PARTICLE SAMPLERS
7 STAGE CASCADE IMPACTOR
In-Tox Products' Impactors are precision engineered and their careful design provides a number of advantages to the user. The material collected on each stage contains particles having sizes ranging from the cutoff size of the previous stage to the cutoff of the collecting size. Therefore, the analysis of the impactor data may be done without complicated computer programs. It also means that the particles collected on one stage can be re-suspended and used as an aerosol with known size particles.
The precision design and fabrication of the I.T.P. Impactor means a lower wall loss of particles. Typical losses for our impactors are less than 10%. The low loss design is also important to the accurate uniform performance of the impactor. This design allows the air flowing through the impactor to establish the proper flow pattern after passing through one stage before entering the next.
In-Tox Products Cascade Impactors exhibit the sharpest aerosol particle cut-off efficiency curves of any commercially available design. Our cascade impactors can be operated over a range of flow rates without sacrificing collection efficiency.
CYCLONE
The In-Tox Products Cyclone Train is used to determine the particle-size distribution in process streams and to bypass the limitation of Impactors. Cyclone Samplers are advantageous for collecting large samples and in sampling aerosols of high particulate concentration. Cyclones are available in Brass or Stainless Steel and available with a Regular or Elongated Cup.
The Cyclones may be purchase individually. A single Cyclone can be used as a pre-cut for a Cascade Impactor.
DIFFUSION BATTERY
The Serial Flow Diffusion Battery is most useful when determination of submicron particle number is important and when sampling from a stable aerosol source. This type of diffusion battery consists of a series of diffusion chambers placed one behind the other. Each stage provides a longer diffusion length than the stages in front of it. Aerosol is passed through the series of diffusion cells in a laminar stream. Particle penetration through each successive stage in the serial diffusion battery decreases. In order to determine how many particles pass through each stage, a particle counter such as the condensation nucleus counter is used to count the particles in a fraction of the air flowing through each stage.
The Parallel Flow diffusion battery is useful in determining the mass fraction of submicron aerosols or when chemical and microscopic examination of collected submicron aerosol particles is important. This diffusion battery can be used with stable and unstable aerosol sources. This diffusion battery uses stages of increasing diffusion length, but provides for a different arrangement of the stages. In this device, stages of increasing diffusion length are placed parallel to each other. The instrument is arranged so that the same air flow rate passes through each stage or cell of the instrument and each cell samples the input aerosol. Behind each stage an absolute filter counter of similar optical system to count the number of particles passing each stage, the filters can be weighed or analyzed chemically to determine the mass of particles passing through each diffusion stage.
Electrostatic Precipitators (E.S.P.)
Combination Electrostatic Precipitator
The Combination E.S.P. has two collection grids and uses an electrode like the Point-to-Plane model. It uses the same standard transmission electron microscope grid as one collection surface and a 3/8” carbon planchet as the second collection surface for scanning electron microscopy. By symmetrically placing the electrode and collection surfaces, the single needle electrode charges particles to both collection surfaces. The recommended current charge and flow rate is the same, 3 microamperes and 100cc/min., as with the Point-to-Plane.
Concentric Electrostatic Precipitator
The Concentric E.S.P. collects aerosol particles on a foil located inside of an aluminum column. The electrode is centrally located, in the air flow pattern, and with a high voltage corona discharged particles are deposited on the foil. The concentric E.S.P. can be used to collect samples for further analysis or as a cleanup device to extend the life of exhaust filters in an aerosol system. The Concentric E.S.P. can be operated at flow rates up to 125L/min. thus allowing it to be used to sample large air volumes. Although sample collection efficiency may vary in different situations, suggested operating current is 25-30 micro amps. Average collection efficiency for dry particles should exceed 80%.
Point-to-Plane Electrostatic Precipitator
The Point-to-Plane E.S.P. has a single grid collection surface. It uses the standard transmission electron microscope grid as a collection surface. When operated at a current of 3 microamperes, and an aerosol flow rate of 100cc/min. the collection efficiency exceeds 90% for particles down to 0.01 microns diameter
Air Sampling Liquid Impinger
The Air Sampling Liquid Impinger is an instrument used to collect aerosol particles. Aerosol particles are sampled at a known, constant flow rate into a known volume of liquid. Solid particles are counted to determine aerosol concentration. Concentration of liquid or dissolved particles can be determined by chemical analysis.