Determination of number of particles in air - using electrostatic field with deflection through 180 degrees for use with microbiological counts in pharmaceutical works etc.

摘要

The number of dust particles in air is used to determine the air purity. The number is measured by deflecting the air stream through 180 degrees in the presence of an electric field. The deflection is done in a deflector of hemispherical section. Below this is mounted an electrode immediately above this is placed a droplet of a tacky liq. to collect the dust on a glass slide. Because of the electric field, the particles become charged and are attracted to the electrode located immediately below the droplet. They enter the boundary layer and then remain. Their number is counted by a conventional microscopic technique. Used in measuring air purity in pharmaceutical works, dispensaries etc. esp. to measure microbiological counts. Allows this to be done simply and cheaply using appts. commonly available in medical or pharmaceutical areas and in equipment which is easily operated.