Adaptable filter sampling device

Abstract

An adaptable filter sampling device is provided for localizing the utilized area of a filter medium. The filter sampling device of the present invention includes a filtration cassette having an inlet port, a body portion having an internal cavity, and an outlet port. Positioned within the body portion across the internal cavity is a filtration medium having a predetermined pore size for collecting particles. In addition, the filter sampling device includes an interchangeable restrictor plate made in various forms to enable its use with commercially available filter mediums and filtration cassettes. The restrictor plate includes one or more portals for directing the flow of gases or liquids through the filter sampling device. Preferably, the restrictor plate is positioned anterior and abutting the filter medium in relation to the particle exposure so that a gas or liquid is directed to a defined localized area of the filter medium. The localized area of filtration enables easier microscopic analysis of the filter medium and dramatically reduces the time required to collect and analyze a filtration sample. Moreover, the restrictor plates may have single or multiple portals. The portals may vary in size and shape or, in the case of multiple-restrictor plates, may be identical for replicate and duplicate sampling. Additionally, the portals may be specifically tailored to correspond with a particular microscope's focal views.

1. An adaptable filtration cassette for collecting particulates in liquid or gas comprising:
 a housing having a central conduit, an inlet port, and an outlet port;  
 a substantially planar filtration medium positioned within said housing substantially adjacent to said outlet port; and  
 a removable substantially planar restrictor plate having a portal for localizing the utilized area of said filtration medium, said planar restrictor plate and said filtration medium positioned to abut one another for localizing the utilized area of said filtration medium;  
 said adaptable filter cassette operating in a first and  or second mode, said first mode utilizes substantially all of the surface area of the filter  said filtration medium; and said second mode incorporates said restrictor plate to localize particles to a portion of the filter  filtration medium.  
 
     
     
       2. The adaptable filtration apparatus of  claim 1  wherein the restrictor plate is incorporated into the body  housing of the filtration cassette. 
     
     
       3. The adaptable filtration apparatus of  claim 1  wherein the restrictor plate includes more than one portal. 
     
     
       4. The adaptable filtration apparatus of  claim 1  wherein the restrictor plate includes two portals, each of said two portals being substantially rectangular and having dimensions between 1-5 mm×10-20 mm. 
     
     
       5. The adaptable filtration apparatus of  claim 1  wherein said portal is substantially rectangular and has dimensions between 1-5 mm×10-20 mm. 
     
     
       6. A method for collecting particulates in liquid or gas comprising the steps of:
 providing an adaptable filtration cassette for collecting particulates in liquid or gas including housing having a central conduit, an inlet port, and an outlet port; a substantially planar filtration medium positioned within the housing substantially adjacent to the outlet port; and a removable substantially planar restrictor plate having a portal for localizing the utilized area of the filtration medium, the planar restrictor plate and the planar filtration medium capable of being positioned to abut one another for localizing the utilized area of a filter  the filtration medium;  
 collecting particulates in a first mode by filtering a gas or liquid through the filter  filtration medium without said planar restrictor plate being positioned within said housing; and  
 collecting particulates in a second mode by positioning the restrictor plate so that it abuts and is anterior to a filter  the filtration medium in relation to particle exposure to direct particles to a localized area of the filter  filtration medium and filtering a gas or liquid through the filter  filtration medium.  
 
     
     
       7. The method for collecting particulates in liquid or gas of  claim 6  wherein the filter  filtration medium is substantially round and the restrictor plate's portal is substantially rectangular. 
     
     
       8. The method for collecting particulates in liquid or gas of  claim 6  wherein the filter  filtration medium is substantially round and has a diameter between 10 mm and 47 mm and the restrictor plate's portal is substantially rectangular and has dimensions between 1-5 mm×10-20 mm. 
     
     
       9. The method for collecting particulates in liquid or gas of  claim 6  wherein the restrictor plate includes more than one portal. 
     
     
       10. The method for collecting particulates in liquid or gas of  claim 9  wherein the restrictor plate includes two portals, each of said two portals being substantially and having dimensions between 1-5 mm×10-20 mm. 
     
     
       11. A particulate sampling cassette for simultaneously collecting a plurality of particulate samples in gaseous environments comprising:
   a housing having a central cavity, an inlet and an outlet for connection to a vacuum source;        a filtration sampling collection medium having a predetermined pore size positioned within said housing between said inlet and said outlet; and        a flow restrictor positioned within said housing including a plurality of portals for localizing the utilized area of said filtration sampling collection medium, said flow restrictor and said filtration sampling collection medium positioned adjacent and substantially engaging one another for reducing and localizing the utilized area of said filtration sampling collection medium to produce a plurality of discrete samples corresponding in number to the number of portals within said flow restrictor.     
     
     
       12. The particulate sampling cassette of  claim 11  wherein the flow restrictor includes only two portals. 
     
     
       13. A method for collecting particulates in gaseous environments comprising the steps of:
   providing a particulate sampling cassette including a housing having a central cavity, an inlet and an outlet for connection to a vacuum source, the cassette further having a filtration sampling collection medium having a predetermined pore size positioned within said housing between said inlet and said outlet, and a flow restrictor positioned within said housing including a plurality of portals for localizing the utilized area of the filtration sampling collection medium, the flow restrictor and the filtration sampling collection medium positioned adjacent and substantially engaging one another for reducing and localizing the utilized area of the filtration sampling collection medium to produce a plurality of discrete samples corresponding in number to the number of portals within the flow restrictor;        connecting said outlet to a vacuum source;        simultaneously collecting a plurality of particulate discrete samples corresponding in number to the number of portals within the flow restrictor by filtering a gas or liquid through the flow restrictor and filtration sampling collection medium.