Air gauges are non-contact devices that utilize air pressure for measurement. They play a crucial role in ensuring precision and quality control in the manufacturing industry, from automotive to aerospace industries. They are particularly valuable for measuring delicate or easily deformable materials.

Air gages work well due to three main reasons: they are body-piloting type, use dual-opposing sensor method, and have a noncontact sensing component. These features are present in most air gage designs, including ID/OD air probe, air ring, and air length gages.

When air gaging was introduced, it provided the first high-performance 50u”/1um or better gaging on the shop floor. In fact, air gaging provided two breakthroughs for dimensional measurement.

Western’s Micro IIi Air Gage Readout provides fast and accurate measurements of internal and external diameters, tapers among other features.

In this article, I wanted to go beyond the simple go/no go measurements that most air gaging is used for. Air gaging is a highly effective and efficient way for measuring these simple diameter requirements. It is also extremely repeatable on tight tolerances, but for this article, I wanted to focus on using air gaging to measure form requirements such as roundness, flatness, perpendicularity/squareness, taper, straightness, matching, and others. 

All the buzz these days is about laser micrometers and vision systems. If you visit a tradeshow or get any online advertisement, many companies are promoting these measuring methods.

It seems that everyone is interested in noncontact gaging these days. Laser scanners, structured light, confocal chromatic sensors, and CCD cameras have all made significant advances in the last decade, leaving us to wonder if this century old technology is still useful today.

“Never before have mechanics and manufacturers, and in general has the world of industry, made use of gages and gaging systems as it is doing now..."

Air gaging has many advantages as an inspection method. It is quick and easy to use, and requires little skill on the part of the operator.

Air gages have been reliable tools for more than 70 years, providing accurate and repeatable measures of diameter, depth, parallelism, taper and flatness.