Aerosol particle monitor

Claim 2

Apparatus for measuring the concentration of particles suspended in a fluid, said apparatus comprising: means defining a convergent nozzle for said fluid; means for inducing a stream of said fluid to flow through said nozzle, said nozzle terminating in a relatively small jet opening thereby providing a relatively high fluid exit velocity; means for supporting a particle receiving medium in alignment with the exiting fluid jet to receive by impaction particles borne by said fluid stream; a radiation source mounted on one side of said medium and said nozzle in alignment with said opening for providing beta radiation directed through said medium; and a radiation detector mounted on the opposite side of said nozzle having a sensitive area in alignment with said source and said jet opening for receiving radiation transmitted from said source through said medium and material impacted thereon, whereby the rate of change of the level of radiation measured by said detector varies as a function of the concentration of particles suspended in said fluid stream.

Claim 3

Apparatus for measuring the concentration of aerosol particles suspended in a gas, said apparatus comprising: means defining a convergent nozzle for said gas; means for inducing a stream of said gas to flow through said nozzle, said nozzle terminating in a relatively small jet opening thereby providing a relatively high exit velocity; means in alignment with the exiting fluid jet to receive by impaction particles borne by said gas stream; a beta radiation source mounted on one side of said receiving means and said nozzle and in alignment with said jet opening for providing beta radiation directed toward said jet opening; and a beta radiation detector mounted on the opposite side of said nozzle and having a sensitive area corresponding in size to said jet opening, said sensitive area being in alignment with said source and said jet opening for receiving radiation transmitted back from said source, whereby the rate of change of the level of radiation measured by said detector varies as a function of the concentration of particles suspended in said fluid stream.

Claim 4

Apparatus for measuring the concentration of aerosol particles suspended in a gas, said apparatus comprising: means defining a convergent nozzle for said gas; means for inducing a stream of said gas to flow through said nozzle, said nozzle terminating in a relatively small jet opening thereby providing a relatively high exit velocity; means in alignment with the exiting fluid jet to receive by impaction particles borne by said gas stream; a beta radiation source mounted on one side of said receiving means and said nozzle and in alignment with said jet opening for providing beta radiation directed toward said jet opening; and a beta radiation detector mounted on the opposite side of said nozzle and having a sensitive area corresponding in size to said jet opening, said sensitive area being in alignment with said source and said jet opening for receiving radiation transmitted back from said source, whereby the rate of change of the level of radiation measured by said detector varies as a function of the concentration of particles suspended in said fluid stream.

Claim 5

Apparatus for measuring the concentration of dust particles suspended in air, said apparatus comprising: means defining a convergent nozzle; means for drawing a stream of said air through said nozzle, said nozzle terminating in a relatively small jet opening thereby providing a relatively high exit velocity; a particle receiving medium in alignment with the exiting jet to receive by impaction particles borne by said air stream; a carbon 14 beta radiation source mounted on the downstream side of said medium in alignment with said jet opening for providing beta radiation directed through said medium toward said jet opening; and a Geiger tube detector mounted on the upstream side of said nozzle and having a sensitive area corresponding to said jet opening, said sensitive area being in alignment with said source and said jet opening for receiving beta radiation transmitted back from said source through said medium and particulate material impacted thereon, whereby the rate of change of the level of beta radiation measured by said detector varies as a function of the concentration of particles suspended in said air.

Claim 6

Apparatus for measuring the concentration of dust particles suspended in air, said apparatus comprising: means defining a convergent nozzle; means for drawing a stream of said air through said nozzle, said nozzle terminating in a relatively small jet opening thereby providing a relatively high exit velocity; a particle receiving medium in alignment with the exiting jet to receive by impaction particles borne by said air stream; a carbon 14 beta radiation source mounted on the downstream side of said medium in alignment with said jet opening for providing beta radiation directed through said medium toward said jet opening; and a Geiger tube detector mounted on the upstream side of said nozzle and having a sensitive area corresponding to said jet opening, said sensitive area being in alignment with said source and said jet opening for receiving beta radiation transmitted back from said source through said medium and particulate material impacted thereon, whereby the rate of change of the level of beta radiation measured by said detector varies as a function of the concentration of particles suspended in said air.

Claim 7

Apparatus for measuring the concentration of aerosol particles suspended in air, said apparatus comprising: a first body member having an air inlet therein; a second body member having a portion defining a convergent nozzle; a third body member including means for applying a vacuum for drawing a stream of said air through said nozzle, said nozzle terminating in a relatively small jet opening thereby providing a relatively high exit velocity; A plastic film particle receiving medium supported in alignment with the exiting air jet to receive, by impaction, particles borne by said air stream; a carbon 14 beta radiation source mounted on the downstream side of said medium in alignment with said jet opening for providing beta radiation directed through said medium toward said jet opening; and a Geiger tube detector mounted on said first body member on the upstream side of said nozzle and having a sensitive area corresponding in size to said jet opening, said sensitive area being in alignment with said source and said jet opening for receiving beta radiation transmitted back from said source through said medium and particulate material impacted thereon, whereby the rate of change of the level of beta radiation measured by said detector varies as a function of the concentration of particles suspended in said air.

Claim 8

Apparatus for measuring the concentration of aerosol particles suspended in air, said apparatus comprising: a first body member having an air inlet therein; a second body member having a portion defining a convergent nozzle; a third body member including means for applying a vacuum for drawing a stream of said air through said nozzle, said nozzle terminating in a relatively small jet opening thereby providing a relatively high exit velocity; A plastic film particle receiving medium supported in alignment with the exiting air jet to receive, by impaction, particles borne by said air stream; a carbon 14 beta radiation source mounted on the downstream side of said medium in alignment with said jet opening for providing beta radiation directed through said medium toward said jet opening; and a Geiger tube detector mounted on said first body member on the upstream side of said nozzle and having a sensitive area corresponding in size to said jet opening, said sensitive area being in alignment with said source and said jet opening for receiving beta radiation transmitted back from said source through said medium and particulate material impacted thereon, whereby the rate of change of the level of beta radiation measured by said detector varies as a function of the concentration of particles suspended in said air.