of gauge is also called as the tongue gauge. It is made up of a long feeler gauge inside a curved edge or one that is shaped liked a tongue. The elongated feelers protrude so that you can insert it in remote, inaccessible places where the feeler cannot reach.