Air Gages and Air Gaging Systems

air gaging systems

WESTport Corporations Air Gaging division is your one stop shop for all of your Air Gaging needs. Air gaging products are manufactured in our state of the art climate/humidity controlled manufacturing facility.All manufactured air gaging products are traceable to the National Institute of Standards Technology (NIST). Calibration test methods are compliant to ISO/IEC 17025, ISO 10012-1 and ANSI/NCSL-Z540-1.

Full product line services include:

• Air Gaging • Air Rings • Air Plugs • Air Spindles •Air Snaps • Air Amplifiers • Air Accessories
• Digital Air/ Electronic Comparators • Calibration and Repair • Oil Well Gaging • Custom Design

Digital Air/Electronic comparators offer USB 2.0 interface, USB-RS485, plain RS232, RS485, Ethernet, Ethernet-RS485 communications and PC compatible data logging programming for SPC and SQC applications with no converter needed

Select your air gaging system and we provide all the equipment and air gaging products listed above for:

  • Edmunds Gages
  • Fowler
  • GAR
  • Mahr/Federal
  • Moore
  • Pratt Whitney
  • Sheffield
  • Standard
  • Universal Gage
  • Western Gage

air gage instrument

Air gages are designed to check a specific dimension of a part. Air gage instruments are designed to provide extremely accurate quantitative measurements of internal and external diameters of parts or workpieces.

air gages check external dimensions

Air Gages for External Diameters

Air Gages for Internal Diameters

air gages

Air Gaging Applications

image of a ring gage

Air Gage Calibration

digital comparators

Digital Comparators

oil well gaging system

Oil Well Gaging

Technical Info

Dimensional Gaging Forum: Air Gaging and How It Works

Air gaging is a technology that employs the use of air flow volumes and air pressure to determine the size of measured part dimensions. To achieve this measurement, it relies on the laws of physics, which state that flow and pressure are directly proportionate to clearance and react inversely to each other. As clearance increases, air flow also increases and air pressure decreases proportionately. As clearance decreases, air flow also decreases and air pressure increases accordingly.

Putting Air Gages to Work

Air gages, past to present, either measure flow or back pressure. Integrated air gaging systems are comprised of these basic components: air regulator, amplifiers, tooling, setting masters, connectors, and accessories. Let's take a look at each type of component and then examine various applications. 

Air Gaging vs. Contact Gaging

Contact gaging measures the dimension from surface roughness peaks of the part being measured (i.e. at plane A - A).

Open nozzle air gaging measures the mean surface of the part, which is approximately the average of surface finish peaks and valleys (i.e. at plane B - B). Technically, the mean surface would be an imaginary plane established by using the material from the peaks to fill the valleys until a level or zero line is formed.


It is perfectly natural that machinists should have an affinity for mechanical gages. To a machinist, the working of a mechanical gage is both straightforward and pleasing. Air gages, on the other hand, rely on the action of a fluid material, the dynamics of which are hard to (shall we say?) grasp. But air gaging has many advantages over mechanical gages and should be seriously considered as an option for many applications.

Checking Centrality

1.Calibrate the air gaging system using the max and min masters in a normal manner.

Checking Nozzle Balance

1. Calibrate the air gaging system using the max and min masters in a normal manner. 


"Air gaging is the greatest thing since sliced bread," a friend once told me. And he was right — air gaging is good. It's fast, high resolution, non-contact, self-cleaning and easy to use. For use in a high-volume shop, it's hard to beat. But that begs the question, "If air gaging is so good, why would you ever consider going back to contact type gaging?"