Patent ID: 8744792
Filing Date: 2014-06-03
Classification: G01N,Y02A

Abstract:
1. Measurement apparatus comprising: a chamber; a barrier separating the chamber into first and second regions, wherein the barrier comprises one or more through-holes each with known properties, and wherein the barrier is of a material that is substantially impermeable to air in the absence of any through-holes; a detector arranged to measure a parameter that is related to the diffusive flux of a gas from one region to the other, through the barrier; a processor arranged to calculate a calibration parameter, wherein the calibration parameter can be applied to link a first parameter derived from the measurement by the detector and a second parameter that is derived independently of the measurement by the detector and is related to a theoretical diffusive flux through the barrier, based on the known properties of the through-holes; and data storage means for storing the calibration parameter calculated by the processor, wherein the barrier is replaceable by a further barrier, such that the apparatus is able to determine a calibrated diffusive flux across the further barrier by measuring a parameter with the detector and applying the calibration parameter stored in the data storage means.