Measurement of aerosol particle size distribution is important in a host of fields such as inhalation hazard evaluation, atmospheric studies, characterizing lung delivery systems, material synthesis etc. Cascade impactors are the most rugged and widely used systems all over the world for this purpose. However, most commercially available impactors are expensive and in order to make them available at a cost-effective scale, the Particle Aerodynamic Size Separator (PASS), has been designed and developed. It is an import substitute product for aerodynamic particle sizing, based on the principle of inertial impaction and separates particles according to their aerodynamic diameters in the range of 0.53-10 µm in seven class intervals. Being indigenous in design, it may be fabricated on a commercial scale at a cost much less than that of the imported units. This instrument will be of help to several national laboratories and universities for carrying out studies on atmospheric pollution and aerosol characterization.

Sr. No.	Specification	Value
1	Flow rate	45 lpm
2	Maximum number of stages	seven + Back-up filter
3	Effective Cut-off diameter range	0.53 to 10 µm

1. This instrument is useful for occupational monitoring of radioactive and non radioactive environments, arising in the context of material processing, metal cutting, powder handling etc.
2. It is useful for air quality regulators as well as for researchers engaged in various aspects of air pollution and aerosol research.
3. It can also be used by the pharmaceutical industries for characterizing the lung aerosol delivery systems, such as nebulizers and metered dose inhalers.

Measurement of aerosol particle size distribution is important in a host of fields such as inhalation hazard evaluation, atmospheric studies, characterizing lung delivery systems, material synthesis etc. Cascade impactors are the most rugged and widely used systems all over the world for this purpose. However, most commercially available impactors are expensive and in order to make them available at a cost-effective scale, the Particle Aerodynamic Size Separator (PASS), has been designed and developed. It is an import substitute product for aerodynamic particle sizing, based on the principle of inertial impaction and separates particles according to their aerodynamic diameters in the range of 0.53-10µm in seven class intervals. Being indigenous in design, it may be fabricated on a commercial scale at a cost much less than that of the imported units. This instrument will be of help to several national laboratories and universities for carrying out studies on atmospheric pollution and aerosol characterization

This instrument is useful for occupational monitoring of radioactive and non radioactive environments, arising in the context of material processing, metal cutting, powder handling etc. It is useful for air quality regulators as well as for researchers engaged in various aspects of air pollution and aerosol research. It can also be used by the pharmaceutical industries for characterizing the lung aerosol delivery systems, such as nebulizers and metered dose inhalers.

This device, while being less expensive, has a few additional features over the presently available imported impactors. These are as follows:

1. It operates at a higher flow rate, thus enabling a quicker collection of samples for analysis.
2. It can be loaded with any desired number of stages other than the maximum of seven, depending upon the requirement of the user.
3. It has a new design for the collection plates to reduce inter-stage losses.
4. It may be easily assembled by the use of stud-wing nut arrangement.

Sr. No.	Specification	Value
1	Flow rate	45 lpm
2	Maximum number of stages	seven + Back-up filter
3	Effective Cut-off diameter range	0.53 to 10 µm

The impactor stages and the collection plates are made of aluminum alloy of grade 6061 condition T6 (IS 65032) while the connecting adopter and fasteners are made of brass. The unit is made leak proof with the use of teflon/neoprene gaskets. All the materials in the assembly are readily available in the local market.

A full-scale workshop equipped with the following machine and inspection facility is required to manufacture the unit.

1. Precision lathe to manufacture components with IT6 grade tolerance.
2. Precision micro-drilling facility suitable to use micro-grain cartridge drills to drill holes of diameters as small as 0.25 mm. This facility shall be equipped with indexing arrangement.
3. Linear measuring equipments like out-side micrometers inside micrometers, digital/ dial vernier calipers, pin gauges etc.
4. Optical Magnifying unit with at least 30 'X' magnification.

Properly trained one skilled turner and one machinist along a quality control personnel to machine the component and a qualified engineer to supervise the work and to calibrate the unit are required.