PNEUMATIC GAUGING SYSTEM A.K.A. AIR GAGING SYSTEM A.K.A. AIR ELECTRIC CONVERTER

摘要

The present invention relates to a pneumatic gauging system, which is in the form of a single block having appropriate air passageways bored therein.;Compressed air is supplied to the input of the system and its output is connected to an air probe. Parts to be gauged, are placed on a fixture which incorporates the air probe. The proximity of the part, to the nozzle of the air probe, creates a restriction which causes the air speed in the passageway to vary proportionally to the size of the part.;A transmitter, at the mid-point of the passageway, generates a sonic or ultrasonic continuous wave, which propagates upstream and downstream through the passageway. A receiver at the inlet will sense the ultrasonic wave which travels at the speed of sound minus the air speed in the passageway and another at the outlet will sense the ultrasonic wave which travels at the speed of sound plus the air speed in the passageway. Phase comparison of both waves provides a signal proportional to air speed in the passageway which in turn is proportional to the size of the part being gauged.;In another embodiment of the invention, used for differential measurements, the compressed air is supplied at the mid-point of the passageway. An air probe is connected at each end of the passageway. The compressed air will travel from the inlet at the mid-point to both air probes at the outlets. Any difference in the size of the parts being compared by the air probes will cause a difference in air speed between the two branches and result in an output proportional to the difference in sizes. This approach is very useful to make complex measurements such as parallelism, taper, concentricity, squareness or centers distance, by using a specially designed fixture having two air circuits.