Air Gauge Working Principle
An air gauge converts the clearance between a sensing jet and a surface into a pneumatic signal. The instrument compares that signal with settings established using masters, so it is a comparative dimensional system rather than a direct ruler.
Technical publication review required before indexing · Draft reviewed 13 August 2026
Engineering workflow
- Match plug, jets and instrument operating range.
- Use clean, regulated air and allow stable conditions.
- Set with traceable masters at the defined frequency.
- Control jet location, surface condition and contamination.
Worked example
As a bore becomes larger, jet clearance changes and the pneumatic signal moves along a calibrated comparative scale. The direction and scale depend on the circuit and instrument configuration.
Start an air gauge selectionLimitations and checks
- The relationship is not linear across unlimited clearance.
- Surface interruption, porosity, temperature and supply variation can affect response.
Relevant AccuTouch next step
Use the calculation as a screening input, then confirm the actual gauge, fixture, software or automation configuration.
View AccuTouch air-gauging instruments