Pneumatic distance measurement - gives rapid results using gas nozzle outlet flow speed measurement and movable calibration ring

摘要

A pneumatic measurement device measures the distance between a gas nozzle (20) and a workpiece or surface from the flow speed out of the nozzle. The measurement time and measurement result drift are essentially reduced compared to similar devices. The device may be used for measuring the hole diameter. A pressure increase device (21) operated by the relative motion between the measurement device and the workpiece moves between a standbay position, in which it lies in the nozzle (20) outlet flow, and a measurement position, in which it leaves the nozzle unobstructed. The pressure increase element (21) can act as a calibration unit. When the pressure increase element, which may be a ring (21), is in the standby position, its distance from the nozzle is slightly smaller than the measurement distance.