Patent ID: 6212941
Filing Date: 2001-04-10
Classification: G01N

Abstract:
Permeameter of a fluid driven type comprising a measuring head enabling a test piece with at least 2 sides thereof to be at least partially imprisoned in an airtight manner, this measuring head comprising a pair of chambers opening respectively onto said sides of the test piece, one of these chambers being connected to a measuring circuit successively comprising a series connection of at least one analog output flow meter for measuring a fluid flow value or a fluid flow rate from said test piece and a pumping means capable of generating pressure or a partial vacuum upon said test piece at a certain pressure value in the measuring circuit, a pressure sensor and, an adjusting means being provided to maintain the measuring circuit at a given pressure or partial vacuum,wherein said measuring circuit comprises an electronic circuit comprising a plurality of calibrated amplifiers of which the inputs are connected to the analog output(s) of the flow meter(s) and of which the amplifier outputs are connected to respective inputs of an analog output multiplexer driven by an electronic processor, the analog output of this multiplexer being connected to an analog-to-digital converter of which the A/D converter output is connected to the processor for automated determination of a set of permeability results obtained for said test piece in terms of a digital flow rate value.