公开(公告)号：US3526461A

公开(公告)日：1970-09-01

申请号：US3526461D

申请日：1967-04-24

Applicant: SAAB AB

Inventor： LINDAHL BO OSCAR ,  LAMME VALENTIN

IPC: G01N15/06 ,  G01N21/47 ,  G01N21/53 ,  G01N21/94 ,  G01N1/00 ,  G01N21/00 ,  G01N33/28

CPC classification number: G01N21/94 ,  G01N15/0618 ,  G01N21/4738 ,  G01N21/53

公开(公告)号：GB1145657A

公开(公告)日：1969-03-19

申请号：GB1953167

申请日：1967-04-27

Applicant: SAAB AB

Inventor： LINDAHL BO OSCAR ,  LAMME VALENTIN

IPC: G01N15/06 ,  G01N21/47 ,  G01N21/53 ,  G01N21/94

Abstract: 1,145,657. Measuring particle concentration in atmosphere. SAAB A.B. April 27, 1967 [April 27, 1966], No.19531/67. Heading G1A. In an arrangement for determining the concentration of particles in a gaseous atmosphere a plate is placed in the atmosphere for a period of time determined by a time switch and is then exposed to a beam of light parallel to the surface, the amount of light deflected in a direction away from the plate being measured as an indication of the number of settled particles. A portable apparatus includes a withdrawable and retractable drawer in which the plate is accommodated, means for adjusting the plate exposure time, a meter and range change switch, and an optical inspection and sizing tube. The light source is fed from a voltage regulated supply and is directed across the plate surface through lenses and an aperture. Light deflected by the particles in a direction perpendicular to the plate is detected by a photocell, and converted to an electrical signal at indicating by its voltage current or frequency the number of particles. In a modified arrangement two beams of light are directed at right angles across adjacent sides of the plate to vertical mirrors which return the beams across the plate so that the particles are illuminated from all sides to improve sensitivity. The plates may be exposed in remote spots and brought in sealed containers to the measuring apparatus.