Abstract: A gas permeability measurement apparatus and a gas permeability measurement method, including a first chamber filled with a measurement gas and maintained at a constant pressure, a second chamber connected in series to the first chamber, a third chamber connected in series to the second chamber, and a separating plate having a through-hole and separating the second chamber and the third chamber from each other. A conductance adjusting part is disposed between the second and third chambers to adjust conductance passing through the through-hole of the separating plate. A vacuum pump is connected to the third chamber to exhaust the third chamber. A differential pressure gauge measures differential pressure between the second and third chambers. A sample is disposed between the first and second chambers. The measurement gas is delivered to the second chamber after permeating the sample, and the conductance adjusting part sequentially provides at least two different conductances.

Abstract: An apparatus and method for in-situ calibration of a vacuum gauge by absolute method and comparison method, which can carry out absolute calibration using a static type standard for measuring pressures of vacuum chambers by expanding and moving gas between four vacuum chambers of different volumes in order, and comparison calibration of vacuum gauges in an in-situ state without movement of the vacuum gauges according to a method for controlling gas flow through an orifice using a calibrated standard vacuum gauge. Thus, the absolute calibration and the comparative calibration of the vacuum gauges which have been separately carried out by different apparatuses till now can be carried out by just one apparatus, whereby economical efficiency and convenience in calibration of vacuum gauges are maximized.

Abstract: Disclosed therein is apparatus and method for in-situ calibration of a vacuum gauge by absolute method and comparison method, which can carry out absolute calibration using a static type standard for measuring pressures of vacuum chambers by expanding and moving gas to the vacuum chambers of different volumes in order and comparison calibration of vacuum gauges in an in-situ state without movement of the vacuum gauges according to a method for controlling gas flow through an orifice using a calibrated standard vacuum gauge. The present invention includes a technology for combining an absolute calibration of a standard vacuum gauge by a static method and a comparative calibration of a vacuum gauge by a method for controlling a gas flow through an orifice, technologies for generating and calibrating standard pressure from a low vacuum to a high vacuum, and a technology of comparative calibration of the vacuum gauge by a method for stabilizing the gas flow through the orifice.