ABSTRACT
Sensors. One use for these gages is to employ differences in air pressure to determine the distance to a target object or the size of a hole. Following a calibration measurement on a master part, the air jet is directed at the surface of interest and the back pressure resulting from the air flow restriction is used to detect the proximity of the object. These sensors have good resolution, although they are limited to a relatively small measurement range. Therefore, they frequently are useful as golno go gages in those instances where it is necessary to measure the average characteristics of a surface or hole. Another use for pneumatic sensors is measuring the ability of a workpiece to maintain a specific level of vacuum or pressure over a period of time (leak testing).
