Dry Powder Inhaler (DPI) testing requires an added high capacity preseparator or pre-collector between the induction port and stage 0 of cascade. If sampling in environments containing particles larger than 10 micrometres, a pre-separator must be used to prevent particle bouncing and re-entrainment errors. For preventing upper stage mass overloading it is necessary to achieve the specified pressure drop through the device; this feature traps non-inhalable aerosols. To achieve the proper pressure drop of 4 kPa in the inhaler, a higher vacuum flow rate at 60 or 90 L/minute may be needed.

 

Researchers have shown that significant errors will occur with large particles if no pre-separator is used. When using the pre-separator, simply replace the standard inlet cone on the sampler with the preseparator.

 

After ensuring readiness of the setup with all set parameters, dose is released by actuation and further process of cascading starts.