Patent ID: 7159446
Filing Date: 2007-01-09
Classification: G01N

Abstract:
1. In a particulate matter concentration measuring apparatus for continuously measuring a concentration of particulate matter in a sample gas collected in a collecting region formed on a collecting member, the collecting region being formed by drawing the sample gas through a cross-sectional area of the collecting member from one face side to the other face side, wherein the collecting member is a filter tape roll, the filter tape roll includes a porous film made of a fluorine resin for trapping particulate matter in the collecting region, the filter tape roll includes a reinforcing layer of a non-woven fabric on the porous film, the reinforcing layer allows the transmission of the sample gas and enables sufficient strength for movement of a portion of the filter tape relative to the collecting region to provide a sequential series of measurements at spaced positions along the filter tape, and a supporting means for supporting a portion of filter tape unwound from the filter tape roll in the collecting region, the supporting means having a plurality of exhaust holes for discharging the sample gas passing through the portion of filter tape and supporting the portion of filter tape against being deformed in the collecting region, the supporting means having one exhaust hole at a central position and at least three exhaust holes at a peripheral portion.