How Can I Tell When My Air Tool Is Worn Out?
Accurate gaging with air tooling depends on the ability of the tool to produce consistent measurements, regardless of the tool's position within the workpiece. This means that the airflow and characteristics of the two jets must be "balanced". Since the air amplifier reacts to changes in this airflow, any position of the tool in the workpiece which reduces the airflow from one jet, must create a proportionate increase in airflow from an opposing jet. Jet diameters and "nozzle drops" must be identical, and on a common centerline with the outer diameter of the plug itself.
Any deviation in these two conditions of "balance" and "centrality" will cause indicator fluctuations commonly referred to as "total shake error". The following test procedures are recommended as the best methods of determining when an air tool should be removed from service. (Note these are only generalized recommendations and the results from each of these tests should be considered against the tolerance being measured with any specific air tool).
A New Dimension In Precision Measurement